package imap_server

import (
	"path/filepath"
	"testing"
	"time"

	"mail_go/config"
	"mail_go/internal/connhub"
	"mail_go/internal/db"
	"mail_go/internal/store"

	"github.com/emersion/go-imap/backend"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
)

// TestNotifyNewMessage 验证本地投递成功后推送的 MessageUpdate 内容正确。
func TestNotifyNewMessage(t *testing.T) {
	gdb, err := gorm.Open(sqlite.Open(filepath.Join(t.TempDir(), "test.db")), &gorm.Config{})
	if err != nil {
		t.Fatalf("open sqlite: %v", err)
	}
	if err := gdb.AutoMigrate(&db.User{}, &db.Domain{}, &db.Message{}); err != nil {
		t.Fatalf("migrate: %v", err)
	}
	stores := store.NewStores(gdb)

	domain := &db.Domain{Name: "example.com"}
	if err := stores.Domains.Create(domain); err != nil {
		t.Fatalf("create domain: %v", err)
	}
	user := &db.User{Username: "alice", DomainID: domain.ID, IsActive: true}
	if err := stores.Users.Create(user); err != nil {
		t.Fatalf("create user: %v", err)
	}
	email := "alice@example.com"

	// 已有一封旧邮件，新邮件应为 INBOX 第 2 封
	old := &db.Message{UserID: user.ID, Folder: "INBOX", FromAddr: "x@y", Subject: "old", Date: time.Now()}
	if err := stores.Mails.Create(old); err != nil {
		t.Fatalf("create old message: %v", err)
	}
	inboxMsg := &db.Message{
		UserID:    user.ID,
		Folder:    "INBOX",
		FromAddr:  "sender@other.com",
		ToAddr:    email,
		Subject:   "新邮件",
		RawData:   "From: sender@other.com\r\nSubject: 新邮件\r\n\r\nhello",
		MessageID: "<new-1@other.com>",
		Date:      time.Now(),
		IsRead:    false,
	}
	if err := stores.Mails.Create(inboxMsg); err != nil {
		t.Fatalf("create message: %v", err)
	}

	hub := connhub.New()
	srv := NewIMAPServer(config.IMAPConfig{}, stores, nil, config.BanConfig{}, hub)
	// 模拟明文 + TLS 两个监听器（生产环境由 Start/StartTLS 注册）
	srv.newServer("127.0.0.1:143", nil)
	srv.newServer("127.0.0.1:993", nil)
	srv.NotifyNewMessage(email, inboxMsg)

	// 两个监听器（明文/TLS）各有一个 backend 通道，都应收到同一更新
	srv.beMu.Lock()
	bes := append([]*imapBackend(nil), srv.bes...)
	srv.beMu.Unlock()
	if len(bes) == 0 {
		t.Fatal("no backends registered")
	}

	for i, b := range bes {
		select {
		case upd := <-b.updates:
			mu, ok := upd.(*backend.MessageUpdate)
			if !ok {
				t.Fatalf("backend %d: update type = %T, want *MessageUpdate", i, upd)
			}
			if mu.Username() != email {
				t.Fatalf("backend %d: username = %q, want %q", i, mu.Username(), email)
			}
			if mu.Mailbox() != "INBOX" {
				t.Fatalf("backend %d: mailbox = %q, want INBOX", i, mu.Mailbox())
			}
			if mu.Message.Uid != uint32(inboxMsg.ID) {
				t.Fatalf("backend %d: uid = %d, want %d", i, mu.Message.Uid, inboxMsg.ID)
			}
			if mu.Message.SeqNum != 2 {
				t.Fatalf("backend %d: seq = %d, want 2", i, mu.Message.SeqNum)
			}
			if mu.Message.Envelope == nil || mu.Message.Envelope.Subject != "新邮件" {
				t.Fatalf("backend %d: envelope missing subject", i)
			}
		case <-time.After(time.Second):
			t.Fatalf("backend %d: no update received", i)
		}
	}
}

// TestNotifyNewMessageChannelFull 验证通道满时推送不阻塞（非阻塞丢弃）。
func TestNotifyNewMessageChannelFull(t *testing.T) {
	gdb, err := gorm.Open(sqlite.Open(filepath.Join(t.TempDir(), "test.db")), &gorm.Config{})
	if err != nil {
		t.Fatalf("open sqlite: %v", err)
	}
	if err := gdb.AutoMigrate(&db.User{}, &db.Domain{}, &db.Message{}); err != nil {
		t.Fatalf("migrate: %v", err)
	}
	stores := store.NewStores(gdb)

	hub := connhub.New()
	srv := NewIMAPServer(config.IMAPConfig{}, stores, nil, config.BanConfig{}, hub)
	srv.newServer("127.0.0.1:143", nil)
	srv.newServer("127.0.0.1:993", nil)

	msg := &db.Message{ID: 1, Folder: "INBOX", Date: time.Now()}
	done := make(chan struct{})
	go func() {
		// 灌满所有 backend 通道（容量 256），再调用必须立即返回
		srv.beMu.Lock()
		bes := append([]*imapBackend(nil), srv.bes...)
		srv.beMu.Unlock()
		for _, b := range bes {
			for i := 0; i < cap(b.updates); i++ {
				b.updates <- backend.NewUpdate("a@b", "INBOX")
			}
		}
		srv.NotifyNewMessage("a@b", msg)
		close(done)
	}()

	select {
	case <-done:
	case <-time.After(time.Second):
		t.Fatal("NotifyNewMessage blocked on full channel")
	}
}

// TestNotifyNewMessageNilSafe 验证空参数/空指针安全。
func TestNotifyNewMessageNilSafe(t *testing.T) {
	var srv *IMAPServer
	srv.NotifyNewMessage("a@b", &db.Message{ID: 1}) // 不应 panic
	srv = NewIMAPServer(config.IMAPConfig{}, nil, nil, config.BanConfig{}, nil)
	srv.NotifyNewMessage("", &db.Message{ID: 1}) // 空邮箱
	srv.NotifyNewMessage("a@b", nil)             // 空消息
}