package payment

import (
	"context"
	"encoding/json"
	"fmt"
)

// Service 支付业务层，内部封装 Client，对外暴露方法
type Service struct {
	client *Client
	cfg    Config
}

// NewService 创建支付服务
func NewService(cfg Config) *Service {
	return &Service{
		client: NewClient(cfg),
		cfg:    cfg,
	}
}

// GetClient 获取底层 HTTP 客户端（供高级用法）
func (s *Service) GetClient() *Client {
	return s.client
}

// Login 登录授权，获取 access_token
func (s *Service) Login(ctx context.Context) (map[string]any, error) {
	token, err := s.client.GetToken(ctx)
	if err != nil {
		return nil, err
	}
	return map[string]any{
		"success":     true,
		"access_token": token.AccessToken,
		"expires_in":  token.ExpiresIn,
		"message":     "授权成功",
	}, nil
}

// CheckAuth 查询授权状态
func (s *Service) CheckAuth(ctx context.Context) (map[string]any, error) {
	token, err := s.client.GetToken(ctx)
	if err != nil {
		return map[string]any{"success": false, "message": "授权失效，请重新登录"}, err
	}
	return map[string]any{
		"success":     true,
		"access_token": token.AccessToken,
		"expires_in":  token.ExpiresIn,
		"message":     "授权有效",
	}, nil
}

// Refresh 主动刷新令牌
func (s *Service) Refresh(ctx context.Context) (map[string]any, error) {
	token, err := s.client.RefreshToken(ctx)
	if err != nil {
		return nil, err
	}
	return map[string]any{
		"success":     true,
		"access_token": token.AccessToken,
		"expires_in":  token.ExpiresIn,
		"message":     "续期成功",
	}, nil
}

// GetAccountInfo 获取授权账号信息
func (s *Service) GetAccountInfo(ctx context.Context) (map[string]any, error) {
	raw, err := s.client.Get(ctx, "/v1/account/info", nil)
	if err != nil {
		return nil, fmt.Errorf("get account info: %w", err)
	}
	return parseAPIResponse(raw)
}

// QueryOrder 通过 order_id 查询订单
func (s *Service) QueryOrder(ctx context.Context, orderID string) (map[string]any, error) {
	raw, err := s.client.Get(ctx, "/v1/orders/"+orderID, nil)
	if err != nil {
		return nil, fmt.Errorf("query order: %w", err)
	}
	return parseAPIResponse(raw)
}

// QueryOrderByOutNo 通过商户订单号查询
func (s *Service) QueryOrderByOutNo(ctx context.Context, outTradeNo string) (map[string]any, error) {
	raw, err := s.client.Get(ctx, "/v1/orders", map[string]string{"out_trade_no": outTradeNo})
	if err != nil {
		return nil, fmt.Errorf("query order by out_no: %w", err)
	}
	return parseAPIResponse(raw)
}

// RequestRefund 申请退款
func (s *Service) RequestRefund(ctx context.Context, req map[string]any) (map[string]any, error) {
	raw, err := s.client.Post(ctx, "/v1/refunds", nil, req)
	if err != nil {
		return nil, fmt.Errorf("request refund: %w", err)
	}
	return parseAPIResponse(raw)
}

// GetBill 分页获取账单
func (s *Service) GetBill(ctx context.Context, page, pageSize int) (map[string]any, error) {
	params := map[string]string{
		"page":     fmt.Sprintf("%d", page),
		"page_size": fmt.Sprintf("%d", pageSize),
	}
	raw, err := s.client.Get(ctx, "/v1/bills", params)
	if err != nil {
		return nil, fmt.Errorf("get bill: %w", err)
	}
	return parseAPIResponse(raw)
}

// GetBillByDate 按日期范围查账单
func (s *Service) GetBillByDate(ctx context.Context, startDate, endDate string) (map[string]any, error) {
	params := map[string]string{
		"start_date": startDate,
		"end_date":   endDate,
	}
	raw, err := s.client.Get(ctx, "/v1/bills/range", params)
	if err != nil {
		return nil, fmt.Errorf("get bill by date: %w", err)
	}
	return parseAPIResponse(raw)
}

// ─────────────────────────────────────────────
// 内部辅助
// ─────────────────────────────────────────────

func parseAPIResponse(raw []byte) (map[string]any, error) {
	var result struct {
		Code    int         `json:"code"`
		Message string      `json:"message"`
		Data    interface{} `json:"data"`
	}
	if err := json.Unmarshal(raw, &result); err != nil {
		return nil, err
	}
	if result.Code != 0 {
		return nil, fmt.Errorf("api error code=%d msg=%s", result.Code, result.Message)
	}
	return map[string]any{"success": true, "data": result.Data, "message": result.Message}, nil
}