package controller

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

	"ezops/config"
	"ezops/model"

	"github.com/gin-gonic/gin"
	"github.com/glebarez/sqlite"
	"gorm.io/gorm"
)

// TestCurrencyExpression 验证 CNY 与 USD 报告币种使用同一组可逆汇率。 // Logan.Li
func TestCurrencyExpression(t *testing.T) {
	handler := NewBillingHandler(nil, &config.BillingConfig{
		BaseCurrency:  "CNY",
		ExchangeRates: map[string]float64{"cny": 1, "usd": 7.2},
	})
	_, cnyArgs, ok := handler.currencyExpression("CNY")
	if !ok || len(cnyArgs) != 2 {
		t.Fatalf("CNY 汇率表达式无效: ok=%v args=%v", ok, cnyArgs)
	}
	metadata := handler.reportCurrencyMetadata("USD")
	rates := metadata["exchange_rates"].(map[string]float64)
	if rates["USD"] != 1 || rates["CNY"] != 0.138889 {
		t.Fatalf("USD 折算汇率错误: %+v", rates)
	}
	if _, _, supported := handler.currencyExpression("EUR"); supported {
		t.Fatal("未配置币种不应被接受")
	}
}

// TestBillingCurrencyConversionAPI 验证统计接口不会直接混加不同原币金额。 // Logan.Li
func TestBillingCurrencyConversionAPI(t *testing.T) {
	gin.SetMode(gin.TestMode)
	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	if err != nil {
		t.Fatal(err)
	}
	if err := db.AutoMigrate(&model.CloudBilling{}, &model.BillingAlertRule{}); err != nil {
		t.Fatal(err)
	}
	today := time.Now().Format("2006-01-02")
	records := []model.CloudBilling{
		{Provider: "tencent", BillingDate: today, Cost: 100, Currency: "CNY", Service: "CVM"},
		{Provider: "aws", BillingDate: today, Cost: 10, Currency: "USD", Service: "EC2"},
	}
	if err := db.Create(&records).Error; err != nil {
		t.Fatal(err)
	}
	handler := NewBillingHandler(db, &config.BillingConfig{BaseCurrency: "CNY", ExchangeRates: map[string]float64{"CNY": 1, "USD": 7.2}})

	assertMonthCost := func(currency string, expected float64) {
		t.Helper()
		recorder := httptest.NewRecorder()
		context, _ := gin.CreateTestContext(recorder)
		context.Request = httptest.NewRequest("GET", "/?currency="+currency, nil)
		handler.GetBillingStats(context)
		var response struct {
			Code int `json:"code"`
			Data struct {
				MonthCost float64 `json:"month_cost"`
			} `json:"data"`
		}
		if err := json.Unmarshal(recorder.Body.Bytes(), &response); err != nil {
			t.Fatal(err)
		}
		if response.Code != 200 || mathRound(response.Data.MonthCost, 2) != expected {
			t.Fatalf("%s 月费用错误: code=%d cost=%f", currency, response.Code, response.Data.MonthCost)
		}
	}
	assertMonthCost("CNY", 172)
	assertMonthCost("USD", 23.89)
}

// TestBuildBillingAnalysisMonths 验证空月份补齐和非 Top 分类合并。 // Logan.Li
func TestBuildBillingAnalysisMonths(t *testing.T) {
	start, _ := time.Parse("2006-01", "2026-03")
	end, _ := time.Parse("2006-01", "2026-04")
	costs := map[string]map[string]float64{
		"2026-03": {"CVM": 100, "TCR": 20},
	}
	months := buildBillingAnalysisMonths(start, end, costs, []string{"CVM", "其他"})
	if len(months) != 2 || months[0].Total != 120 || months[0].Items[1].Cost != 20 {
		t.Fatalf("月度聚合错误: %+v", months)
	}
	if months[1].Month != "2026-04" || months[1].Total != 0 {
		t.Fatalf("空月份未正确补齐: %+v", months[1])
	}
}

// TestBuildBillingAttributions 验证归因变化额与贡献度。 // Logan.Li
func TestBuildBillingAttributions(t *testing.T) {
	items := buildBillingAttributions(map[string]float64{"CVM": 100}, map[string]float64{"CVM": 180, "TCR": 20})
	if len(items) != 2 || items[0].Name != "CVM" || items[0].Delta != 80 || items[0].Contribution != 80 {
		t.Fatalf("费用归因错误: %+v", items)
	}
}