package app

import (
	"context"
	"errors"
	"fmt"
	"net/http"
	"time"

	"git.apinb.com/ops/license/internal/config"
	"git.apinb.com/ops/license/internal/dashboard"
	"git.apinb.com/ops/license/internal/database"
	"git.apinb.com/ops/license/internal/httpapi"
	"git.apinb.com/ops/license/internal/issuance"
	"git.apinb.com/ops/license/internal/signing"
	"git.apinb.com/ops/license/internal/subject"
	"git.apinb.com/ops/license/internal/webui"
)

const shutdownTimeout = 10 * time.Second

// Run 装配并运行许可证管理服务，直到上下文被取消。
func Run(ctx context.Context, cfg config.Config) (resultErr error) {
	if ctx == nil {
		return errors.New("上下文不能为空")
	}

	db, err := database.Open(ctx, cfg.DatabaseDSN)
	if err != nil {
		return fmt.Errorf("打开数据库: %w", err)
	}
	sqlDB, err := db.DB()
	if err != nil {
		return fmt.Errorf("获取数据库连接池: %w", err)
	}
	defer func() {
		resultErr = errors.Join(resultErr, sqlDB.Close())
	}()

	if err := database.Migrate(ctx, db); err != nil {
		return fmt.Errorf("执行数据库迁移: %w", err)
	}
	activeSigner, err := signing.LoadActive(cfg.SigningPrivateKeyFile, cfg.SigningCertificateFile)
	if err != nil {
		return err
	}
	registry, err := signing.NewRegistry(db)
	if err != nil {
		return err
	}
	if err := registry.Activate(ctx, activeSigner); err != nil {
		return fmt.Errorf("激活当前签发密钥: %w", err)
	}

	subjectRepository, err := subject.NewRepository(db)
	if err != nil {
		return err
	}
	subjectService, err := subject.NewService(subjectRepository)
	if err != nil {
		return err
	}
	issuanceRepository, err := issuance.NewRepository(db)
	if err != nil {
		return err
	}
	fileSigner, err := issuance.NewFileSigner(activeSigner)
	if err != nil {
		return err
	}
	issuanceService, err := issuance.NewService(issuanceRepository, subjectRepository, fileSigner)
	if err != nil {
		return err
	}
	dashboardService, err := dashboard.NewService(db)
	if err != nil {
		return err
	}
	apiRouter, err := httpapi.NewRouter(subjectService, issuanceService, dashboardService)
	if err != nil {
		return err
	}

	handler := http.NewServeMux()
	handler.Handle("/api/", apiRouter)
	handler.Handle("/", webui.Handler())
	server := &http.Server{
		Addr:              cfg.ListenAddr,
		Handler:           handler,
		ReadHeaderTimeout: 10 * time.Second,
	}

	serveResult := make(chan error, 1)
	go func() {
		serveResult <- server.ListenAndServe()
	}()

	select {
	case err := <-serveResult:
		if errors.Is(err, http.ErrServerClosed) {
			return nil
		}
		return fmt.Errorf("运行 HTTP 服务: %w", err)
	case <-ctx.Done():
		shutdownContext, cancel := context.WithTimeout(context.Background(), shutdownTimeout)
		defer cancel()
		if err := server.Shutdown(shutdownContext); err != nil {
			return fmt.Errorf("关闭 HTTP 服务: %w", err)
		}
		serveErr := <-serveResult
		if serveErr != nil && !errors.Is(serveErr, http.ErrServerClosed) {
			return fmt.Errorf("关闭 HTTP 服务: %w", serveErr)
		}
		return nil
	}
}