# modules/common/boot_notice.py
import os
import re
import base64
import json
import time
from datetime import datetime, timezone, timedelta
from urllib.parse import urlparse

import discord
import aiohttp

from modules.common.settings import cfg

# ---------------- Version helpers ----------------

_VERSION_RE = re.compile(r'\b\d+\.\d+\.\d+\.\d+(?:\.[A-Za-z0-9]+)?\b')

def _extract_version(subject: str) -> str | None:
    if not subject:
        return None
    m = _VERSION_RE.search(subject)
    return m.group(0) if m else None

def _split_subject_body(full_message: str) -> tuple[str | None, str | None]:
    if not full_message:
        return None, None
    lines = [ln.rstrip() for ln in full_message.splitlines()]
    # subject = first non-empty line
    subject = None
    i = 0
    while i < len(lines) and subject is None:
        if lines[i].strip():
            subject = lines[i].strip()
        i += 1
    body = '\n'.join(lines[i:]).strip() if i < len(lines) else ''
    return subject or None, (body or None)

def _cmp_versions(a: str | None, b: str | None) -> int:
    """
    Compare your version style: 1.2.3.4.a2 (last segment alnum optional).
    Returns: -1 if a<b, 0 if equal/unknown, +1 if a>b.
    If either is None, treat as equal (0) to avoid false rollback/upgrade.
    """
    if not a or not b:
        return 0
    pa = a.split('.')
    pb = b.split('.')
    # pad to 5 parts
    while len(pa) < 5: pa.append('0')
    while len(pb) < 5: pb.append('0')

    def part_key(x: str):
        # numeric if digits; else (numeric_prefix, alpha_suffix)
        if x.isdigit():
            return (int(x), '', 1)
        # split alnum: digits prefix (if any) + rest
        m = re.match(r'(\d+)(.*)', x)
        if m:
            return (int(m.group(1)), m.group(2), 2)
        return (0, x, 3)

    for xa, xb in zip(pa, pb):
        ka, kb = part_key(xa), part_key(xb)
        if ka[0] != kb[0]:
            return 1 if ka[0] > kb[0] else -1
        if ka[2] != kb[2]:
            return 1 if ka[2] < kb[2] else -1  # prefer pure numeric (1) > num+alpha (2) > alpha (3)
        if ka[1] != kb[1]:
            return 1 if ka[1] > kb[1] else -1
    return 0

# ---------------- Gitea helpers ----------------

def _parse_repo_url(repo_url: str) -> tuple[str | None, str | None, str | None]:
    """
    From https://host/owner/repo(.git) -> (api_base, owner, repo)
    api_base = https://host/api/v1
    """
    try:
        pr = urlparse(repo_url)
        parts = [p for p in pr.path.split('/') if p]
        if len(parts) >= 2:
            owner = parts[0]
            repo = parts[1]
            if repo.endswith('.git'):
                repo = repo[:-4]
            api_base = f"{pr.scheme}://{pr.netloc}/api/v1"
            return api_base, owner, repo
    except Exception:
        pass
    return None, None, None

async def _gitea_get_json(url: str, token: str | None, user: str | None, timeout_sec: int = 10):
    headers = {}
    if token and user:
        # Basic auth with user:token
        cred = base64.b64encode(f"{user}:{token}".encode()).decode()
        headers['Authorization'] = f"Basic {cred}"
    elif token:
        headers['Authorization'] = f"token {token}"

    timeout = aiohttp.ClientTimeout(total=timeout_sec)
    async with aiohttp.ClientSession(timeout=timeout, headers=headers) as sess:
        async with sess.get(url) as resp:
            if resp.status != 200:
                text = await resp.text()
                raise RuntimeError(f"Gitea GET {url} -> {resp.status}: {text[:200]}")
            return await resp.json()

async def _fetch_latest_commit(api_base: str, owner: str, repo: str, branch: str,
                               token: str | None, user: str | None) -> tuple[str | None, str | None, str | None]:
    """
    Returns (sha, subject, body) for the latest commit on branch.
    """
    # Fast path: get branch -> commit sha
    branch_url = f"{api_base}/repos/{owner}/{repo}/branches/{branch}"
    try:
        bjson = await _gitea_get_json(branch_url, token, user)
        sha = bjson.get('commit', {}).get('id') or bjson.get('commit', {}).get('sha')
        if not sha:
            raise RuntimeError("No commit sha on branch")
    except Exception as e:
        # Fallback: list commits
        commits_url = f"{api_base}/repos/{owner}/{repo}/commits/{branch}"
        try:
            cjson = await _gitea_get_json(commits_url, token, user)
            if isinstance(cjson, list) and cjson:
                sha = cjson[0].get('sha') or cjson[0].get('id')
            else:
                raise RuntimeError("Empty commits list")
        except Exception as e2:
            raise RuntimeError(f"Failed to get latest commit: {e} / {e2}")

    # Now fetch full commit message
    # Try git/commits first
    for endpoint in (f"{api_base}/repos/{owner}/{repo}/git/commits/{sha}",
                     f"{api_base}/repos/{owner}/{repo}/commits/{sha}"):
        try:
            data = await _gitea_get_json(endpoint, token, user)
            msg = None
            if isinstance(data, dict):
                msg = data.get('message')
                if not msg:
                    msg = data.get('commit', {}).get('message')
            subject, body = _split_subject_body(msg or "")
            return sha, (subject or ""), (body or "")
        except Exception:
            continue
    raise RuntimeError("Unable to fetch commit details")

# ---------------- Boot reason inference ----------------

def _is_near_scheduled(now_utc: datetime, hhmm_utc: str | None, window_min: int = 5) -> bool:
    if not hhmm_utc:
        return False
    try:
        hh, mm = [int(x) for x in hhmm_utc.strip().split(':', 1)]
    except Exception:
        return False
    sched = now_utc.replace(hour=hh, minute=mm, second=0, microsecond=0)
    delta = abs((now_utc - sched).total_seconds())
    return delta <= window_min * 60

def _format_status_line(kind: str, old_ver: str | None, new_ver: str | None) -> str:
    if kind == "updated":
        return f"✅ Updated from **{old_ver or 'unknown'}** → **{new_ver or 'unknown'}**"
    if kind == "scheduled":
        return "🕒 Scheduled restart executed"
    if kind == "manual":
        return "🟢 Manual restart detected"
    if kind == "rollback":
        return f"⚠️ Version rollback detected: **{old_ver or 'unknown'}** → **{new_ver or 'unknown'}**"
    return "🟢 Bot started"

# ---------------- Main entry ----------------

async def post_boot_notice(bot):
    """
    Always post a boot status to the modlog channel.
    Logic:
      - Wait until bot is ready (guilds/channels cached).
      - Resolve repo from cfg(repo_url/repo_branch); attempt to fetch latest commit (sha, subject, body).
      - Compare to stored boot_state (last_sha/last_version/last_boot_ts):
          * sha/version advanced -> Updated
          * sha same and near scheduled time -> Scheduled restart
          * sha same and not near schedule -> Manual restart
          * version decreased -> Rollback (ping guild owner)
      - Post status line.
      - Post commit message (bold version + md body).
      - Persist new boot_state.
    """
    try:
        await bot.wait_until_ready()
    except Exception as e:
        print(f"[boot_notice] wait_until_ready failed: {e}")

    # Resolve modlog channel
    modlog_channel_id = cfg(bot).int('modlog_channel_id', 0)
    if not modlog_channel_id:
        print("[boot_notice] modlog_channel_id not configured; skipping.")
        return

    ch = bot.get_channel(modlog_channel_id)
    if not ch:
        # fallback: search across guilds
        for g in bot.guilds:
            ch = g.get_channel(modlog_channel_id)
            if ch:
                break
    if not ch:
        print(f"[boot_notice] channel id {modlog_channel_id} not found; skipping.")
        return

    # Repo info
    r = cfg(bot)
    repo_url = r.get('repo_url', '')
    branch = r.get('repo_branch', 'main')
    api_base = owner = repo = None

    if repo_url:
        api_base, owner, repo = _parse_repo_url(repo_url)

    token = os.getenv("SHAI_GITEA_TOKEN", "").strip() or None
    user  = os.getenv("SHAI_GITEA_USER", "").strip() or None
    check_time_utc = r.get('check_time_utc', '')  # e.g., "03:00"
    now_utc = datetime.now(timezone.utc)

    # State store
    dm = getattr(bot, "data_manager", None)
    if not dm:
        print("[boot_notice] data_manager missing on bot; cannot persist state.")
        return

    prev = (dm.get('boot_state') or [{}])[-1] if dm.get('boot_state') else {}
    prev_sha = prev.get('last_sha') or None
    prev_ver = prev.get('last_version') or None

    # Fetch latest commit (sha, subject, body)
    sha = subject = body = None
    if api_base and owner and repo:
        try:
            sha, subject, body = await _fetch_latest_commit(api_base, owner, repo, branch, token, user)
        except Exception as e:
            print(f"[boot_notice] fetch latest commit failed: {e}")

    # Derive current version (from subject)
    curr_ver = _extract_version(subject) if subject else None

    # Decide reason
    reason = "manual"
    mention_owner = False

    if prev_ver and curr_ver:
        cmpv = _cmp_versions(prev_ver, curr_ver)
        if cmpv < 0:
            reason = "updated"
        elif cmpv > 0:
            reason = "rollback"
            mention_owner = True
        else:  # same version
            reason = "scheduled" if _is_near_scheduled(now_utc, check_time_utc) else "manual"
    else:
        # Fall back to sha compare if versions missing
        if prev_sha and sha and prev_sha != sha:
            reason = "updated"
        else:
            reason = "scheduled" if _is_near_scheduled(now_utc, check_time_utc) else "manual"

    # Post status line
    status_line = _format_status_line(reason, prev_ver, curr_ver)
    try:
        # ping owner only on rollback
        allowed = discord.AllowedMentions(everyone=False, users=True if mention_owner else False, roles=False, replied_user=False)
        if mention_owner and ch.guild and ch.guild.owner_id:
            status_line = f"{status_line}\n<@{ch.guild.owner_id}>"
        await ch.send(status_line, allowed_mentions=allowed)
    except Exception as e:
        print(f"[boot_notice] failed to send status line: {e}")
        return

    # Post commit message (if we have it)
    # Format: **Version**\n<md body>
    try:
        title = curr_ver or (subject or "Latest commit")
        if title or body:
            # Always post a commit message on start; it’s the core “what’s running now”
            if body:
                commit_msg = f"**{title}**\n{body}"
            else:
                commit_msg = f"**{title}**"
            await ch.send(commit_msg, allowed_mentions=discord.AllowedMentions.none())
    except Exception as e:
        print(f"[boot_notice] failed to send commit message: {e}")

    # Persist new state
    try:
        new_state = {
            'last_sha': sha,
            'last_version': curr_ver,
            'last_subject': subject,
            'last_boot_ts': time.time(),
        }
        # keep boot_state as list to preserve history
        dm.add('boot_state', new_state)
    except Exception as e:
        print(f"[boot_notice] failed to persist boot_state: {e}")