# modules/common/boot_notice.py
import os
import re
import base64
import json
import time
from datetime import datetime, timezone
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 versions like 1.2.3.4.a2 (last segment may be alnum).
    Returns -1 if a<b, 0 if equal/unknown, +1 if a>b.
    If either is None, treat as equal to avoid false positives.
    """
    if not a or not b:
        return 0
    pa = a.split('.')
    pb = b.split('.')
    while len(pa) < 5: pa.append('0')
    while len(pb) < 5: pb.append('0')

    def part_key(x: str):
        if x.isdigit():
            return (int(x), '', 1)
        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
        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]}")
            # Gitea returns either dict or list depending on endpoint
            ctype = resp.headers.get("Content-Type", "")
            if "application/json" not in ctype:
                text = await resp.text()
                raise RuntimeError(f"Gitea GET {url} non-JSON: {ctype} {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 using the
    list-commits endpoint which includes the full commit message:
      /api/v1/repos/{owner}/{repo}/commits?sha={branch}&limit=1&stat=false&verification=false&files=false
    """
    url = (
        f"{api_base}/repos/{owner}/{repo}/commits"
        f"?sha={branch}&limit=1&stat=false&verification=false&files=false"
    )
    data = await _gitea_get_json(url, token, user)
    if not isinstance(data, list) or not data:
        raise RuntimeError("Commits list empty or invalid.")
    latest = data[0]
    sha = latest.get("sha") or latest.get("id")
    message = ""
    commit_obj = latest.get("commit") or {}
    if isinstance(commit_obj, dict):
        message = commit_obj.get("message") or ""
    if not message:
        # Extremely unlikely on this endpoint, but try secondary fetch
        if sha:
            for endpoint in (
                f"{api_base}/repos/{owner}/{repo}/git/commits/{sha}",
                f"{api_base}/repos/{owner}/{repo}/commits/{sha}",
            ):
                try:
                    det = await _gitea_get_json(endpoint, token, user)
                    if isinstance(det, dict):
                        m = det.get("message") or det.get("commit", {}).get("message")
                        if m:
                            message = str(m)
                            break
                except Exception:
                    continue
    subject, body = _split_subject_body(message)
    return sha, (subject or ""), (body or "")

# ---------------- 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.
      - Waits for ready.
      - Infers reason (updated/scheduled/manual/rollback).
      - Fetches latest commit (full message) via list-commits endpoint.
      - Posts status + commit message (Version bold + md details).
      - Pings guild owner only on rollback.
      - Persists last sha/version in data_manager['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:
        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')
    check_time_utc = r.get('check_time_utc', '')  # e.g., "03:00"
    now_utc = datetime.now(timezone.utc)

    api_base = owner = repo = None
    if repo_url:
        api_base, owner, repo = _parse_repo_url(repo_url)
    else:
        print("[boot_notice] repo_url missing; commit lookup skipped.")

    token = os.getenv("SHAI_GITEA_TOKEN", "").strip() or None
    user  = os.getenv("SHAI_GITEA_USER", "").strip() or None

    # State
    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}")
    else:
        print("[boot_notice] repo parsing failed; commit lookup skipped.")

    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:
            reason = "scheduled" if _is_near_scheduled(now_utc, check_time_utc) else "manual"
    else:
        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:
        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 (Version + md details)
    try:
        title = curr_ver or (subject or "Latest commit")
        if title or body:
            commit_msg = f"**{title}**\n{body}" if body else 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 state
    try:
        new_state = {
            'last_sha': sha,
            'last_version': curr_ver,
            'last_subject': subject,
            'last_boot_ts': time.time(),
        }
        dm.add('boot_state', new_state)
    except Exception as e:
        print(f"[boot_notice] failed to persist boot_state: {e}")