package cloud

import (
	"encoding/json"
	"fmt"
	"math"
	"sort"
	"strconv"
	"strings"
	"time"
)

// FetchDailyBill 通过 Azure Cost Management Query 拉取订阅单日成本。 // Logan.Li
func (p *AzureProvider) FetchDailyBill(billingDate string) ([]CloudBillingRecord, error) {
	start, err := time.Parse("2006-01-02", billingDate)
	if err != nil {
		return nil, fmt.Errorf("账单日期格式应为 YYYY-MM-DD")
	}
	if p.subscriptionID == "" {
		return nil, fmt.Errorf("Azure AccessKey 应为 租户ID:订阅ID:客户端ID")
	}
	payload := map[string]interface{}{
		"type":      "ActualCost",
		"timeframe": "Custom",
		"timePeriod": map[string]string{
			"from": start.Format("2006-01-02T00:00:00Z"),
			"to":   start.AddDate(0, 0, 1).Format("2006-01-02T00:00:00Z"),
		},
		"dataset": map[string]interface{}{
			"granularity": "Daily",
			"aggregation": map[string]interface{}{
				"totalCost": map[string]string{"name": "PreTaxCost", "function": "Sum"},
			},
			"grouping": []map[string]string{
				{"type": "Dimension", "name": "ServiceName"},
				{"type": "Dimension", "name": "ResourceLocation"},
			},
		},
	}
	path := "/subscriptions/" + p.subscriptionID + "/providers/Microsoft.CostManagement/query?api-version=2023-11-01"
	body, err := p.post(path, payload)
	if err != nil {
		return nil, err
	}
	var response struct {
		Properties struct {
			Columns []struct {
				Name string `json:"name"`
			} `json:"columns"`
			Rows [][]interface{} `json:"rows"`
		} `json:"properties"`
	}
	if err = json.Unmarshal(body, &response); err != nil {
		return nil, fmt.Errorf("解析 Azure Cost Management 响应失败: %w", err)
	}
	columnIndex := map[string]int{}
	for index, column := range response.Properties.Columns {
		columnIndex[strings.ToLower(column.Name)] = index
	}
	valueAt := func(row []interface{}, names ...string) interface{} {
		for _, name := range names {
			if index, ok := columnIndex[strings.ToLower(name)]; ok && index < len(row) {
				return row[index]
			}
		}
		return nil
	}
	type aggregationKey struct {
		service string
		region  string
	}
	aggregation := map[aggregationKey]float64{}
	currency := "USD"
	for _, row := range response.Properties.Rows {
		cost, _ := strconv.ParseFloat(fmt.Sprint(valueAt(row, "PreTaxCost", "Cost", "totalCost")), 64)
		if cost == 0 {
			continue
		}
		service := firstNonEmpty(fmt.Sprint(valueAt(row, "ServiceName")), "其他")
		region := firstNonEmpty(fmt.Sprint(valueAt(row, "ResourceLocation")), "全局")
		if value := fmt.Sprint(valueAt(row, "Currency")); value != "" && value != "<nil>" {
			currency = value
		}
		aggregation[aggregationKey{service: service, region: region}] += cost
	}
	keys := make([]aggregationKey, 0, len(aggregation))
	for key := range aggregation {
		keys = append(keys, key)
	}
	sort.Slice(keys, func(i, j int) bool {
		if keys[i].service == keys[j].service {
			return keys[i].region < keys[j].region
		}
		return keys[i].service < keys[j].service
	})
	records := make([]CloudBillingRecord, 0, len(keys))
	for _, key := range keys {
		records = append(records, CloudBillingRecord{
			BillingDate: billingDate, Provider: "azure", Cost: math.Round(aggregation[key]*1000000) / 1000000,
			Currency: currency, Service: key.service, Region: key.region,
			Description: "云 API 自动同步（Azure Cost Management）",
		})
	}
	return records, nil
}