"""System health endpoints (ROADMAP #85, tranche 1).

Handlers déplacés depuis :mod:`backend.main` sans changement de
comportement : mêmes chemins (``/api/health``, ``/api/health/detailed``),
même ``response_model`` (:class:`backend.schemas.HealthResponse`), même
dépendance admin. Seule différence : la version est lue via
:func:`backend.version.get_version` au lieu de ``app.version`` (valeur
identique, figée au démarrage depuis le fichier ``VERSION``).

Note : ``uptime_seconds`` reprend l'expression d'origine
(``'_SERVER_START_TIME' in globals()``), qui vaut toujours 0 — le global
n'est défini nulle part dans ``backend.main`` (voir ``backend.admin`` qui
possède son propre compteur). Ce comportement est préservé tel quel ; le
corriger fera l'objet d'une tranche ultérieure avec test dédié.
"""

from fastapi import APIRouter, Depends

from backend.auth.middleware import require_admin
from backend.indexer import index
from backend.schemas import HealthResponse
from backend.version import get_git_commit, get_git_describe, get_version

router = APIRouter(tags=["System"])


@router.get("/api/health", response_model=HealthResponse)
async def api_health():
    """Health check endpoint for Docker and monitoring.

    Returns:
        Application status, version, vault count and total file count.
    """
    total_files = sum(len(v["files"]) for v in index.values())
    total_tokens = sum(len(v.get("files", [])) * 1000 for v in index.values())  # rough approx
    import time

    from backend.indexer import _last_full_index_ts
    # `_SERVER_START_TIME` n'existe dans aucun module (comportement d'origine
    # préservé : uptime toujours 0 — voir docstring du module).
    uptime = int(time.time() - _SERVER_START_TIME) if '_SERVER_START_TIME' in globals() else 0  # noqa: F821
    return {
        "status": "ok",
        "version": get_version(),
        "vaults": len(index),
        "total_files": total_files,
        "total_tokens": total_tokens,
        "last_full_index_ts": _last_full_index_ts,
        "uptime_seconds": uptime,
        "git_describe": get_git_describe(),
        "git_commit": get_git_commit(),
    }


@router.get("/api/health/detailed", response_model=HealthResponse)
async def api_health_detailed(current_user=Depends(require_admin)):
    """Detailed health check — admin only.

    Returns enriched metrics including memory, disk, SSE connections, and backup stats.
    """

    import psutil

    from backend.admin import _count_active_sessions, _get_disk_stats
    from backend.indexer import _last_full_index_ts, index

    total_files = sum(len(v["files"]) for v in index.values())
    total_tokens = sum(len(v.get("files", [])) * 1000 for v in index.values())
    import time
    uptime = int(time.time() - _SERVER_START_TIME) if '_SERVER_START_TIME' in globals() else 0  # noqa: F821 — voir ci-dessus

    # Memory
    vm = psutil.virtual_memory()
    mem_used_mb = round(vm.used / (1024 ** 2), 1)
    mem_total_mb = round(vm.total / (1024 ** 2), 1)
    mem_pct = round(vm.percent, 1)

    # CPU
    cpu_pct = psutil.cpu_percent(interval=None)

    # Disk
    disk_used_gb, disk_total_gb = _get_disk_stats()
    disk_free_gb = round(disk_total_gb - disk_used_gb, 2)
    disk_pct = round((disk_used_gb / disk_total_gb * 100) if disk_total_gb > 0 else 0, 1)

    # SSE connections (approximation)
    active_sessions = _count_active_sessions()

    # Backups
    from backend.admin import _scan_backups
    backup_rows = _scan_backups()
    total_backups = len(backup_rows)
    total_backup_size_mb = round(sum(r["size"] for r in backup_rows) / (1024 ** 2), 2)
    oldest_backup_age_days = 0.0
    if backup_rows:
        now_ts = int(time.time())
        oldest_ts = min(r["timestamp"] for r in backup_rows)
        oldest_backup_age_days = round((now_ts - oldest_ts) / 86400, 2)

    # Index details
    index_detail = {}
    for name, data in index.items():
        index_detail[name] = {
            "file_count": len(data["files"]),
            "tag_count": len(data.get("tags", [])),
            "token_count_approx": len(data.get("files", [])) * 1000,
        }

    return {
        "status": "ok",
        "version": get_version(),
        "vaults": len(index),
        "total_files": total_files,
        "total_tokens": total_tokens,
        "last_full_index_ts": _last_full_index_ts,
        "uptime_seconds": uptime,
        "git_describe": get_git_describe(),
        "git_commit": get_git_commit(),
        # Enriched fields
        "memory": {
            "used_mb": mem_used_mb,
            "total_mb": mem_total_mb,
            "percent": mem_pct,
        },
        "cpu": {
            "percent": cpu_pct,
        },
        "disk": {
            "used_gb": disk_used_gb,
            "total_gb": disk_total_gb,
            "free_gb": disk_free_gb,
            "percent": disk_pct,
        },
        "connections": {
            "active_sse": active_sessions,
        },
        "backups": {
            "total_count": total_backups,
            "total_size_mb": total_backup_size_mb,
            "oldest_age_days": oldest_backup_age_days,
        },
        "index": index_detail,
    }