import asyncio
from typing import Annotated

from core_domain import ServiceDescriptor, ServiceHealth
from fastapi import APIRouter, Depends, HTTPException, Query, Request, Response
from sqlalchemy import text
from sqlalchemy.orm import Session

from app.bootstrap.settings import ApiGatewaySettings
from app.db.session import get_db
from app.domain.repositories import ApiKeyRepository, GatewayRequestAuditRepository
from app.infrastructure.api_keys import generate_api_key, get_api_key_prefix, hash_api_key
from app.infrastructure.proxy import ProxyServiceName, ProxyTarget, ServiceProxy
from app.schemas.gateway import (
    ApiKeyCreateRequest,
    ApiKeyCreateResponse,
    ApiKeyListRequest,
    ApiKeyResponse,
    ApiKeyStatusPostRequest,
    ApiKeyStatusUpdateRequest,
    GatewayAuditServiceStats,
    GatewayAuditStatsResponse,
    GatewayRequestAuditResponse,
    GatewayServicesHealthResponse,
)

router = APIRouter()
DbSession = Annotated[Session, Depends(get_db)]


@router.get("/health", response_model=ServiceDescriptor)
def health_check(db: DbSession) -> ServiceDescriptor:
    db.execute(text("SELECT 1"))
    return ServiceDescriptor(name="api-gateway")


@router.get("/ready", response_model=ServiceHealth)
def readiness_check(db: DbSession) -> ServiceHealth:
    db.execute(text("SELECT 1"))
    return ServiceHealth(service="api-gateway", status="ok", database="ok")


@router.post("/gateway/api-keys", response_model=ApiKeyCreateResponse)
def create_api_key(
    payload: ApiKeyCreateRequest,
    db: DbSession) -> ApiKeyCreateResponse:
    api_key = generate_api_key()
    entity = ApiKeyRepository(db).create(
        name=payload.name,
        key_prefix=get_api_key_prefix(api_key),
        key_hash=hash_api_key(api_key),
        scopes=payload.scopes,
        expires_time=payload.expires_time)
    return ApiKeyCreateResponse(
        id=entity.id,
        name=entity.name,
        key_prefix=entity.key_prefix,
        api_key=api_key,
        status=entity.status,
        scopes=entity.scopes,
        expires_time=entity.expires_time,
        created_time=entity.created_time)


@router.get("/gateway/api-keys", response_model=list[ApiKeyResponse])
def list_api_keys(
    db: DbSession) -> list[ApiKeyResponse]:
    return [
        ApiKeyResponse.from_entity(item)
        for item in ApiKeyRepository(db).list_all()
    ]


@router.post("/gateway/api-keys/list", response_model=list[ApiKeyResponse])
def list_api_keys_post(
    payload: ApiKeyListRequest,
    db: DbSession) -> list[ApiKeyResponse]:
    return [
        ApiKeyResponse.from_entity(item)
        for item in ApiKeyRepository(db).list_all()
    ]


@router.patch("/gateway/api-keys/{api_key_id}/status", response_model=ApiKeyResponse)
def update_api_key_status(
    api_key_id: str,
    payload: ApiKeyStatusUpdateRequest,
    db: DbSession) -> ApiKeyResponse:
    entity = ApiKeyRepository(db).update_status(
        api_key_id=api_key_id,
        status=payload.status)
    if entity is None:
        raise HTTPException(status_code=404, detail=f"api key not found: {api_key_id}")
    return ApiKeyResponse.from_entity(entity)


@router.post("/gateway/api-keys/status", response_model=ApiKeyResponse)
def update_api_key_status_post(
    payload: ApiKeyStatusPostRequest,
    db: DbSession) -> ApiKeyResponse:
    entity = ApiKeyRepository(db).update_status(
        api_key_id=payload.api_key_id,
        status=payload.status)
    if entity is None:
        raise HTTPException(status_code=404, detail=f"api key not found: {payload.api_key_id}")
    return ApiKeyResponse.from_entity(entity)


@router.get("/gateway/audits", response_model=list[GatewayRequestAuditResponse])
def list_gateway_audits(
    db: DbSession,
    request_id: Annotated[str | None, Query()] = None,
    target_service: Annotated[str | None, Query()] = None,
    limit: Annotated[int, Query(ge=1, le=500)] = 100) -> list[GatewayRequestAuditResponse]:
    items = GatewayRequestAuditRepository(db).list_by_scope(
        request_id=request_id,
        target_service=target_service,
        limit=limit)
    return [GatewayRequestAuditResponse.from_entity(item) for item in items]


@router.get("/gateway/audits/stats", response_model=GatewayAuditStatsResponse)
def gateway_audit_stats(
    db: DbSession) -> GatewayAuditStatsResponse:
    rows = GatewayRequestAuditRepository(db).stats_by_service()
    services = [
        GatewayAuditServiceStats(
            target_service=target_service,
            request_count=request_count,
            error_count=error_count,
            average_duration_ms=round(average_duration_ms, 2))
        for target_service, request_count, error_count, average_duration_ms in rows
    ]
    return GatewayAuditStatsResponse(
        total_request_count=sum(item.request_count for item in services),
        total_error_count=sum(item.error_count for item in services),
        services=services)


def get_gateway_settings() -> ApiGatewaySettings:
    return ApiGatewaySettings()


def get_service_proxy(
    settings: Annotated[ApiGatewaySettings, Depends(get_gateway_settings)]) -> ServiceProxy:
    return ServiceProxy(settings=settings, timeout_seconds=settings.proxy_timeout_seconds)


GatewaySettingsDep = Annotated[ApiGatewaySettings, Depends(get_gateway_settings)]
ServiceProxyDep = Annotated[ServiceProxy, Depends(get_service_proxy)]


def build_proxy_targets(settings: ApiGatewaySettings) -> dict[ProxyServiceName, ProxyTarget]:
    return {
        "session-service": ProxyTarget(
            service_name="session-service",
            base_url=settings.session_service_url,
            path_prefix="/sessions",
            health_path="/sessions/health"),
        "tool-service": ProxyTarget(
            service_name="tool-service",
            base_url=settings.tool_service_url,
            path_prefix="/tools",
            health_path="/tools/health"),
        "model-gateway-service": ProxyTarget(
            service_name="model-gateway-service",
            base_url=settings.model_gateway_service_url,
            path_prefix="/models",
            health_path="/models/health"),
        "model-provider-service": ProxyTarget(
            service_name="model-provider-service",
            base_url=settings.model_gateway_service_url,
            path_prefix="/models/providers",
            health_path="/models/health"),
        "code-runner-service": ProxyTarget(
            service_name="code-runner-service",
            base_url=settings.code_runner_service_url,
            path_prefix="/code",
            health_path="/code/health"),
        "agent-service": ProxyTarget(
            service_name="agent-service",
            base_url=settings.agent_service_url,
            path_prefix="/agents",
            health_path="/agents/health"),
        "memory-service": ProxyTarget(
            service_name="memory-service",
            base_url=settings.memory_service_url,
            path_prefix="/memories",
            health_path="/memories/health"),
        "team-service": ProxyTarget(
            service_name="team-service",
            base_url=settings.team_service_url,
            path_prefix="/teams",
            health_path="/teams/health"),
        "skill-service": ProxyTarget(
            service_name="skill-service",
            base_url=settings.skill_service_url,
            path_prefix="/skills",
            health_path="/skills/health"),
        "human-service": ProxyTarget(
            service_name="human-service",
            base_url=settings.human_service_url,
            path_prefix="/human",
            health_path="/human/health"),
        "knowledge-service": ProxyTarget(
            service_name="knowledge-service",
            base_url=settings.knowledge_service_url,
            path_prefix="/knowledge",
            health_path="/knowledge/health"),
        "event-service": ProxyTarget(
            service_name="event-service",
            base_url=settings.event_service_url,
            path_prefix="/events",
            health_path="/events/health"),
        "identity-service": ProxyTarget(
            service_name="identity-service",
            base_url=settings.auth_service_url,
            path_prefix="/identity",
            health_path="/identity/health"),
        "scheduler-service": ProxyTarget(
            service_name="scheduler-service",
            base_url=settings.scheduler_service_url,
            path_prefix="/scheduler",
            health_path="/scheduler/health"),
    }


@router.get("/gateway/services/health", response_model=GatewayServicesHealthResponse)
async def downstream_health_check(
    settings: GatewaySettingsDep) -> GatewayServicesHealthResponse:
    targets = build_proxy_targets(settings)
    health_proxy = ServiceProxy(
        settings=settings,
        timeout_seconds=settings.downstream_health_timeout_seconds)
    downstream_services = await asyncio.gather(
        *[health_proxy.check_health(target) for target in targets.values()]
    )
    status = "ok" if all(item.status == "ok" for item in downstream_services) else "degraded"
    return GatewayServicesHealthResponse(
        status=status,
        downstream_services=downstream_services)


@router.api_route(
    "/gateway/sessions",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
@router.api_route(
    "/gateway/sessions/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
async def proxy_session_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["session-service"],
        path=path)


@router.api_route(
    "/gateway/agents",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
@router.api_route(
    "/gateway/agents/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
async def proxy_agent_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["agent-service"],
        path=path)


@router.api_route(
    "/gateway/memories",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
@router.api_route(
    "/gateway/memories/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
async def proxy_memory_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["memory-service"],
        path=path)


@router.api_route(
    "/gateway/teams",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
@router.api_route(
    "/gateway/teams/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
async def proxy_team_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["team-service"],
        path=path)


@router.api_route(
    "/gateway/skills",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
@router.api_route(
    "/gateway/skills/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
async def proxy_skill_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["skill-service"],
        path=path)


@router.api_route(
    "/gateway/human",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
@router.api_route(
    "/gateway/human/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
async def proxy_human_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["human-service"],
        path=path)


@router.api_route(
    "/gateway/knowledge",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
@router.api_route(
    "/gateway/knowledge/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
async def proxy_knowledge_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["knowledge-service"],
        path=path)


@router.api_route(
    "/gateway/events",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
@router.api_route(
    "/gateway/events/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
async def proxy_event_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["event-service"],
        path=path)


@router.api_route(
    "/gateway/identity",
    methods=["POST"])
@router.api_route(
    "/gateway/identity/{path:path}",
    methods=["POST"])
async def proxy_identity_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["identity-service"],
        path=path)


@router.api_route(
    "/gateway/scheduler",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
@router.api_route(
    "/gateway/scheduler/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
async def proxy_scheduler_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["scheduler-service"],
        path=path)


@router.api_route(
    "/gateway/tools",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
@router.api_route(
    "/gateway/tools/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
async def proxy_tool_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["tool-service"],
        path=path)


@router.api_route(
    "/gateway/models",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
@router.api_route(
    "/gateway/models/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
async def proxy_model_gateway_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["model-gateway-service"],
        path=path)


@router.api_route(
    "/gateway/model-providers",
    methods=["POST"])
@router.api_route(
    "/gateway/model-providers/{path:path}",
    methods=["POST"])
async def proxy_model_provider_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["model-provider-service"],
        path=path)


@router.api_route(
    "/gateway/code",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
@router.api_route(
    "/gateway/code/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"])
async def proxy_code_runner_service(
    request: Request,
    settings: GatewaySettingsDep,
    proxy: ServiceProxyDep,
    path: str = "") -> Response:
    return await proxy.forward(
        request=request,
        target=build_proxy_targets(settings)["code-runner-service"],
        path=path)