package main

import (
	_ "apiserver/docs"
	"apiserver/backend"
	"apiserver/backend/auth"
	"apiserver/middleware"
	"apiserver/router"
	"apiserver/store"
	"apiserver/utils"
	logger "apiserver/utils"
	"context"
	"flag"
	"fmt"
	"io"
	"os"

	"apiserver/controllers"

	"github.com/gin-gonic/gin"
	"go.uber.org/zap"
)

// GitCommit and BuildTime are injected at link time via
// `-ldflags "-X main.GitCommit=... -X main.BuildTime=..."` (see
// src/tools/go_build and src/frontend/Makefile's build-server target). The
// "unknown" defaults matter: a bare `go build`/`go run` that bypasses that
// ldflags injection must still report "unknown" rather than an empty
// string, matching this feature's unknown-fallback requirement (see
// xce_version_field() in src/lib/utils.c for the equivalent C-side
// convention).
var (
	GitCommit = "unknown"
	BuildTime = "unknown"
)

func main() {
	gin.SetMode(gin.ReleaseMode)
	gin.DefaultWriter = io.Discard
	gin.DefaultErrorWriter = io.Discard

	topDir := flag.String("d", "", "Top directory (default: current directory)")
	versionFlag := flag.Bool("version", false, "Print version information and exit")
	flag.Usage = func() {
		fmt.Fprintln(os.Stderr, `
	Usage: apiserver -d <top_directory>
	       Top directory (default: current directory)
	`)
	}
	flag.Parse()

	// Checked before utils.InitLogger() runs so -version has no logging
	// side effects: it must only print and exit, matching controller's/
	// scheduler's/worker's own --version contract (Requirement 2.1).
	if *versionFlag {
		fmt.Printf("xce-apiserver %s built %s\n", GitCommit, BuildTime)
		return
	}

	utils.Global_TopDir = utils.PromptForTopDir(topDir)

	if err := utils.InitLogger(); err != nil {
		os.Exit(1)
	}
	logger.Info("********** Initialize Logger done!",
		zap.String("gitCommit", GitCommit),
		zap.String("buildTime", BuildTime))

	if err := utils.InitConf(); err != nil {
		logger.Error("Failed to initialize configuration files", zap.Error(err))
		os.Exit(1)
	}
	logger.Info("********** Initialize configuration files done!")

	// Initialize in-memory stores
	store.InitStores()
	logger.Info("********** Initialize in-memory stores done!")

	// Connect to the XCE controller backend for live data.
	// StartNotificationListener must be called before RegisterToBackend so the
	// handler is ready before any push events can arrive.
	if utils.BackendYamlConfig != nil && utils.BackendYamlConfig.Address != "" {
		handler := &backend.DefaultHandler{}
		if err := backend.StartNotificationListener(handler); err != nil {
			logger.Error("Failed to start notification listener", zap.Error(err))
			os.Exit(1)
		}
		bcfg := &backend.BackendConfig{
			Address: utils.BackendYamlConfig.Address,
			Port:    utils.BackendYamlConfig.Port,
			From:    utils.BackendYamlConfig.From,
			Key:     utils.BackendYamlConfig.Key,
			Peers:   utils.BackendYamlConfig.Peers,
		}
		if err := backend.RegisterToBackend(bcfg); err != nil {
			logger.Error("Failed to connect to backend", zap.Error(err))
			os.Exit(1)
		}
		logger.Info("********** Backend connection registered!")
		backend.StartHeartbeat(context.Background())
	} else {
		logger.Info("********** Backend not configured — running in stub mode")
	}

	// Load RBAC config
	rbacPath := utils.Global_TopDir + "/config/rbac.yaml"
	if err := controllers.LoadRBACConfig(rbacPath); err != nil {
		logger.Error("Failed to load RBAC config", zap.Error(err))
		os.Exit(1)
	}
	logger.Info("********** Load RBAC config done!")

	// Initialize auth provider
	authConfigPath := utils.Global_TopDir + "/config/auth.yaml"
	if err := auth.InitAuthProvider(authConfigPath); err != nil {
		logger.Error("Failed to initialize auth provider", zap.Error(err))
		os.Exit(1)
	}
	logger.Info("********** Initialize auth provider done! (" + auth.GlobalProvider.Name() + ")")

	// Pre-populate user-role store from auth provider so permissions work
	// immediately after restart without requiring users to re-login.
	if seeder, ok := auth.GlobalProvider.(auth.UserRoleSeeder); ok {
		for _, username := range seeder.AllUsers() {
			for _, role := range auth.GlobalProvider.GetUserRoles(username) {
				store.AddRoleForUser(username, role)
			}
		}
		logger.Info("********** Pre-populated user-role store from auth provider done!")
	}

	r := router.Router()
	if err := middleware.StartServer(r); err != nil {
		logger.Error("Server failed to start:", zap.Error(err))
		os.Exit(1)
	}
}