import json
import os
import subprocess
from datetime import datetime

from db import db, Job, Run


BACKUP_DIR = None  # initialisé depuis app.config


def execute_job(job_id):
    """Point d'entrée appelé par APScheduler (dans app_context Flask)."""
    from flask import current_app
    backup_dir = current_app.config["YUNOHOST_BACKUP_DIR"]
    instance = current_app.config["INSTANCE_NAME"]

    job = db.session.get(Job, job_id)
    if not job or not job.enabled:
        return

    run = Run(job_id=job_id, started_at=datetime.utcnow(), status="running")
    db.session.add(run)
    db.session.commit()

    try:
        if job.type == "ynh_app":
            archive_name, log = _run_ynh_app(job, instance, backup_dir)
        elif job.type == "ynh_system":
            archive_name, log = _run_ynh_system(job, instance, backup_dir)
        elif job.type in ("mysql", "postgresql"):
            from jobs.db_dump import run_db_dump
            archive_name, log = run_db_dump(job, instance, backup_dir)
        elif job.type == "custom_dir":
            from jobs.custom_dir import backup_custom_dir
            archive_name, log = backup_custom_dir(job, instance, backup_dir)
        else:
            raise ValueError(f"Type de job non géré : {job.type}")

        archive_path = os.path.join(backup_dir, archive_name + ".tar")
        from jobs.utils import sudo_getsize
        size_bytes = sudo_getsize(archive_path) or None

        run.status = "success"
        run.archive_name = archive_name
        run.size_bytes = size_bytes
        run.log_text = log

        from retention import apply_retention
        deleted = apply_retention(job, archive_name, backup_dir)
        if deleted:
            run.log_text += f"\n\nRétention : {len(deleted)} archive(s) supprimée(s) : {', '.join(deleted)}"

        # Transfert automatique vers la destination configurée
        if job.destination_id:
            from db import Destination
            from flask import current_app
            dest = db.session.get(Destination, job.destination_id)
            if dest and dest.enabled:
                data_dir = current_app.config["DATA_DIR"]
                try:
                    from jobs.transfer import transfer_archive
                    transfer_log = transfer_archive(archive_name, dest, backup_dir, data_dir)
                    run.log_text += f"\n\nTransfert → {dest.remote_str} :\n{transfer_log}"
                except Exception as transfer_exc:
                    run.log_text += f"\n\n⚠ Transfert échoué vers {dest.remote_str} :\n{transfer_exc}"

    except Exception as exc:
        run.status = "error"
        run.log_text = str(exc)

    finally:
        run.finished_at = datetime.utcnow()
        db.session.commit()

    try:
        from notifications import send_job_notification
        send_job_notification(run, job)
    except Exception:
        pass


def _archive_name(instance, label):
    date_str = datetime.utcnow().strftime("%Y%m%d")
    return f"{instance}_{label}_{date_str}"


def _run_ynh_app(job, instance, backup_dir):
    cfg = json.loads(job.config_json or "{}")
    app_id = cfg.get("app_id", "")
    core_only = cfg.get("core_only", job.core_only)

    archive = _archive_name(instance, app_id)
    _abort_if_exists(archive, backup_dir)

    cmd = ["sudo", "yunohost", "backup", "create", "--apps", app_id, "--name", archive]
    if core_only:
        cmd = ["sudo", "env", "BACKUP_CORE_ONLY=1"] + cmd[1:]

    result = subprocess.run(cmd, capture_output=True, text=True, timeout=3600)
    log = (result.stdout + result.stderr).strip()

    if result.returncode != 0:
        raise RuntimeError(f"yunohost backup create a échoué (code {result.returncode}) :\n{log}")

    return archive, log


def _run_ynh_system(job, instance, backup_dir):
    archive = _archive_name(instance, "system")
    _abort_if_exists(archive, backup_dir)

    cmd = ["sudo", "yunohost", "backup", "create", "--system", "--name", archive]
    result = subprocess.run(cmd, capture_output=True, text=True, timeout=3600)
    log = (result.stdout + result.stderr).strip()

    if result.returncode != 0:
        raise RuntimeError(f"yunohost backup create a échoué (code {result.returncode}) :\n{log}")

    return archive, log


def _abort_if_exists(archive_name, backup_dir):
    path = os.path.join(backup_dir, archive_name + ".tar")
    if os.path.exists(path):
        raise RuntimeError(
            f"L'archive {archive_name}.tar existe déjà. "
            "Supprimez-la manuellement ou attendez le prochain cycle."
        )