path: root/ganarchy.py

                      

#!/usr/bin/env python3

# GAnarchy - project homepage generator
# Copyright (C) 2019  Soni L.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

import sqlite3
import click
import os
import subprocess
import hashlib
import hmac
import jinja2
import re

MIGRATIONS = {
        "gen-index": (
                (
                    """ALTER TABLE "config" ADD COLUMN "title" TEXT"""),
                (),
                "supports generating an index page"
            ),
        "better-project-management": (
                (
                    """ALTER TABLE "repos" ADD COLUMN "branch" TEXT""",
                    """ALTER TABLE "repos" ADD COLUMN "project" TEXT""",
                    """CREATE UNIQUE INDEX "repos_url_branch_project" ON "repos" ("url", "branch", "project")""",
                    """CREATE INDEX "repos_project" ON "repos" ("project")""",
                    """ALTER TABLE "repo_history" ADD COLUMN "branch" TEXT""",
                    """ALTER TABLE "repo_history" ADD COLUMN "project" TEXT""",
                    """CREATE INDEX "repo_history_url_branch_project" ON "repo_history" ("url", "branch", "project")"""),
                (
                    """DELETE FROM "repos" WHERE "branch" IS NOT NULL OR "project" IS NOT NULL""",
                    """DELETE FROM "repo_history" WHERE "branch" IS NOT NULL OR "project" IS NOT NULL"""),
                "supports multiple projects, and allows choosing non-default branches"
            ),
        "test": (
                ("""-- apply""",),
                ("""-- revert""",),
                "does nothing"
            )
        }

data_home = os.environ.get('XDG_DATA_HOME', '')
if not data_home:
    data_home = os.environ['HOME'] + '/.local/share'
data_home = data_home + "/ganarchy"

cache_home = os.environ.get('XDG_CACHE_HOME', '')
if not cache_home:
    cache_home = os.environ['HOME'] + '/.cache'
cache_home = cache_home + "/ganarchy"

config_home = os.environ.get('XDG_CONFIG_HOME', '')
if not config_home:
    config_home = os.environ['HOME'] + '/.config'
config_home = config_home + "/ganarchy"

config_dirs = os.environ.get('XDG_CONFIG_DIRS', '')
if not config_dirs:
    config_dirs = '/etc/xdg'
# TODO check if this is correct
config_dirs = [config_dir + "/ganarchy" for config_dir in config_dirs.split(':')]

def get_template_loader():
    from jinja2 import DictLoader, FileSystemLoader, ChoiceLoader
    return ChoiceLoader([
        FileSystemLoader([config_home + "/templates"] + [config_dir + "/templates" for config_dir in config_dirs]),
        DictLoader({
            ## index.html
            'index.html': """<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8" />
        <!--
        GAnarchy - project homepage generator
        Copyright (C) 2019  Soni L.

        This program is free software: you can redistribute it and/or modify
        it under the terms of the GNU Affero General Public License as published by
        the Free Software Foundation, either version 3 of the License, or
        (at your option) any later version.

        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU Affero General Public License for more details.

        You should have received a copy of the GNU Affero General Public License
        along with this program.  If not, see <https://www.gnu.org/licenses/>.
        -->
        <title>{{ ganarchy.title|e }}</title>
        <meta name="description" content="{{ ganarchy.title|e }}" />
        <!--if your browser doesn't like the following, use a different browser.-->
        <script type="application/javascript" src="/index.js"></script>
    </head>
    <body>
        <h1>{{ ganarchy.title|e }}</h1>
        <p>This is {{ ganarchy.title|e }}. Currently tracking the following projects:</p>
        <ul>
        {% for project in ganarchy.projects -%}
            <li><a href="/project/{{ project.commit|e }}">{{ project.title|e }}</a>: {{ project.description|e }}</li>
        {% endfor -%}
        </ul>
        <p>Powered by <a href="https://ganarchy.autistic.space/">GAnarchy</a>. AGPLv3-licensed. <a href="https://cybre.tech/SoniEx2/ganarchy">Source Code</a>.</p>
        <p>
            <a href="{{ ganarchy.base_url|e }}" onclick="event.preventDefault(); navigator.registerProtocolHandler('web+ganarchy', this.href + '?url=%s', 'GAnarchy');">Register web+ganarchy: URI handler</a>.
        </p>
    </body>
</html>
""",
            ## project.html FIXME
            'project.html': """<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8" />
        <!--
        GAnarchy - project homepage generator
        Copyright (C) 2019  Soni L.

        This program is free software: you can redistribute it and/or modify
        it under the terms of the GNU Affero General Public License as published by
        the Free Software Foundation, either version 3 of the License, or
        (at your option) any later version.

        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU Affero General Public License for more details.

        You should have received a copy of the GNU Affero General Public License
        along with this program.  If not, see <https://www.gnu.org/licenses/>.
        -->
        <title>{{ project_title|e }}</title>
        {% if project_desc %}<meta name="description" content="{{ project_desc|e }}" />{% endif %}
        <style type="text/css">.branchname { color: #808080; font-style: italic; }</style>
    </head>
    <body>
        <h1>{{ project_title|e }}</h1>
        <p>Tracking <span id="project_commit"><a href="web+ganarchy:{{ project_commit }}">{{ project_commit }}</a></span></p>
        <div id="project_body"><p>{{ project_body|e|replace("\n\n", "</p><p>") }}</p></div>
        <ul>
        {% for url, msg, img, branch in repos -%}
            <li><a href="{{ url|e }}">{{ url|e }}</a>{% if branch %} <span class="branchname">[{{ branch|e }}]</span>{% endif %}: {{ msg|e }}</li>
        {% endfor -%}
        </ul>
        <p>Powered by <a href="https://ganarchy.autistic.space/">GAnarchy</a>. AGPLv3-licensed. <a href="https://cybre.tech/SoniEx2/ganarchy">Source Code</a>.</p>
        <p>
            <a href="/">Main page</a>.
            <a href="{{ base_url|e }}" onclick="event.preventDefault(); navigator.registerProtocolHandler('web+ganarchy', this.href + '?url=%s', 'GAnarchy');">Register web+ganarchy: URI handler</a>.
        </p>
    </body>
</html>
""",
            ## history.svg FIXME
            'history.svg': """""",
        })
    ])


@click.group()
def ganarchy():
    pass

@ganarchy.command()
def initdb():
    """Initializes the ganarchy database."""
    os.makedirs(data_home, exist_ok=True)
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''CREATE TABLE "repos" ("url" TEXT PRIMARY KEY, "active" INT, "branch" TEXT, "project" TEXT)''')
    c.execute('''CREATE UNIQUE INDEX "repos_url_branch_project" ON "repos" ("url", "branch", "project")''')
    c.execute('''CREATE INDEX "repos_project" ON "repos" ("project")''')
    c.execute('''CREATE INDEX "repos_active" ON "repos" ("active")''')
    c.execute('''CREATE TABLE "repo_history" ("entry" INTEGER PRIMARY KEY ASC AUTOINCREMENT, "url" TEXT, "count" INTEGER, "head_commit" TEXT, "branch" TEXT, "project" TEXT)''')
    c.execute('''CREATE INDEX "repo_history_url_branch_project" ON "repo_history" ("url", "branch", "project")''')
    c.execute('''CREATE TABLE "config" ("git_commit" TEXT, "base_url" TEXT, "title" TEXT)''')
    c.execute('''INSERT INTO "config" VALUES ('', '', '')''')
    conn.commit()
    conn.close()

@ganarchy.command()
@click.argument('commit')
def set_commit(commit):
    """Sets the commit that represents the project."""
    if not re.fullmatch("[a-fA-F0-9]{40}", commit):
        raise click.BadArgumentUsage("COMMIT must be a git commit hash")
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''UPDATE "config" SET "git_commit"=?''', (commit,))
    conn.commit()
    conn.close()

@ganarchy.command()
@click.argument('base-url')
def set_base_url(base_url):
    """Sets the GAnarchy instance's base URL. Used for the URI handler."""
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''UPDATE "config" SET "base_url"=?''', (base_url,))
    conn.commit()
    conn.close()

@ganarchy.command()
@click.argument('title')
def set_title(title):
    """Sets the GAnarchy instance's title. This title is displayed on the index."""
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''UPDATE "config" SET "title"=?''', (title,))
    conn.commit()
    conn.close()

# TODO move --branch into here?
@ganarchy.group()
def repo():
    """Modifies repos to track."""

@repo.command()
@click.option('--branch', default=None, help="Sets the branch to be used for the repo")
@click.option('--project', default=None, help="Sets the project commit to be used for the repo")
@click.option('--disabled', default=False, is_flag=True, help="Mark the repo as disabled")
@click.argument('url')
def add(branch, project, disabled, url):
    """Adds a repo to track."""
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''SELECT "git_commit", "base_url" FROM "config"''')
    (project_commit, base_url) = c.fetchone()
    if project_commit == project:
        project = None
    c.execute('''INSERT INTO "repos" ("url", "active", "branch", "project") VALUES (?, ?, ?, ?)''', (url, int(not disabled), branch, project))
    conn.commit()
    conn.close()

@repo.command()
@click.option('--branch', default=None, help="Sets the branch to be used for the repo")
@click.option('--project', default=None, help="Sets the project commit to be used for the repo")
@click.argument('url')
def enable(branch, project, url):
    """Enables tracking of a repo."""
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''SELECT "git_commit", "base_url" FROM "config"''')
    (project_commit, base_url) = c.fetchone()
    if project_commit == project:
        project = None
    c.execute('''UPDATE "repos" SET "active"=1 WHERE "url"=? AND "branch" IS ? AND "project" IS ?''', (url, branch, project))
    conn.commit()
    conn.close()

@repo.command()
@click.option('--branch', default=None, help="Sets the branch to be used for the repo")
@click.option('--project', default=None, help="Sets the project commit to be used for the repo")
@click.argument('url')
def disable(branch, project, url):
    """Disables tracking of a repo."""
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''SELECT "git_commit", "base_url" FROM "config"''')
    (project_commit, base_url) = c.fetchone()
    if project_commit == project:
        project = None
    c.execute('''UPDATE repos SET "active"=0 WHERE "url"=? AND "branch" IS ? AND "project" IS ?''', (url, branch, project))
    conn.commit()
    conn.close()

@repo.command()
@click.option('--branch', default=None, help="Sets the branch to be used for the repo")
@click.option('--project', default=None, help="Sets the project commit to be used for the repo")
@click.argument('url')
def remove(branch, project, url):
    """Stops tracking a repo."""
    click.confirm("WARNING: This operation does not delete the commits associated with the given repo! Are you sure you want to continue? This operation cannot be undone.")
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''SELECT "git_commit", "base_url" FROM "config"''')
    (project_commit, base_url) = c.fetchone()
    if project_commit == project:
        project = None
    c.execute('''DELETE FROM "repos" WHERE "url"=? AND "branch" IS ? AND "project" IS ?''', (url, branch, project))
    c.execute('''DELETE FROM "repo_history" WHERE "url"=? AND "branch" IS ? AND "project" IS ?''', (url, branch, project))
    conn.commit()
    conn.close()

def migrations():
    @ganarchy.group()
    def migrations():
        """Modifies the DB to work with a newer/older version.

        WARNING: THIS COMMAND CAN BE EXTREMELY DESTRUCTIVE!"""

    @migrations.command()
    @click.argument('migration')
    def apply(migration):
        """Applies the migration with the given name."""
        conn = sqlite3.connect(data_home + "/ganarchy.db")
        c = conn.cursor()
        click.echo(MIGRATIONS[migration][0])
        for migration in MIGRATIONS[migration][0]:
            c.execute(migration)
        conn.commit()
        conn.close()

    @click.argument('migration')
    @migrations.command()
    def revert(migration):
        """Reverts the migration with the given name."""
        conn = sqlite3.connect(data_home + "/ganarchy.db")
        c = conn.cursor()
        click.echo(MIGRATIONS[migration][1])
        for migration in MIGRATIONS[migration][1]:
            c.execute(migration)
        conn.commit()
        conn.close()

    @click.argument('migration', required=False)
    @migrations.command()
    def info(migration):
        """Shows information about the migration with the given name."""
        if not migration:
            # TODO could be improved
            click.echo(MIGRATIONS.keys())
        else:
            click.echo(MIGRATIONS[migration][2])

migrations()

class GitError(LookupError):
    """Raised when a git operation fails, generally due to a missing commit or branch, or network connection issues."""
    pass

class Repo:
    def __init__(self, dbconn, project, url, branch, list_metadata=False):
        self.url = url
        self.branch = branch
        self.project_commit = project.commit

        if not branch:
            self.branchname = "gan" + hashlib.sha256(url.encode("utf-8")).hexdigest()
            self.head = "HEAD"
        else:
            self.branchname = "gan" + hmac.new(branch.encode("utf-8"), url.encode("utf-8"), "sha256").hexdigest()
            self.head = "refs/heads/" + branch

        try:
            self.hash = subprocess.check_output(["git", "-C", cache_home, "show", self.branchname, "-s", "--format=%H", "--"], stderr=subprocess.DEVNULL).decode("utf-8").strip()
        except subprocess.CalledProcessError:
            self.hash = None

        self.message = None
        if list_metadata:
            try:
                self.fetch_metadata()
            except GitError:
                pass

    def fetch_metadata(self):
        try:
            self.message = subprocess.check_output(["git", "-C", cache_home, "show", self.branchname, "-s", "--format=%B", "--"], stderr=subprocess.DEVNULL).decode("utf-8", "replace")
        except subprocess.CalledProcessError as e:
            raise GitError from e

    def update(self): # FIXME?
        try:
            subprocess.check_output(["git", "-C", cache_home, "fetch", "-q", self.url, "+" + self.head + ":" + self.branchname], stderr=subprocess.STDOUT)
        except subprocess.CalledProcessError as e:
            # This may error for various reasons, but some are important: dead links, etc
            click.echo(e.output, err=True)
            return None
        pre_hash = self.hash
        post_hash = subprocess.check_output(["git", "-C", cache_home, "show", self.branchname, "-s", "--format=%H", "--"], stderr=subprocess.DEVNULL).decode("utf-8").strip()
        self.hash = post_hash
        if not pre_hash:
            pre_hash = post_hash
        try:
            count = int(subprocess.check_output(["git", "-C", cache_home, "rev-list", "--count", pre_hash + ".." + post_hash, "--"]).decode("utf-8").strip())
        except subprocess.CalledProcessError:
            count = 0  # force-pushed
        try:
            subprocess.check_call(["git", "-C", cache_home, "merge-base", "--is-ancestor", self.project_commit, self.branchname], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
            self.fetch_metadata()
            return count, post_hash, self.message
        except (subprocess.CalledProcessError, GitError) as e:
            click.echo(e, err=True)
            return None

class Project:
    def __init__(self, dbconn, ganarchy, project_commit, list_repos=False):
        self.commit = project_commit
        if ganarchy.project_commit == project_commit:
            project_commit = None
        self.refresh_metadata()
        if list_repos:
            repos = []
            with dbconn:
                for (e, url, branch) in dbconn.execute('''SELECT "max"("e"), "url", "branch" FROM (SELECT "max"("T1"."entry") "e", "T1"."url", "T1"."branch" FROM "repo_history" "T1"
                                                                    WHERE (SELECT "active" FROM "repos" "T2" WHERE "url" = "T1"."url" AND "branch" IS "T1"."branch" AND "project" IS ?1)
                                                                    GROUP BY "T1"."url", "T1"."branch"
                                                                    UNION
                                                                    SELECT null, "T3"."url", "T3"."branch" FROM "repos" "T3" WHERE "active" AND "project" IS ?1)
                                           GROUP BY "url" ORDER BY "e"''', (project_commit,)):
                    repos.append(Repo(dbconn, self, url, branch))
            self.repos = repos
        else:
            self.repos = None

    def refresh_metadata(self):
        try:
            project = subprocess.check_output(["git", "-C", cache_home, "show", self.commit, "-s", "--format=%B", "--"], stderr=subprocess.DEVNULL).decode("utf-8", "replace")
            project_title, project_desc = (lambda x: x.groups() if x is not None else ('', None))(re.fullmatch('^\\[Project\\]\s+(.+?)(?:\n\n(.+))?$', project, flags=re.ASCII|re.DOTALL|re.IGNORECASE))
            if not project_title.strip():
                project_title, project_desc = ("Error parsing project commit",)*2
            if project_desc:
                project_desc = project_desc.strip()
            self.commit_body = project
            self.title = project_title
            self.description = project_desc
        except subprocess.CalledProcessError:
            self.commit_body = None
            self.title = None
            self.description = None

    def update(self):
        # TODO
        self.refresh_metadata()

class GAnarchy:
    def __init__(self, dbconn, list_projects=False):
        with dbconn:
            # TODO
            #(project_commit, base_url, title) = dbconn.execute('''SELECT "git_commit", "base_url", "title" FROM "config"''').fetchone()
            (project_commit, base_url) = dbconn.execute('''SELECT "git_commit", "base_url" FROM "config"''').fetchone()
            title = None
            self.project_commit = project_commit
            self.base_url = base_url
            if not base_url:
                pass ## TODO
            if not title:
                from urllib.parse import urlparse
                title = "GAnarchy on " + urlparse(base_url).hostname
            self.title = title
        if list_projects:
            projects = []
            with dbconn:
                for (project,) in dbconn.execute('''SELECT DISTINCT "project" FROM "repos" '''): # FIXME? *maybe* sort by activity in the future
                    if project == None:
                        project = self.project_commit
                    projects.append(Project(dbconn, ganarchy, project))
            projects.sort(key=lambda project: project.title)
            self.projects = projects
        else:
            self.projects = None


@ganarchy.command()
@click.argument('project', required=False)
def cron_target(project):
    """Runs ganarchy as a cron target."""
    # make sure the cache dir exists
    os.makedirs(cache_home, exist_ok=True)
    # make sure it is a git repo
    subprocess.call(["git", "-C", cache_home, "init", "-q"])
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    instance = GAnarchy(conn, list_projects=project=="index")
    env = jinja2.Environment(loader=get_template_loader(), autoescape=False)
    if project == "index":
        # render the index
        template = env.get_template('index.html')
        click.echo(template.render(ganarchy = instance))
        return
    project_commit = instance.project_commit
    base_url = instance.base_url
    if not base_url or not (project or project_commit):
        click.echo("No base URL or project commit specified", err=True)
        return
    if project_commit == project:
        project = None
    elif project is not None:
        project_commit = project
    entries = []
    generate_html = []
    c = conn.cursor()
    p = Project(conn, instance, project_commit, list_repos=True)
    # FIXME: this should be moved into Project.update()
    for repo in p.repos:
        result = repo.update()
        if result is not None:
            count, post_hash, msg = result
            entries.append((repo.url, count, post_hash, repo.branch, project))
            generate_html.append((repo.url, msg, count, repo.branch))
    p.refresh_metadata()
    # sort stuff twice because reasons
    entries.sort(key=lambda x: x[1], reverse=True)
    generate_html.sort(key=lambda x: x[2], reverse=True)
    c.executemany('''INSERT INTO "repo_history" ("url", "count", "head_commit", "branch", "project") VALUES (?, ?, ?, ?, ?)''', entries)
    conn.commit()
    html_entries = []
    for (url, msg, count, branch) in generate_html:
        history = c.execute('''SELECT "count" FROM "repo_history" WHERE "url" = ? AND "branch" IS ? AND "project" IS ? ORDER BY "entry" ASC''', (url, branch, project)).fetchall()
        # TODO process history into SVG
        html_entries.append((url, msg, "", branch))
    template = env.get_template('project.html')
    click.echo(template.render(project_title  = p.title,
                               project_desc   = p.description,
                               project_body   = p.commit_body,
                               project_commit = p.commit,
                               repos          = html_entries,
                               base_url       = base_url,
                               # I don't think this thing supports deprecating the above?
                               project        = p,
                               ganarchy       = instance))

if __name__ == "__main__":
    ganarchy()
#!/usr/bin/env python3

# GAnarchy - project homepage generator
# Copyright (C) 2019  Soni L.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

import sqlite3
import click
import os
import subprocess
import hashlib
import hmac
import jinja2
import re

MIGRATIONS = {
        "gen-index": (
                (
                    """ALTER TABLE "config" ADD COLUMN "title" TEXT"""),
                (),
                "supports generating an index page"
            ),
        "better-project-management": (
                (
                    """ALTER TABLE "repos" ADD COLUMN "branch" TEXT""",
                    """ALTER TABLE "repos" ADD COLUMN "project" TEXT""",
                    """CREATE UNIQUE INDEX "repos_url_branch_project" ON "repos" ("url", "branch", "project")""",
                    """CREATE INDEX "repos_project" ON "repos" ("project")""",
                    """ALTER TABLE "repo_history" ADD COLUMN "branch" TEXT""",
                    """ALTER TABLE "repo_history" ADD COLUMN "project" TEXT""",
                    """CREATE INDEX "repo_history_url_branch_project" ON "repo_history" ("url", "branch", "project")"""),
                (
                    """DELETE FROM "repos" WHERE "branch" IS NOT NULL OR "project" IS NOT NULL""",
                    """DELETE FROM "repo_history" WHERE "branch" IS NOT NULL OR "project" IS NOT NULL"""),
                "supports multiple projects, and allows choosing non-default branches"
            ),
        "test": (
                ("""-- apply""",),
                ("""-- revert""",),
                "does nothing"
            )
        }

data_home = os.environ.get('XDG_DATA_HOME', '')
if not data_home:
    data_home = os.environ['HOME'] + '/.local/share'
data_home = data_home + "/ganarchy"

cache_home = os.environ.get('XDG_CACHE_HOME', '')
if not cache_home:
    cache_home = os.environ['HOME'] + '/.cache'
cache_home = cache_home + "/ganarchy"

config_home = os.environ.get('XDG_CONFIG_HOME', '')
if not config_home:
    config_home = os.environ['HOME'] + '/.config'
config_home = config_home + "/ganarchy"

config_dirs = os.environ.get('XDG_CONFIG_DIRS', '')
if not config_dirs:
    config_dirs = '/etc/xdg'
# TODO check if this is correct
config_dirs = [config_dir + "/ganarchy" for config_dir in config_dirs.split(':')]

def get_template_loader():
    from jinja2 import DictLoader, FileSystemLoader, ChoiceLoader
    return ChoiceLoader([
        FileSystemLoader([config_home + "/templates"] + [config_dir + "/templates" for config_dir in config_dirs]),
        DictLoader({
            ## index.html
            'index.html': """<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8" />
        <!--
        GAnarchy - project homepage generator
        Copyright (C) 2019  Soni L.

        This program is free software: you can redistribute it and/or modify
        it under the terms of the GNU Affero General Public License as published by
        the Free Software Foundation, either version 3 of the License, or
        (at your option) any later version.

        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU Affero General Public License for more details.

        You should have received a copy of the GNU Affero General Public License
        along with this program.  If not, see <https://www.gnu.org/licenses/>.
        -->
        <title>{{ ganarchy.title|e }}</title>
        <meta name="description" content="{{ ganarchy.title|e }}" />
        <!--if your browser doesn't like the following, use a different browser.-->
        <script type="application/javascript" src="/index.js"></script>
    </head>
    <body>
        <h1>{{ ganarchy.title|e }}</h1>
        <p>This is {{ ganarchy.title|e }}. Currently tracking the following projects:</p>
        <ul>
        {% for project in ganarchy.projects -%}
            <li><a href="/project/{{ project.commit|e }}">{{ project.title|e }}</a>: {{ project.description|e }}</li>
        {% endfor -%}
        </ul>
        <p>Powered by <a href="https://ganarchy.autistic.space/">GAnarchy</a>. AGPLv3-licensed. <a href="https://cybre.tech/SoniEx2/ganarchy">Source Code</a>.</p>
        <p>
            <a href="{{ ganarchy.base_url|e }}" onclick="event.preventDefault(); navigator.registerProtocolHandler('web+ganarchy', this.href + '?url=%s', 'GAnarchy');">Register web+ganarchy: URI handler</a>.
        </p>
    </body>
</html>
""",
            ## project.html FIXME
            'project.html': """<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8" />
        <!--
        GAnarchy - project homepage generator
        Copyright (C) 2019  Soni L.

        This program is free software: you can redistribute it and/or modify
        it under the terms of the GNU Affero General Public License as published by
        the Free Software Foundation, either version 3 of the License, or
        (at your option) any later version.

        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU Affero General Public License for more details.

        You should have received a copy of the GNU Affero General Public License
        along with this program.  If not, see <https://www.gnu.org/licenses/>.
        -->
        <title>{{ project_title|e }}</title>
        {% if project_desc %}<meta name="description" content="{{ project_desc|e }}" />{% endif %}
        <style type="text/css">.branchname { color: #808080; font-style: italic; }</style>
    </head>
    <body>
        <h1>{{ project_title|e }}</h1>
        <p>Tracking <span id="project_commit"><a href="web+ganarchy:{{ project_commit }}">{{ project_commit }}</a></span></p>
        <div id="project_body"><p>{{ project_body|e|replace("\n\n", "</p><p>") }}</p></div>
        <ul>
        {% for url, msg, img, branch in repos -%}
            <li><a href="{{ url|e }}">{{ url|e }}</a>{% if branch %} <span class="branchname">[{{ branch|e }}]</span>{% endif %}: {{ msg|e }}</li>
        {% endfor -%}
        </ul>
        <p>Powered by <a href="https://ganarchy.autistic.space/">GAnarchy</a>. AGPLv3-licensed. <a href="https://cybre.tech/SoniEx2/ganarchy">Source Code</a>.</p>
        <p>
            <a href="/">Main page</a>.
            <a href="{{ base_url|e }}" onclick="event.preventDefault(); navigator.registerProtocolHandler('web+ganarchy', this.href + '?url=%s', 'GAnarchy');">Register web+ganarchy: URI handler</a>.
        </p>
    </body>
</html>
""",
            ## history.svg FIXME
            'history.svg': """""",
        })
    ])


@click.group()
def ganarchy():
    pass

@ganarchy.command()
def initdb():
    """Initializes the ganarchy database."""
    os.makedirs(data_home, exist_ok=True)
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''CREATE TABLE "repos" ("url" TEXT PRIMARY KEY, "active" INT, "branch" TEXT, "project" TEXT)''')
    c.execute('''CREATE UNIQUE INDEX "repos_url_branch_project" ON "repos" ("url", "branch", "project")''')
    c.execute('''CREATE INDEX "repos_project" ON "repos" ("project")''')
    c.execute('''CREATE INDEX "repos_active" ON "repos" ("active")''')
    c.execute('''CREATE TABLE "repo_history" ("entry" INTEGER PRIMARY KEY ASC AUTOINCREMENT, "url" TEXT, "count" INTEGER, "head_commit" TEXT, "branch" TEXT, "project" TEXT)''')
    c.execute('''CREATE INDEX "repo_history_url_branch_project" ON "repo_history" ("url", "branch", "project")''')
    c.execute('''CREATE TABLE "config" ("git_commit" TEXT, "base_url" TEXT, "title" TEXT)''')
    c.execute('''INSERT INTO "config" VALUES ('', '', '')''')
    conn.commit()
    conn.close()

@ganarchy.command()
@click.argument('commit')
def set_commit(commit):
    """Sets the commit that represents the project."""
    if not re.fullmatch("[a-fA-F0-9]{40}", commit):
        raise click.BadArgumentUsage("COMMIT must be a git commit hash")
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''UPDATE "config" SET "git_commit"=?''', (commit,))
    conn.commit()
    conn.close()

@ganarchy.command()
@click.argument('base-url')
def set_base_url(base_url):
    """Sets the GAnarchy instance's base URL. Used for the URI handler."""
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''UPDATE "config" SET "base_url"=?''', (base_url,))
    conn.commit()
    conn.close()

@ganarchy.command()
@click.argument('title')
def set_title(title):
    """Sets the GAnarchy instance's title. This title is displayed on the index."""
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''UPDATE "config" SET "title"=?''', (title,))
    conn.commit()
    conn.close()

# TODO move --branch into here?
@ganarchy.group()
def repo():
    """Modifies repos to track."""

@repo.command()
@click.option('--branch', default=None, help="Sets the branch to be used for the repo")
@click.option('--project', default=None, help="Sets the project commit to be used for the repo")
@click.option('--disabled', default=False, is_flag=True, help="Mark the repo as disabled")
@click.argument('url')
def add(branch, project, disabled, url):
    """Adds a repo to track."""
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''SELECT "git_commit", "base_url" FROM "config"''')
    (project_commit, base_url) = c.fetchone()
    if project_commit == project:
        project = None
    c.execute('''INSERT INTO "repos" ("url", "active", "branch", "project") VALUES (?, ?, ?, ?)''', (url, int(not disabled), branch, project))
    conn.commit()
    conn.close()

@repo.command()
@click.option('--branch', default=None, help="Sets the branch to be used for the repo")
@click.option('--project', default=None, help="Sets the project commit to be used for the repo")
@click.argument('url')
def enable(branch, project, url):
    """Enables tracking of a repo."""
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''SELECT "git_commit", "base_url" FROM "config"''')
    (project_commit, base_url) = c.fetchone()
    if project_commit == project:
        project = None
    c.execute('''UPDATE "repos" SET "active"=1 WHERE "url"=? AND "branch" IS ? AND "project" IS ?''', (url, branch, project))
    conn.commit()
    conn.close()

@repo.command()
@click.option('--branch', default=None, help="Sets the branch to be used for the repo")
@click.option('--project', default=None, help="Sets the project commit to be used for the repo")
@click.argument('url')
def disable(branch, project, url):
    """Disables tracking of a repo."""
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''SELECT "git_commit", "base_url" FROM "config"''')
    (project_commit, base_url) = c.fetchone()
    if project_commit == project:
        project = None
    c.execute('''UPDATE repos SET "active"=0 WHERE "url"=? AND "branch" IS ? AND "project" IS ?''', (url, branch, project))
    conn.commit()
    conn.close()

@repo.command()
@click.option('--branch', default=None, help="Sets the branch to be used for the repo")
@click.option('--project', default=None, help="Sets the project commit to be used for the repo")
@click.argument('url')
def remove(branch, project, url):
    """Stops tracking a repo."""
    click.confirm("WARNING: This operation does not delete the commits associated with the given repo! Are you sure you want to continue? This operation cannot be undone.")
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    c = conn.cursor()
    c.execute('''SELECT "git_commit", "base_url" FROM "config"''')
    (project_commit, base_url) = c.fetchone()
    if project_commit == project:
        project = None
    c.execute('''DELETE FROM "repos" WHERE "url"=? AND "branch" IS ? AND "project" IS ?''', (url, branch, project))
    c.execute('''DELETE FROM "repo_history" WHERE "url"=? AND "branch" IS ? AND "project" IS ?''', (url, branch, project))
    conn.commit()
    conn.close()

def migrations():
    @ganarchy.group()
    def migrations():
        """Modifies the DB to work with a newer/older version.

        WARNING: THIS COMMAND CAN BE EXTREMELY DESTRUCTIVE!"""

    @migrations.command()
    @click.argument('migration')
    def apply(migration):
        """Applies the migration with the given name."""
        conn = sqlite3.connect(data_home + "/ganarchy.db")
        c = conn.cursor()
        click.echo(MIGRATIONS[migration][0])
        for migration in MIGRATIONS[migration][0]:
            c.execute(migration)
        conn.commit()
        conn.close()

    @click.argument('migration')
    @migrations.command()
    def revert(migration):
        """Reverts the migration with the given name."""
        conn = sqlite3.connect(data_home + "/ganarchy.db")
        c = conn.cursor()
        click.echo(MIGRATIONS[migration][1])
        for migration in MIGRATIONS[migration][1]:
            c.execute(migration)
        conn.commit()
        conn.close()

    @click.argument('migration', required=False)
    @migrations.command()
    def info(migration):
        """Shows information about the migration with the given name."""
        if not migration:
            # TODO could be improved
            click.echo(MIGRATIONS.keys())
        else:
            click.echo(MIGRATIONS[migration][2])

migrations()

class GitError(LookupError):
    """Raised when a git operation fails, generally due to a missing commit or branch, or network connection issues."""
    pass

class Repo:
    def __init__(self, dbconn, project, url, branch, list_metadata=False):
        self.url = url
        self.branch = branch
        self.project_commit = project.commit

        if not branch:
            self.branchname = "gan" + hashlib.sha256(url.encode("utf-8")).hexdigest()
            self.head = "HEAD"
        else:
            self.branchname = "gan" + hmac.new(branch.encode("utf-8"), url.encode("utf-8"), "sha256").hexdigest()
            self.head = "refs/heads/" + branch

        try:
            self.hash = subprocess.check_output(["git", "-C", cache_home, "show", self.branchname, "-s", "--format=%H", "--"], stderr=subprocess.DEVNULL).decode("utf-8").strip()
        except subprocess.CalledProcessError:
            self.hash = None

        self.message = None
        if list_metadata:
            try:
                self.fetch_metadata()
            except GitError:
                pass

    def fetch_metadata(self):
        try:
            self.message = subprocess.check_output(["git", "-C", cache_home, "show", self.branchname, "-s", "--format=%B", "--"], stderr=subprocess.DEVNULL).decode("utf-8", "replace")
        except subprocess.CalledProcessError as e:
            raise GitError from e

    def update(self): # FIXME?
        try:
            subprocess.check_output(["git", "-C", cache_home, "fetch", "-q", self.url, "+" + self.head + ":" + self.branchname], stderr=subprocess.STDOUT)
        except subprocess.CalledProcessError as e:
            # This may error for various reasons, but some are important: dead links, etc
            click.echo(e.output, err=True)
            return None
        pre_hash = self.hash
        post_hash = subprocess.check_output(["git", "-C", cache_home, "show", self.branchname, "-s", "--format=%H", "--"], stderr=subprocess.DEVNULL).decode("utf-8").strip()
        self.hash = post_hash
        if not pre_hash:
            pre_hash = post_hash
        try:
            count = int(subprocess.check_output(["git", "-C", cache_home, "rev-list", "--count", pre_hash + ".." + post_hash, "--"]).decode("utf-8").strip())
        except subprocess.CalledProcessError:
            count = 0  # force-pushed
        try:
            subprocess.check_call(["git", "-C", cache_home, "merge-base", "--is-ancestor", self.project_commit, self.branchname], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
            self.fetch_metadata()
            return count, post_hash, self.message
        except (subprocess.CalledProcessError, GitError) as e:
            click.echo(e, err=True)
            return None

class Project:
    def __init__(self, dbconn, ganarchy, project_commit, list_repos=False):
        self.commit = project_commit
        if ganarchy.project_commit == project_commit:
            project_commit = None
        self.refresh_metadata()
        if list_repos:
            repos = []
            with dbconn:
                for (e, url, branch) in dbconn.execute('''SELECT "max"("e"), "url", "branch" FROM (SELECT "max"("T1"."entry") "e", "T1"."url", "T1"."branch" FROM "repo_history" "T1"
                                                                    WHERE (SELECT "active" FROM "repos" "T2" WHERE "url" = "T1"."url" AND "branch" IS "T1"."branch" AND "project" IS ?1)
                                                                    GROUP BY "T1"."url", "T1"."branch"
                                                                    UNION
                                                                    SELECT null, "T3"."url", "T3"."branch" FROM "repos" "T3" WHERE "active" AND "project" IS ?1)
                                           GROUP BY "url" ORDER BY "e"''', (project_commit,)):
                    repos.append(Repo(dbconn, self, url, branch))
            self.repos = repos
        else:
            self.repos = None

    def refresh_metadata(self):
        try:
            project = subprocess.check_output(["git", "-C", cache_home, "show", self.commit, "-s", "--format=%B", "--"], stderr=subprocess.DEVNULL).decode("utf-8", "replace")
            project_title, project_desc = (lambda x: x.groups() if x is not None else ('', None))(re.fullmatch('^\\[Project\\]\s+(.+?)(?:\n\n(.+))?$', project, flags=re.ASCII|re.DOTALL|re.IGNORECASE))
            if not project_title.strip():
                project_title, project_desc = ("Error parsing project commit",)*2
            if project_desc:
                project_desc = project_desc.strip()
            self.commit_body = project
            self.title = project_title
            self.description = project_desc
        except subprocess.CalledProcessError:
            self.commit_body = None
            self.title = None
            self.description = None

    def update(self):
        # TODO
        self.refresh_metadata()

class GAnarchy:
    def __init__(self, dbconn, list_projects=False):
        with dbconn:
            # TODO
            #(project_commit, base_url, title) = dbconn.execute('''SELECT "git_commit", "base_url", "title" FROM "config"''').fetchone()
            (project_commit, base_url) = dbconn.execute('''SELECT "git_commit", "base_url" FROM "config"''').fetchone()
            title = None
            self.project_commit = project_commit
            self.base_url = base_url
            if not base_url:
                pass ## TODO
            if not title:
                from urllib.parse import urlparse
                title = "GAnarchy on " + urlparse(base_url).hostname
            self.title = title
        if list_projects:
            projects = []
            with dbconn:
                for (project,) in dbconn.execute('''SELECT DISTINCT "project" FROM "repos" '''): # FIXME? *maybe* sort by activity in the future
                    if project == None:
                        project = self.project_commit
                    projects.append(Project(dbconn, ganarchy, project))
            projects.sort(key=lambda project: project.title)
            self.projects = projects
        else:
            self.projects = None


@ganarchy.command()
@click.argument('project', required=False)
def cron_target(project):
    """Runs ganarchy as a cron target."""
    # make sure the cache dir exists
    os.makedirs(cache_home, exist_ok=True)
    # make sure it is a git repo
    subprocess.call(["git", "-C", cache_home, "init", "-q"])
    conn = sqlite3.connect(data_home + "/ganarchy.db")
    instance = GAnarchy(conn, list_projects=project=="index")
    env = jinja2.Environment(loader=get_template_loader(), autoescape=False)
    if project == "index":
        # render the index
        template = env.get_template('index.html')
        click.echo(template.render(ganarchy = instance))
        return
    project_commit = instance.project_commit
    base_url = instance.base_url
    if not base_url or not (project or project_commit):
        click.echo("No base URL or project commit specified", err=True)
        return
    if project_commit == project:
        project = None
    elif project is not None:
        project_commit = project
    entries = []
    generate_html = []
    c = conn.cursor()
    p = Project(conn, instance, project_commit, list_repos=True)
    # FIXME: this should be moved into Project.update()
    for repo in p.repos:
        result = repo.update()
        if result is not None:
            count, post_hash, msg = result
            entries.append((repo.url, count, post_hash, repo.branch, project))
            generate_html.append((repo.url, msg, count, repo.branch))
    p.refresh_metadata()
    # sort stuff twice because reasons
    entries.sort(key=lambda x: x[1], reverse=True)
    generate_html.sort(key=lambda x: x[2], reverse=True)
    c.executemany('''INSERT INTO "repo_history" ("url", "count", "head_commit", "branch", "project") VALUES (?, ?, ?, ?, ?)''', entries)
    conn.commit()
    html_entries = []
    for (url, msg, count, branch) in generate_html:
        history = c.execute('''SELECT "count" FROM "repo_history" WHERE "url" = ? AND "branch" IS ? AND "project" IS ? ORDER BY "entry" ASC''', (url, branch, project)).fetchall()
        # TODO process history into SVG
        html_entries.append((url, msg, "", branch))
    template = env.get_template('project.html')
    click.echo(template.render(project_title  = p.title,
                               project_desc   = p.description,
                               project_body   = p.commit_body,
                               project_commit = p.commit,
                               repos          = html_entries,
                               base_url       = base_url,
                               # I don't think this thing supports deprecating the above?
                               project        = p,
                               ganarchy       = instance))

if __name__ == "__main__":
    ganarchy()