"""
matrix-bridge-dagi — Phase M1 scaffold
Bridges Matrix/Element rooms to DAGI agents via Gateway.

M1 scope: 1 room ↔ 1 agent (Sofiia), audit via sofiia-console internal endpoint.
"""
import logging
import os
import time
from contextlib import asynccontextmanager
from typing import Any, Dict

from fastapi import FastAPI, Response
from fastapi.middleware.cors import CORSMiddleware

try:
    from prometheus_client import (
        Counter, Histogram, Gauge,
        generate_latest, CONTENT_TYPE_LATEST,
        CollectorRegistry, REGISTRY,
    )
    _PROM_OK = True
except ImportError:  # pragma: no cover
    _PROM_OK = False

from .config import BridgeConfig, load_config

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s %(levelname)s %(name)s %(message)s",
)
logger = logging.getLogger("matrix-bridge-dagi")

# ── Prometheus metrics ────────────────────────────────────────────────────────
if _PROM_OK:
    _messages_received = Counter(
        "matrix_bridge_messages_received_total",
        "Total Matrix messages received",
        ["room_id", "agent_id"],
    )
    _messages_replied = Counter(
        "matrix_bridge_messages_replied_total",
        "Total agent replies sent to Matrix",
        ["room_id", "agent_id", "status"],
    )
    _gateway_errors = Counter(
        "matrix_bridge_gateway_errors_total",
        "Errors calling DAGI gateway",
        ["error_type"],
    )
    _invoke_latency = Histogram(
        "matrix_bridge_invoke_duration_seconds",
        "Duration of DAGI invoke call",
        ["agent_id"],
    )
    _bridge_up = Gauge(
        "matrix_bridge_up",
        "1 if bridge started successfully",
    )

# ── Startup state ─────────────────────────────────────────────────────────────
_START_TIME = time.monotonic()
_cfg: BridgeConfig | None = None
_config_error: str | None = None

# ── Lifespan ──────────────────────────────────────────────────────────────────
@asynccontextmanager
async def lifespan(app_: Any):
    global _cfg, _config_error
    try:
        _cfg = load_config()
        logger.info(
            "✅ matrix-bridge-dagi started | node=%s build=%s homeserver=%s room=%s agents=%s",
            _cfg.node_id, _cfg.build_sha, _cfg.matrix_homeserver_url,
            _cfg.sofiia_room_id, list(_cfg.bridge_allowed_agents),
        )
        if _PROM_OK:
            _bridge_up.set(1)
    except RuntimeError as exc:
        _config_error = str(exc)
        logger.error("❌ Config error: %s", _config_error)
        if _PROM_OK:
            _bridge_up.set(0)
    yield
    logger.info("matrix-bridge-dagi shutting down")

# ── App ───────────────────────────────────────────────────────────────────────
app = FastAPI(
    title="matrix-bridge-dagi",
    version="0.1.0",
    lifespan=lifespan,
)

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["GET", "POST"],
    allow_headers=["*"],
)

# ── Health ────────────────────────────────────────────────────────────────────
@app.get("/health")
async def health() -> Dict[str, Any]:
    uptime = int(time.monotonic() - _START_TIME)
    if _config_error or _cfg is None:
        return {
            "ok": False,
            "service": "matrix-bridge-dagi",
            "version": "0.1.0",
            "build": os.getenv("BUILD_SHA", "dev"),
            "uptime_s": uptime,
            "error": _config_error or "service not initialised",
        }
    return {
        "ok": True,
        "service": "matrix-bridge-dagi",
        "version": "0.1.0",
        "build": _cfg.build_sha,
        "build_time": _cfg.build_time,
        "env": os.getenv("ENV", "dev"),
        "uptime_s": uptime,
        "node_id": _cfg.node_id,
        "homeserver": _cfg.matrix_homeserver_url,
        "bridge_user": _cfg.matrix_user_id,
        "sofiia_room_id": _cfg.sofiia_room_id,
        "allowed_agents": list(_cfg.bridge_allowed_agents),
        "gateway": _cfg.dagi_gateway_url,
        "config_ok": True,
    }

# ── Metrics ───────────────────────────────────────────────────────────────────
@app.get("/metrics")
async def metrics():
    if not _PROM_OK:
        return Response("# prometheus_client not available\n", media_type="text/plain")
    return Response(generate_latest(REGISTRY), media_type=CONTENT_TYPE_LATEST)