package operations

import (
	"context"
	"net/http"
	"runtime"
	"time"

	"aigateway.local/core/internal/identity"
	"aigateway.local/core/internal/platform/apiresponse"
	"github.com/jackc/pgx/v5/pgxpool"
)

type AdminHTTPHandler struct {
	pool      *pgxpool.Pool
	identity  *identity.Service
	version   string
	startedAt time.Time
	reload    func(context.Context) error
	mux       *http.ServeMux
}

func NewAdminHTTPHandler(pool *pgxpool.Pool, identityService *identity.Service, version string, startedAt time.Time, reload func(context.Context) error) *AdminHTTPHandler {
	h := &AdminHTTPHandler{pool: pool, identity: identityService, version: version, startedAt: startedAt, reload: reload, mux: http.NewServeMux()}
	h.mux.HandleFunc("GET /api/v1/admin/system-info", h.systemInfo)
	h.mux.HandleFunc("GET /api/v1/admin/monitoring/overview", h.overview)
	h.mux.HandleFunc("POST /api/v1/admin/reload", h.reloadSnapshots)
	return h
}

func (h *AdminHTTPHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { h.mux.ServeHTTP(w, r) }

func (h *AdminHTTPHandler) account(w http.ResponseWriter, r *http.Request) (identity.Account, bool) {
	account, err := h.identity.Authenticate(r.Context(), identity.KindAdmin, r.Header.Get("Authorization"))
	if err != nil {
		apiresponse.Error(w, http.StatusUnauthorized, "登录状态无效")
		return identity.Account{}, false
	}
	return account, true
}

func (h *AdminHTTPHandler) systemInfo(w http.ResponseWriter, r *http.Request) {
	if _, ok := h.account(w, r); !ok {
		return
	}
	var providers, models, keys int64
	if err := h.pool.QueryRow(r.Context(), `SELECT (SELECT count(*) FROM gateway.providers WHERE enabled),(SELECT count(*) FROM gateway.provider_models WHERE enabled),(SELECT count(*) FROM gateway.api_keys WHERE enabled)`).Scan(&providers, &models, &keys); err != nil {
		apiresponse.Error(w, http.StatusServiceUnavailable, "系统信息查询失败")
		return
	}
	apiresponse.OK(w, map[string]any{"version": h.version, "go_version": runtime.Version(), "uptime_seconds": int64(time.Since(h.startedAt).Seconds()), "database": "postgresql", "object_storage": true, "clickhouse": false, "enabled_providers": providers, "enabled_models": models, "enabled_api_keys": keys})
}

func (h *AdminHTTPHandler) overview(w http.ResponseWriter, r *http.Request) {
	if _, ok := h.account(w, r); !ok {
		return
	}
	var requests, failures, promptTokens, completionTokens, cost int64
	var latency *float64
	err := h.pool.QueryRow(r.Context(), `SELECT count(*),count(*) FILTER(WHERE coalesce(status_code,500)>=400),coalesce(sum(prompt_tokens),0),coalesce(sum(completion_tokens),0),coalesce(sum(cost_microunits),0),avg(latency_ms) FROM gateway.audit_events WHERE recorded_at>=clock_timestamp()-interval '24 hours'`).Scan(&requests, &failures, &promptTokens, &completionTokens, &cost, &latency)
	if err != nil {
		apiresponse.Error(w, http.StatusServiceUnavailable, "监控汇总查询失败")
		return
	}
	apiresponse.OK(w, map[string]any{"window": "24h", "requests": requests, "failed_requests": failures, "prompt_tokens": promptTokens, "completion_tokens": completionTokens, "cost_microunits": cost, "avg_latency_ms": latency})
}

func (h *AdminHTTPHandler) reloadSnapshots(w http.ResponseWriter, r *http.Request) {
	account, ok := h.account(w, r)
	if !ok {
		return
	}
	if !identity.HasPermission(account, identity.PermissionProviderManage) {
		apiresponse.Error(w, http.StatusForbidden, "缺少运行时配置管理权限")
		return
	}
	if h.reload != nil {
		if err := h.reload(r.Context()); err != nil {
			apiresponse.Error(w, http.StatusServiceUnavailable, "运行时快照刷新不完整: "+err.Error())
			return
		}
	}
	apiresponse.OK(w, map[string]bool{"reloaded": true})
}
