package stats

import (
	"context"
	"database/sql"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"github.com/DATA-DOG/go-sqlmock"
)

func TestMetricRepositoryQueriesDailyMetricsWithFilters(t *testing.T) {
	db, mock, err := sqlmock.New()
	if err != nil {
		t.Fatalf("sqlmock.New() error = %v", err)
	}
	defer db.Close()
	mock.ExpectQuery("SELECT vehicle_key, vin, stat_date, protocol, metric_key, metric_value, metric_unit, first_total_mileage_km, latest_total_mileage_km, sample_count, calculation_method, created_at, updated_at FROM vehicle_daily_metric").
		WithArgs("LKLG7C4E3NA774736", "JT808", "2026-07-01", "2026-07-01", 20, 0).
		WillReturnRows(sqlmock.NewRows([]string{
			"vehicle_key", "vin", "stat_date", "protocol", "metric_key", "metric_value", "metric_unit",
			"first_total_mileage_km", "latest_total_mileage_km", "sample_count", "calculation_method",
			"created_at", "updated_at",
		}).AddRow(
			"LKLG7C4E3NA774736", "LKLG7C4E3NA774736", time.Date(2026, 7, 1, 0, 0, 0, 0, time.FixedZone("Asia/Shanghai", 8*3600)), "JT808", MetricDailyTotalMileageKM, 12345.6, "km",
			12345.6, 12345.6, 13, "TOTAL_MILEAGE_DIFF", time.Date(2026, 7, 1, 22, 49, 11, 0, time.FixedZone("Asia/Shanghai", 8*3600)), time.Date(2026, 7, 1, 23, 9, 36, 0, time.FixedZone("Asia/Shanghai", 8*3600)),
		))

	repository := NewMetricRepository(db)
	rows, err := repository.Query(context.Background(), MetricQuery{
		VIN:      "LKLG7C4E3NA774736",
		Protocol: "JT808",
		DateFrom: "2026-07-01",
		DateTo:   "2026-07-01",
		Limit:    20,
	})
	if err != nil {
		t.Fatalf("Query() error = %v", err)
	}
	if len(rows) != 1 {
		t.Fatalf("row count = %d", len(rows))
	}
	if rows[0].MetricKey != MetricDailyTotalMileageKM || rows[0].MetricValue != 12345.6 {
		t.Fatalf("unexpected row: %#v", rows[0])
	}
	if rows[0].VehicleKey != "LKLG7C4E3NA774736" {
		t.Fatalf("vehicle key = %q", rows[0].VehicleKey)
	}
	if rows[0].StatDate != "2026-07-01" || rows[0].UpdatedAt != "2026-07-01 23:09:36" {
		t.Fatalf("unexpected time formatting: %#v", rows[0])
	}
	if err := mock.ExpectationsWereMet(); err != nil {
		t.Fatalf("sql expectations: %v", err)
	}
}

func TestMetricHandlerReturnsDailyMetrics(t *testing.T) {
	db, mock, err := sqlmock.New()
	if err != nil {
		t.Fatalf("sqlmock.New() error = %v", err)
	}
	defer db.Close()
	mock.ExpectQuery("SELECT COUNT\\(\\*\\) FROM vehicle_daily_metric").
		WithArgs("LB9A32A21R0LS1707", "GB32960", "2020-07-01", "2020-07-01").
		WillReturnRows(sqlmock.NewRows([]string{"total"}).AddRow(42))
	mock.ExpectQuery("SELECT vehicle_key, vin, stat_date, protocol, metric_key, metric_value, metric_unit, first_total_mileage_km, latest_total_mileage_km, sample_count, calculation_method, created_at, updated_at FROM vehicle_daily_metric").
		WithArgs("LB9A32A21R0LS1707", "GB32960", "2020-07-01", "2020-07-01", 50, 0).
		WillReturnRows(sqlmock.NewRows([]string{
			"vehicle_key", "vin", "stat_date", "protocol", "metric_key", "metric_value", "metric_unit",
			"first_total_mileage_km", "latest_total_mileage_km", "sample_count", "calculation_method",
			"created_at", "updated_at",
		}).AddRow(
			"LB9A32A21R0LS1707", "LB9A32A21R0LS1707", "2020-07-01", "GB32960", MetricDailyMileageKM, 0.0, "km",
			53490.9, 53490.9, 3, "TOTAL_MILEAGE_DIFF", "2026-07-01 22:07:58", "2026-07-01 22:28:25",
		))

	handler := NewMetricHandler(NewMetricRepository(db))
	request := httptest.NewRequest(http.MethodGet, "/api/stats/daily-metrics?vin=LB9A32A21R0LS1707&protocol=GB32960&dateFrom=2020-07-01&dateTo=2020-07-01", nil)
	response := httptest.NewRecorder()

	handler.ServeHTTP(response, request)

	if response.Code != http.StatusOK {
		t.Fatalf("status = %d body=%s", response.Code, response.Body.String())
	}
	body := response.Body.String()
	for _, want := range []string{`"vin":"LB9A32A21R0LS1707"`, `"metric_key":"daily_mileage_km"`, `"total":42`} {
		if !strings.Contains(body, want) {
			t.Fatalf("response missing %s: %s", want, body)
		}
	}
	if err := mock.ExpectationsWereMet(); err != nil {
		t.Fatalf("sql expectations: %v", err)
	}
}

func TestMetricHandlerFiltersByVehicleKey(t *testing.T) {
	db, mock, err := sqlmock.New()
	if err != nil {
		t.Fatalf("sqlmock.New() error = %v", err)
	}
	defer db.Close()
	mock.ExpectQuery("SELECT COUNT\\(\\*\\) FROM vehicle_daily_metric").
		WithArgs("JT808:013307811254", "JT808").
		WillReturnRows(sqlmock.NewRows([]string{"total"}).AddRow(12))
	mock.ExpectQuery("SELECT vehicle_key, vin, stat_date, protocol, metric_key, metric_value, metric_unit, first_total_mileage_km, latest_total_mileage_km, sample_count, calculation_method, created_at, updated_at FROM vehicle_daily_metric").
		WithArgs("JT808:013307811254", "JT808", 50, 0).
		WillReturnRows(sqlmock.NewRows([]string{
			"vehicle_key", "vin", "stat_date", "protocol", "metric_key", "metric_value", "metric_unit",
			"first_total_mileage_km", "latest_total_mileage_km", "sample_count", "calculation_method",
			"created_at", "updated_at",
		}).AddRow(
			"JT808:013307811254", "", "2026-07-02", "JT808", MetricDailyTotalMileageKM, 10985.7, "km",
			10985.7, 10985.7, 1, "TOTAL_MILEAGE_DIFF", "2026-07-02 00:03:00", "2026-07-02 00:03:00",
		))

	handler := NewMetricHandler(NewMetricRepository(db))
	request := httptest.NewRequest(http.MethodGet, "/api/stats/daily-metrics?vehicleKey=JT808:013307811254&protocol=JT808", nil)
	response := httptest.NewRecorder()

	handler.ServeHTTP(response, request)

	if response.Code != http.StatusOK {
		t.Fatalf("status = %d body=%s", response.Code, response.Body.String())
	}
	body := response.Body.String()
	for _, want := range []string{`"vehicle_key":"JT808:013307811254"`, `"vin":""`, `"metric_value":10985.7`} {
		if !strings.Contains(body, want) {
			t.Fatalf("response missing %s: %s", want, body)
		}
	}
	if err := mock.ExpectationsWereMet(); err != nil {
		t.Fatalf("sql expectations: %v", err)
	}
}

func TestMetricHandlerReturnsEmptyItemsArrayWhenNoRows(t *testing.T) {
	db, mock, err := sqlmock.New()
	if err != nil {
		t.Fatalf("sqlmock.New() error = %v", err)
	}
	defer db.Close()
	mock.ExpectQuery("SELECT COUNT\\(\\*\\) FROM vehicle_daily_metric").
		WithArgs("YUTONG_MQTT").
		WillReturnRows(sqlmock.NewRows([]string{"total"}).AddRow(0))
	mock.ExpectQuery("SELECT vehicle_key, vin, stat_date, protocol, metric_key, metric_value, metric_unit, first_total_mileage_km, latest_total_mileage_km, sample_count, calculation_method, created_at, updated_at FROM vehicle_daily_metric").
		WithArgs("YUTONG_MQTT", 50, 0).
		WillReturnRows(sqlmock.NewRows([]string{
			"vehicle_key", "vin", "stat_date", "protocol", "metric_key", "metric_value", "metric_unit",
			"first_total_mileage_km", "latest_total_mileage_km", "sample_count", "calculation_method",
			"created_at", "updated_at",
		}))

	handler := NewMetricHandler(NewMetricRepository(db))
	request := httptest.NewRequest(http.MethodGet, "/api/stats/daily-metrics?protocol=YUTONG_MQTT", nil)
	response := httptest.NewRecorder()

	handler.ServeHTTP(response, request)

	if response.Code != http.StatusOK {
		t.Fatalf("status = %d body=%s", response.Code, response.Body.String())
	}
	body := response.Body.String()
	if !strings.Contains(body, `"items":[]`) || strings.Contains(body, `"items":null`) {
		t.Fatalf("expected empty items array, got: %s", body)
	}
	if err := mock.ExpectationsWereMet(); err != nil {
		t.Fatalf("sql expectations: %v", err)
	}
}

func TestMetricHandlerRejectsInvalidPagination(t *testing.T) {
	handler := NewMetricHandler(NewMetricRepository(&sql.DB{}))
	request := httptest.NewRequest(http.MethodGet, "/api/stats/daily-metrics?limit=2001", nil)
	response := httptest.NewRecorder()

	handler.ServeHTTP(response, request)

	if response.Code != http.StatusBadRequest {
		t.Fatalf("status = %d body=%s", response.Code, response.Body.String())
	}
}