#!/usr/bin/env python3

"""
Auto-generates documentation from command defs in console.py.
"""

import html
import os
import re
import shutil
import textwrap

from twitchdl.console import COMMANDS


START_MARKER = "<!-- ------------------- generated docs start ------------------- -->"
END_MARKER = "<!-- ------------------- generated docs end ------------------- -->"


def main():
    update_changelog()
    for command in COMMANDS:
        update_docs(command)


def update_changelog():
    print("Updating: docs/changelog.md")
    root = os.path.realpath(os.path.dirname(os.path.dirname(__file__)))
    source = os.path.join(root, "CHANGELOG.md")
    target = os.path.join(root, "docs/changelog.md")
    shutil.copy(source, target)


def update_docs(command):
    path = os.path.join("docs", "commands", f"{command.name}.md")
    content = render_command(command)

    if not os.path.exists(path):
        print(f"Creating: {path}")
        write(path, content)
    else:
        print(f"Updating: {path}")
        [_, handwritten] = read(path).split(END_MARKER)
        content = f"{content.strip()}\n\n{END_MARKER}\n\n{handwritten.strip()}"
        write(path, content)


def render_command(command):
    content = START_MARKER
    content += f"\n# twitch-dl {command.name}\n\n"
    content += command.description + "\n\n"
    content += render_usage(command)
    content += render_arguments(command)
    content += render_flags(command)
    content += render_options(command)
    return content


def render_usage(command):
    arguments = get_arguments(command)
    arguments = " ".join(f"<{name}>" for [name, _] in arguments)
    flags = get_flags(command)
    options = get_options(command)

    content = "### USAGE\n\n"
    content += "```\n"
    content += f"twitch-dl {command.name} {arguments}"

    if flags:
        content += " [FLAGS]"

    if options:
        content += " [OPTIONS]"

    content += "\n```\n\n"

    return content


def render_arguments(command):
    arguments = get_arguments(command)

    if not arguments:
        return ""

    content = "### ARGUMENTS\n\n"

    content += "<table>\n"
    content += "<tbody>"
    for [name, params] in arguments:
        content += textwrap.dedent(f"""
        <tr>
            <td class="code">&lt;{escape(name)}&gt;</td>
            <td>{escape(params['help'])}</td>
        </tr>
        """)
    content += "</tbody>\n"
    content += "</table>\n\n"

    return content


def render_flags(command):
    flags = get_flags(command)

    if not flags:
        return ""

    content = "### FLAGS\n\n"

    content += "<table>\n"
    content += "<tbody>"
    for [names, params] in flags:
        names = ", ".join(f"{name}" for name in names)
        content += textwrap.dedent(f"""
        <tr>
            <td class="code">{escape(names)}</td>
            <td>{escape(params['help'])}</td>
        </tr>
        """)
    content += "</tbody>\n"
    content += "</table>\n\n"

    return content


def render_options(command):
    options = get_options(command)

    if not options:
        return ""

    content = "### OPTIONS\n\n"

    content += "<table>\n"
    content += "<tbody>"
    for [names, params] in options:
        names = ", ".join(f"{name}" for name in names)
        content += textwrap.dedent(f"""
        <tr>
            <td class="code">{escape(names)}</td>
            <td>{escape(params['help'])}{choices(params)}</td>
        </tr>
        """)
    content += "</tbody>\n"
    content += "</table>\n\n"

    return content


def choices(params):
    if "choices" in params:
        choices = ", ".join(code(c) for c in params["choices"])
        return f" Possible values: {choices}."
    return ""


def get_arguments(command):
    return [
        [names[0], options]
        for names, options in command.arguments
        if len(names) == 1 and not names[0].startswith("-")
    ]


def get_flags(command):
    return [
        [names, options]
        for names, options in command.arguments
        if names[0].startswith("-") and "type" not in options
    ]


def get_options(command):
    return [
        [names, options]
        for names, options in command.arguments
        if names[0].startswith("-") and "type" in options
    ]


def read(path):
    with open(path, "r") as f:
        return f.read()


def write(path, content):
    with open(path, "w") as f:
        return f.write(content)


def code(string):
    return f"<code>{string}</code>"


def escape(text: str):
    text = html.escape(text)
    text = re.sub(r"`([\S]+)`", "<code>\\1</code>", text)
    return text


if __name__ == "__main__":
    main()