"""Healthcheck endpoint - GMAO Collège"""
from flask import Blueprint, jsonify
from app_new.extensions import db
from app_new.core.models import User
from app_new.version import get_version
import subprocess
import os
import time
from datetime import datetime

health_bp = Blueprint('health', __name__, url_prefix='/health')


# Constantes
WATCHDOG_STARTUP_GRACE_SECONDS = 60
APP_START_TIME = time.time()


def _check_watchdog(name, start_time_threshold=None):
    """Verifie si un processus watchdog tourne via /proc."""
    try:
        pids = []
        for pid in os.listdir('/proc'):
            if not pid.isdigit():
                continue
            try:
                cmdline_path = f'/proc/{pid}/cmdline'
                with open(cmdline_path, 'rb') as f:
                    cmdline = f.read().decode('utf-8', errors='replace').replace('\x00', ' ')
                if name in cmdline and 'grep' not in cmdline:
                    pids.append(int(pid))
            except (FileNotFoundError, PermissionError):
                continue
        if pids:
            return {'running': True, 'pid': pids[0], 'instances': len(pids)}
        # Grace period au demarrage
        if start_time_threshold and time.time() - APP_START_TIME < start_time_threshold:
            return {'running': False, 'starting': True}
        return {'running': False}
    except Exception as e:
        return {'running': False, 'error': str(e)}


def _check_database():
    """Verifie la connexion a la base de donnees."""
    try:
        db.session.execute(db.text('SELECT 1'))
        return {'connected': True, 'dialect': str(db.engine.url).split('://')[0]}
    except Exception as e:
        return {'connected': False, 'error': str(e)}


@health_bp.route('/')
def health():
    """Endpoint public de healthcheck."""
    db_status = _check_database()

    # Le watchdog pronote met parfois plus de temps a demarrer (connexion ENT)
    watchdogs = {
        'flask': _check_watchdog('gunicorn'),
        'gmao_watchdog': _check_watchdog('gmao_watchdog.py'),
        'ent_watchdog': _check_watchdog('ent_watchdog.py'),
        'pronote_watchdog': _check_watchdog('pronote_watchdog.py', start_time_threshold=WATCHDOG_STARTUP_GRACE_SECONDS),
        'watchdog_dnd': _check_watchdog('watchdog_dnd.py'),
    }

    all_watchdogs_ok = all(
        w.get('running') or w.get('starting')
        for w in watchdogs.values()
    )
    healthy = db_status.get('connected') and all_watchdogs_ok and not any(w.get('starting') for w in watchdogs.values())

    git_commit = 'unknown'
    try:
        result = subprocess.run(
            ['git', '-C', '/app', 'rev-parse', '--short', 'HEAD'],
            capture_output=True,
            text=True,
            timeout=5
        )
        if result.returncode == 0:
            git_commit = result.stdout.strip()
    except Exception:
        pass
    
    # Fallback si git n'est pas disponible dans l'image
    if git_commit == 'unknown':
        version_file = '/app/.git-version'
        if os.path.exists(version_file):
            try:
                with open(version_file) as f:
                    git_commit = f.read().strip()
            except Exception:
                pass

    response = {
        'status': 'healthy' if healthy else 'degraded',
        'version': get_version(),
        'timestamp': datetime.utcnow().isoformat() + 'Z',
        'database': db_status,
        'watchdogs': watchdogs,
        'git_commit': git_commit,
        'environment': os.environ.get('FLASK_ENV', 'production'),
        'uptime_seconds': int(time.time() - APP_START_TIME)
    }
    return jsonify(response), 200 if healthy else 503