import subprocess
import asyncio

import lightbulb
import hikari

from lib.config import load_config

config = load_config()

plugin = lightbulb.Plugin("SystemPlugin")

async def create_subprocess(*args):
    proc = await asyncio.create_subprocess_exec(*args,
        stdout=asyncio.subprocess.PIPE,
        stderr=asyncio.subprocess.PIPE
    )
    stdout, _ = await proc.communicate()
    return stdout.decode("utf-8").strip()

async def get_git_latest_commit_id():
    return await create_subprocess("git", "rev-parse", "--short", "HEAD")

async def get_git_branch():
    return await create_subprocess("git", "rev-parse", "--abbrev-ref", "HEAD")

async def get_git_remote():
    return await create_subprocess("git", "branch", "-r")

async def get_git_head_diff_branch(branch: str) -> str:
    # diff HEAD to remote
    return await create_subprocess("git", "diff", "head", branch)

async def get_git_index_diff_branch(branch: str) -> str:
    # diff index to remote
    return await create_subprocess("git", "diff", branch)

async def get_git_commits_ahead_behind(branch: str, remote: str) -> tuple[int, int]:
    # commits ahead/behind remote
    output = await create_subprocess("git", "rev-list", "--left-right", "--count", branch+"..."+remote)
    commits_ahead = int(output.split()[0])
    commits_behind = int(output.split()[1])
    return commits_ahead, commits_behind

async def get_git_dev(remote: str, branch: str) -> bool:
    # dev environment tests
    if await get_git_head_diff_branch(remote) != "":  # difference between HEAD and remote
        return True
    elif config.git_branch != branch:  # branch has been changed
        return True
    elif await get_git_index_diff_branch(remote) != "":  # difference between index and remote
        return True
    elif (await get_git_commits_ahead_behind(branch, remote))[0] > 0:  # ahead in commits
        return True
    return False

async def get_git_update(dev_status: bool, branch, remote) -> bool:
    commits_behind, _ = await get_git_commits_ahead_behind(branch, remote)
    if not dev_status and commits_behind > 0:
        return True
    return False

async def get_git_status() -> dict:
    output = {}
    output["commit_id"] = await get_git_latest_commit_id()
    output["branch"] = await get_git_branch()
    output["remote"] = await get_git_remote()
    output["dev"] = await get_git_dev(output['remote'], output['branch'])
    output['update'] = await get_git_update(output['dev'], output['branch'], output['remote'])
    return output

@plugin.command
@lightbulb.command("ping", "pong!", ephemeral=True)
@lightbulb.implements(lightbulb.SlashCommand)
async def ping(ctx: lightbulb.Context) -> None:
    embed = hikari.Embed(title="Pong!",
        description=f"latency: {round(ctx.bot.heartbeat_latency * 1000, ndigits=2)}ms"
    )
    await ctx.respond(embed)

@plugin.command
@lightbulb.add_checks(lightbulb.owner_only)
@lightbulb.command("update", "update the bot!", ephemeral=True)
@lightbulb.implements(lightbulb.SlashCommand)
async def update(ctx: lightbulb.Context) -> None:
    if (await get_git_status())['dev'] is False:
        await create_subprocess("git", "pull")
    embed = hikari.Embed(title="Restarting",
        description="Restarting to load an update!"
    )
    await ctx.respond(embed)
    await ctx.bot.close()

@plugin.command
@lightbulb.command("info", "get bot information such as the version, and repository link.", ephemeral=True)
@lightbulb.implements(lightbulb.SlashCommand)
async def info(ctx: lightbulb.Context) -> None:
    git_status = await get_git_status()
    embed = hikari.Embed(title="About Me!")
    embed.add_field("Git Repository", config.git_url)
    embed.add_field("Version", git_status['commit_id'], inline=True)
    embed.add_field("Branch", git_status['branch'], inline=True)
    embed.add_field("Remote", git_status['remote'], inline=True)
    embed.add_field("In Dev-Env?", git_status['dev'])
    embed.add_field("Needs Update?", git_status['update'])
    await ctx.respond(embed)

def load(bot: lightbulb.BotApp):
    bot.add_plugin(plugin)

def unload(bot: lightbulb.BotApp):
    bot.remove_plugin(plugin)