package main

import (
	"context"
	"errors"
	"net"
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"path/filepath"
	"testing"
	"time"

	"cmroubao/backend-api/internal/config"
	"cmroubao/backend-api/internal/platform/database"
	"cmroubao/backend-api/internal/platform/migration"
)

func TestLoadConfigUsesERPEnvironmentFile(t *testing.T) {
	environmentFile := filepath.Join(t.TempDir(), ".env")
	err := os.WriteFile(environmentFile, []byte(
		"CMROUBAO_SHUNYUNBAO_URL=https://erp.example.test\n"+
			"CMROUBAO_SHUNYUNBAO_USERNAME=dotenv-user\n"+
			"CMROUBAO_SHUNYUNBAO_PASSWORD=dotenv-password\n",
	), 0o600)
	if err != nil {
		t.Fatalf("os.WriteFile() error = %v", err)
	}

	cfg, err := loadConfig(func(name string) (string, bool) {
		if name == config.ShunyunbaoUsernameEnvironment {
			return "process-user", true
		}
		return "", false
	}, environmentFile)
	if err != nil {
		t.Fatalf("loadConfig() error = %v", err)
	}
	if cfg.ShunyunbaoURL != "https://erp.example.test" ||
		cfg.ShunyunbaoUsername != "process-user" ||
		cfg.ShunyunbaoPassword != "dotenv-password" {
		t.Fatalf(
			"ERP config = %#v",
			struct {
				URL      string
				Username string
				Password string
			}{cfg.ShunyunbaoURL, cfg.ShunyunbaoUsername, cfg.ShunyunbaoPassword},
		)
	}
}

func TestShutdownServerForceClosesAfterGracefulTimeout(t *testing.T) {
	handlerStarted := make(chan struct{})
	releaseHandler := make(chan struct{})
	server := &http.Server{
		Handler: http.HandlerFunc(func(http.ResponseWriter, *http.Request) {
			close(handlerStarted)
			<-releaseHandler
		}),
		ReadHeaderTimeout: time.Second,
	}
	listener, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("net.Listen() error = %v", err)
	}
	serverErrors := make(chan error, 1)
	go func() {
		serverErrors <- server.Serve(listener)
	}()

	requestFinished := make(chan struct{})
	go func() {
		defer close(requestFinished)
		client := http.Client{Timeout: time.Second}
		response, err := client.Get("http://" + listener.Addr().String())
		if err == nil {
			_ = response.Body.Close()
		}
	}()
	select {
	case <-handlerStarted:
	case <-time.After(time.Second):
		t.Fatal("handler did not start")
	}

	err = shutdownServer(server, serverErrors, 10*time.Millisecond)
	if err == nil {
		t.Fatal("shutdownServer() error = nil")
	}
	close(releaseHandler)
	select {
	case <-requestFinished:
	case <-time.After(time.Second):
		t.Fatal("request did not finish after force close")
	}
	connection, dialErr := net.DialTimeout(
		"tcp",
		listener.Addr().String(),
		100*time.Millisecond,
	)
	if dialErr == nil {
		_ = connection.Close()
		t.Fatal("listener still accepted connections after force close")
	}
}

func TestShutdownServerAcceptsNormalServerClose(t *testing.T) {
	serverErrors := make(chan error, 1)
	serverErrors <- http.ErrServerClosed
	server := &http.Server{}

	if err := shutdownServer(server, serverErrors, time.Second); err != nil &&
		!errors.Is(err, http.ErrServerClosed) {
		t.Fatalf("shutdownServer() error = %v", err)
	}
}

func TestRequireCurrentMigrationsAcceptsAppliedVersions(t *testing.T) {
	reader := stubMigrationStatusReader{
		statuses: []migration.Status{
			{Version: 1, Applied: true},
			{Version: 2, Applied: true},
		},
	}

	if err := requireCurrentMigrations(context.Background(), reader); err != nil {
		t.Fatalf("requireCurrentMigrations() error = %v", err)
	}
}

func TestRequireCurrentMigrationsRejectsPendingVersion(t *testing.T) {
	reader := stubMigrationStatusReader{
		statuses: []migration.Status{
			{Version: 1, Applied: true},
			{Version: 2, Applied: false},
		},
	}

	err := requireCurrentMigrations(context.Background(), reader)
	if err == nil || err.Error() !=
		"database migrations are pending; run migrate up" {
		t.Fatalf("requireCurrentMigrations() error = %v", err)
	}
}

func TestRequireCurrentMigrationsHidesStatusFailure(t *testing.T) {
	reader := stubMigrationStatusReader{err: errors.New("database details")}

	err := requireCurrentMigrations(context.Background(), reader)
	if err == nil || err.Error() != "database migration status failed" {
		t.Fatalf("requireCurrentMigrations() error = %v", err)
	}
}

func TestBuildRouterRegistersProtectedLogoutRoute(t *testing.T) {
	ctx := context.Background()
	db, err := database.Open(
		ctx,
		filepath.Join(t.TempDir(), "api.db"),
	)
	if err != nil {
		t.Fatalf("database.Open() error = %v", err)
	}
	defer db.Close()
	runner, err := migration.New(db)
	if err != nil {
		t.Fatalf("migration.New() error = %v", err)
	}
	if _, err := runner.Up(ctx); err != nil {
		t.Fatalf("migration.Up() error = %v", err)
	}
	router, err := buildRouter(ctx, config.Config{
		AssetDirectory:    filepath.Join(t.TempDir(), "assets"),
		ClaimLease:        10 * time.Minute,
		RunningLease:      30 * time.Minute,
		ReadinessTTL:      2 * time.Minute,
		ShunyunbaoURL:     "https://www.shunyunbaoerp.com",
		ShunyunbaoTimeout: 30 * time.Second,
	}, db)
	if err != nil {
		t.Fatalf("buildRouter() error = %v", err)
	}
	request := httptest.NewRequest(http.MethodPost, "/logout", nil)
	response := httptest.NewRecorder()

	router.ServeHTTP(response, request)

	if response.Code != http.StatusSeeOther ||
		response.Header().Get("Location") !=
			"/login?next=%2Ftasks" {
		t.Fatalf(
			"status/location = %d / %q",
			response.Code,
			response.Header().Get("Location"),
		)
	}
	for _, target := range []string{"/freight", "/freight/import", "/erp"} {
		request = httptest.NewRequest(http.MethodGet, target, nil)
		response = httptest.NewRecorder()
		router.ServeHTTP(response, request)
		if response.Code != http.StatusSeeOther ||
			response.Header().Get("Location") !=
				"/login?next="+url.QueryEscape(target) {
			t.Fatalf(
				"%s status/location = %d / %q",
				target,
				response.Code,
				response.Header().Get("Location"),
			)
		}
	}
	request = httptest.NewRequest(
		http.MethodGet,
		"/api/v1/freight-orders",
		nil,
	)
	response = httptest.NewRecorder()
	router.ServeHTTP(response, request)
	if response.Code != http.StatusUnauthorized ||
		response.Header().Get("Cache-Control") != "no-store" {
		t.Fatalf(
			"freight API status/cache = %d / %q",
			response.Code,
			response.Header().Get("Cache-Control"),
		)
	}
}

type stubMigrationStatusReader struct {
	statuses []migration.Status
	err      error
}

func (reader stubMigrationStatusReader) Status(
	context.Context,
) ([]migration.Status, error) {
	return reader.statuses, reader.err
}