package notify

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"path/filepath"
	"strings"
	"testing"

	"github.com/agentmail/gateway/internal/db"
	"github.com/agentmail/gateway/internal/models"
	"github.com/agentmail/gateway/internal/repo"
	"github.com/agentmail/gateway/internal/sse"
	"github.com/google/uuid"
)

func setupTestDB(t *testing.T) {
	t.Helper()
	dir := t.TempDir()
	if err := db.Connect(context.Background(), filepath.Join(dir, "test.db")); err != nil {
		t.Fatalf("connect: %v", err)
	}
	if err := db.Migrate(context.Background()); err != nil {
		t.Fatalf("migrate: %v", err)
	}
	t.Cleanup(db.Close)
}

func seedAgent(t *testing.T, name string) {
	t.Helper()
	if _, err := db.DB.ExecContext(context.Background(),
		`INSERT INTO agents (agent_name, secret, platform, status) VALUES ($1, 'x', $1, 'online')`,
		name); err != nil {
		t.Fatalf("seed agent %s: %v", name, err)
	}
}

// attach 挂一个真实的 SSE 客户端并返回「读出这个 Agent 收到的 new_mail payload」的闭包。
//
// 走真实的 sse.Default 而不是替换发送函数：要验的正是「谁收到什么」，
// 而分发逻辑就在 Manager 里 —— 把它换掉等于不验。
func attach(t *testing.T, agentName string) func() map[string]any {
	t.Helper()
	rec := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/api/v1/events/stream", nil)
	c := sse.Default.AddClient(rec, req, agentName, "")
	if c == nil {
		t.Fatalf("AddClient(%s) 返回 nil", agentName)
	}
	t.Cleanup(func() { sse.Default.RemoveClient(c.ID) })

	return func() map[string]any {
		// SSE 帧形如 `id: N\nevent: new_mail\ndata: {…}\n\n`
		for _, frame := range strings.Split(rec.Body.String(), "\n\n") {
			if !strings.Contains(frame, "event: new_mail") {
				continue
			}
			for _, line := range strings.Split(frame, "\n") {
				if !strings.HasPrefix(line, "data: ") {
					continue
				}
				var m map[string]any
				if err := json.Unmarshal([]byte(strings.TrimPrefix(line, "data: ")), &m); err == nil {
					return m
				}
			}
		}
		return nil
	}
}

// seedAdopted 建一条接管了 owner 的平台会话的本侧会话。
func seedAdopted(t *testing.T, owner, platformID, workspace string) uuid.UUID {
	t.Helper()
	ctx := context.Background()
	if err := repo.ReplacePlatformSessions(ctx, owner, []repo.PlatformSession{
		{PlatformID: platformID, Workspace: workspace, Slug: "项目定位", Title: "项目定位"},
	}); err != nil {
		t.Fatalf("ReplacePlatformSessions: %v", err)
	}
	id, err := repo.AdoptPlatformSession(ctx, owner, platformID, "项目定位", workspace, "项目定位")
	if err != nil {
		t.Fatalf("AdoptPlatformSession: %v", err)
	}
	return id
}

// platform_session_id 只该发给归属方。
//
// 生产事故：会话接管了 pi 的 `01a05a5e-…`，而那封邮件抄送了 dsh。DSH 收到同一个
// id，在 `~/.dsh/sessions/` 里查不到（那是 `/root/.pi/agent/sessions/` 下的文件），
// 于是按 N-8 抛「平台侧会话已删」——邮件静默消失，日志里一个字都没有。
func TestRecipients_PlatformIDOnlyToOwner(t *testing.T) {
	setupTestDB(t)
	seedAgent(t, "pi")
	seedAgent(t, "dsh")
	readPi, readDsh := attach(t, "pi"), attach(t, "dsh")

	sessionID := seedAdopted(t, "pi", "pid-pi-1", "/w")

	Recipients(context.Background(), Mail{
		SessionID: sessionID,
		MailID:    uuid.New(),
		From:      "jianf",
		To:        models.Address{Name: "pi", Path: "/w"},
		CC:        []models.Address{{Name: "dsh", Path: "/w"}},
		Subject:   "任务",
	})

	pi, dsh := readPi(), readDsh()
	if pi == nil {
		t.Fatal("归属方 pi 没收到 new_mail")
	}
	if dsh == nil {
		t.Fatal("抄送方 dsh 没收到 new_mail（抄送方必须单独推）")
	}
	if v := pi["platform_session_id"]; v != "pid-pi-1" {
		t.Errorf("归属方 pi 的 platform_session_id = %v, want pid-pi-1", v)
	}
	if v := dsh["platform_session_id"]; v != "" {
		t.Errorf("抄送方 dsh 的 platform_session_id = %v, want 空串（那是 pi 的会话文件）", v)
	}
}

// 归属方在抄送位上也要拿到：归属与收件角色无关。
func TestRecipients_PlatformIDToOwnerEvenAsCC(t *testing.T) {
	setupTestDB(t)
	seedAgent(t, "pi")
	seedAgent(t, "dsh")
	readPi, readDsh := attach(t, "pi"), attach(t, "dsh")

	sessionID := seedAdopted(t, "pi", "pid-pi-2", "/w")

	Recipients(context.Background(), Mail{
		SessionID: sessionID,
		MailID:    uuid.New(),
		From:      "jianf",
		To:        models.Address{Name: "dsh", Path: "/w"},
		CC:        []models.Address{{Name: "pi", Path: "/w"}},
		Subject:   "任务",
	})

	if v := readPi()["platform_session_id"]; v != "pid-pi-2" {
		t.Errorf("抄送位上的归属方 pi = %v, want pid-pi-2", v)
	}
	if v := readDsh()["platform_session_id"]; v != "" {
		t.Errorf("主收件人 dsh = %v, want 空串", v)
	}
}

// 普通（非接管）会话：谁都不该拿到 platform id。
func TestRecipients_PlainSessionNoPlatformID(t *testing.T) {
	setupTestDB(t)
	seedAgent(t, "pi")
	readPi := attach(t, "pi")

	id, err := repo.CreateSession(context.Background(), nil, "pi", "普通", "/w")
	if err != nil {
		t.Fatalf("CreateSession: %v", err)
	}
	Recipients(context.Background(), Mail{
		SessionID: id, MailID: uuid.New(), From: "jianf",
		To: models.Address{Name: "pi", Path: "/w"}, Subject: "任务",
	})

	if v := readPi()["platform_session_id"]; v != "" {
		t.Errorf("普通会话 = %v, want 空串", v)
	}
}