package api_test

import (
	"bytes"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"

	"thuanle.me/claw-email-bridge/internal/api"
	"thuanle.me/claw-email-bridge/internal/database"
)

const testToken = "test-secret-token"

func setupTestRouter(t *testing.T) (*database.TestDB, *httptest.Server) {
	t.Helper()
	tdb := database.NewTestDB(t)
	router := api.NewRouter(tdb.DB, testToken, nil)
	srv := httptest.NewServer(router)
	t.Cleanup(func() { srv.Close() })
	return tdb, srv
}

// Test matrix #4: Callback sai token → 401, state không đổi.
func TestCallback_WrongToken_Returns401(t *testing.T) {
	tdb, srv := setupTestRouter(t)

	// Create a task in AI_PROCESSING state.
	task := &database.Task{
		TaskUUID:  "uuid-wrong-token",
		ThreadID:  "thread-1",
		MessageID: "msg-1",
		Sender:    "user@test.com",
		Subject:   "Test",
		Status:    database.StatusAIProcessing,
	}
	if err := database.CreateTask(tdb.DB, task); err != nil {
		t.Fatalf("create task: %v", err)
	}

	payload := map[string]any{
		"metadata": map[string]string{"task_uuid": "uuid-wrong-token"},
		"result":   "AI response",
		"status":   "ok",
	}
	body, _ := json.Marshal(payload)

	// No token.
	resp, err := http.Post(srv.URL+"/callback", "application/json", bytes.NewReader(body))
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusUnauthorized {
		t.Errorf("expected 401, got %d", resp.StatusCode)
	}

	// Wrong token.
	req, _ := http.NewRequest("POST", srv.URL+"/callback", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-Bridge-Token", "wrong-token")
	resp2, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer resp2.Body.Close()
	if resp2.StatusCode != http.StatusUnauthorized {
		t.Errorf("expected 401, got %d", resp2.StatusCode)
	}

	// Verify state unchanged.
	updated, err := database.FindByTaskUUID(tdb.DB, "uuid-wrong-token")
	if err != nil {
		t.Fatalf("find task: %v", err)
	}
	if updated.Status != database.StatusAIProcessing {
		t.Errorf("expected status AI_PROCESSING, got %s", updated.Status)
	}
	if updated.AIResponse != "" {
		t.Errorf("expected empty ai_response, got %q", updated.AIResponse)
	}
}

// Test matrix #1 (partial): callback hợp lệ → CALLBACK_DONE.
func TestCallback_ValidToken_UpdatesTask(t *testing.T) {
	tdb, srv := setupTestRouter(t)

	task := &database.Task{
		TaskUUID:  "uuid-valid",
		ThreadID:  "thread-1",
		MessageID: "msg-1",
		Sender:    "user@test.com",
		Subject:   "Test",
		Status:    database.StatusAIProcessing,
	}
	if err := database.CreateTask(tdb.DB, task); err != nil {
		t.Fatalf("create task: %v", err)
	}

	payload := map[string]any{
		"metadata": map[string]string{"task_uuid": "uuid-valid"},
		"result":   "Hello from AI",
		"status":   "ok",
	}
	body, _ := json.Marshal(payload)

	req, _ := http.NewRequest("POST", srv.URL+"/callback", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-Bridge-Token", testToken)
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("expected 200, got %d", resp.StatusCode)
	}

	updated, _ := database.FindByTaskUUID(tdb.DB, "uuid-valid")
	if updated.Status != database.StatusCallbackDone {
		t.Errorf("expected CALLBACK_DONE, got %s", updated.Status)
	}
	if updated.AIResponse != "Hello from AI" {
		t.Errorf("expected 'Hello from AI', got %q", updated.AIResponse)
	}
}

// Idempotent callback: task already COMPLETED → 200, no changes.
func TestCallback_AlreadyCompleted_Idempotent(t *testing.T) {
	tdb, srv := setupTestRouter(t)

	task := &database.Task{
		TaskUUID:   "uuid-completed",
		ThreadID:   "thread-1",
		MessageID:  "msg-1",
		Sender:     "user@test.com",
		Subject:    "Test",
		Status:     database.StatusCompleted,
		AIResponse: "Original response",
	}
	if err := database.CreateTask(tdb.DB, task); err != nil {
		t.Fatalf("create task: %v", err)
	}

	payload := map[string]any{
		"metadata": map[string]string{"task_uuid": "uuid-completed"},
		"result":   "New response that should be ignored",
		"status":   "ok",
	}
	body, _ := json.Marshal(payload)

	req, _ := http.NewRequest("POST", srv.URL+"/callback", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-Bridge-Token", testToken)
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("expected 200, got %d", resp.StatusCode)
	}

	updated, _ := database.FindByTaskUUID(tdb.DB, "uuid-completed")
	if updated.AIResponse != "Original response" {
		t.Errorf("expected original response preserved, got %q", updated.AIResponse)
	}
}

// Health endpoints.
func TestHealthz(t *testing.T) {
	_, srv := setupTestRouter(t)

	resp, err := http.Get(srv.URL + "/healthz")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Errorf("expected 200, got %d", resp.StatusCode)
	}
}

func TestReadyz(t *testing.T) {
	_, srv := setupTestRouter(t)

	resp, err := http.Get(srv.URL + "/readyz")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Errorf("expected 200, got %d", resp.StatusCode)
	}
}