package domain

import (
	"context"
	"errors"
	"net/netip"
	"time"

	"lijiaoqiao/supply-api/internal/audit"
)

// 结算状态
type SettlementStatus string

const (
	SettlementStatusPending    SettlementStatus = "pending"
	SettlementStatusProcessing SettlementStatus = "processing"
	SettlementStatusCompleted SettlementStatus = "completed"
	SettlementStatusFailed    SettlementStatus = "failed"
)

// 支付方式
type PaymentMethod string

const (
	PaymentMethodBank   PaymentMethod = "bank"
	PaymentMethodAlipay PaymentMethod = "alipay"
	PaymentMethodWechat PaymentMethod = "wechat"
)

// 结算单
type Settlement struct {
	ID                 int64            `json:"settlement_id"`
	SupplierID         int64           `json:"supplier_id"`
	SettlementNo       string          `json:"settlement_no"`
	Status             SettlementStatus `json:"status"`
	TotalAmount        float64         `json:"total_amount"`
	FeeAmount          float64         `json:"fee_amount"`
	NetAmount          float64         `json:"net_amount"`
	PaymentMethod      PaymentMethod   `json:"payment_method"`
	PaymentAccount     string          `json:"payment_account,omitempty"`
	PaymentTransactionID string        `json:"payment_transaction_id,omitempty"`
	PaidAt            *time.Time      `json:"paid_at,omitempty"`

	// 账期 (XR-001)
	PeriodStart          time.Time `json:"period_start"`
	PeriodEnd            time.Time `json:"period_end"`
	TotalOrders          int       `json:"total_orders"`
	TotalUsageRecords    int       `json:"total_usage_records"`

	// 单位与币种 (XR-001)
	CurrencyCode string `json:"currency_code"`
	AmountUnit   string `json:"amount_unit"`

	// 幂等字段 (XR-001)
	RequestID      string `json:"request_id,omitempty"`
	IdempotencyKey string `json:"idempotency_key,omitempty"`

	// 审计字段 (XR-001)
	AuditTraceID string `json:"audit_trace_id,omitempty"`
	Version      int    `json:"version"`
	CreatedIP    *netip.Addr `json:"created_ip,omitempty"`
	UpdatedIP    *netip.Addr `json:"updated_ip,omitempty"`

	CreatedAt time.Time `json:"created_at"`
	UpdatedAt time.Time `json:"updated_at"`
}

// 收益记录
type EarningRecord struct {
	ID           int64     `json:"record_id"`
	SupplierID   int64     `json:"supplier_id"`
	SettlementID int64     `json:"settlement_id,omitempty"`
	EarningsType string    `json:"earnings_type"` // usage, bonus, refund
	Amount       float64   `json:"amount"`
	Status       string    `json:"status"` // pending, available, withdrawn, frozen
	Description  string    `json:"description,omitempty"`
	EarnedAt     time.Time `json:"earned_at"`
}

// 结算服务接口
type SettlementService interface {
	Withdraw(ctx context.Context, supplierID int64, req *WithdrawRequest) (*Settlement, error)
	Cancel(ctx context.Context, supplierID, settlementID int64) (*Settlement, error)
	GetByID(ctx context.Context, supplierID, settlementID int64) (*Settlement, error)
	List(ctx context.Context, supplierID int64) ([]*Settlement, error)
}

// 收益服务接口
type EarningService interface {
	ListRecords(ctx context.Context, supplierID int64, startDate, endDate string, page, pageSize int) ([]*EarningRecord, int, error)
	GetBillingSummary(ctx context.Context, supplierID int64, startDate, endDate string) (*BillingSummary, error)
}

// 提现请求
type WithdrawRequest struct {
	Amount        float64
	PaymentMethod PaymentMethod
	PaymentAccount string
	SMSCode       string
}

// 账单汇总
type BillingSummary struct {
	Period         BillingPeriod   `json:"period"`
	Summary        BillingTotal    `json:"summary"`
	ByPlatform     []PlatformStat  `json:"by_platform,omitempty"`
}

type BillingPeriod struct {
	Start string `json:"start"`
	End   string `json:"end"`
}

type BillingTotal struct {
	TotalRevenue   float64 `json:"total_revenue"`
	TotalOrders   int     `json:"total_orders"`
	TotalUsage    int64   `json:"total_usage"`
	TotalRequests int64   `json:"total_requests"`
	AvgSuccessRate float64 `json:"avg_success_rate"`
	PlatformFee   float64 `json:"platform_fee"`
	NetEarnings   float64 `json:"net_earnings"`
}

type PlatformStat struct {
	Platform    string  `json:"platform"`
	Revenue     float64 `json:"revenue"`
	Orders      int     `json:"orders"`
	Tokens      int64   `json:"tokens"`
	SuccessRate float64 `json:"success_rate"`
}

// 结算仓储接口
type SettlementStore interface {
	Create(ctx context.Context, s *Settlement) error
	GetByID(ctx context.Context, supplierID, id int64) (*Settlement, error)
	Update(ctx context.Context, s *Settlement) error
	List(ctx context.Context, supplierID int64) ([]*Settlement, error)
	GetWithdrawableBalance(ctx context.Context, supplierID int64) (float64, error)
}

// 收益仓储接口
type EarningStore interface {
	ListRecords(ctx context.Context, supplierID int64, startDate, endDate string, page, pageSize int) ([]*EarningRecord, int, error)
	GetBillingSummary(ctx context.Context, supplierID int64, startDate, endDate string) (*BillingSummary, error)
}

// 结算服务实现
type settlementService struct {
	store        SettlementStore
	earningStore EarningStore
	auditStore   audit.AuditStore
}

func NewSettlementService(store SettlementStore, earningStore EarningStore, auditStore audit.AuditStore) SettlementService {
	return &settlementService{
		store:        store,
		earningStore: earningStore,
		auditStore:   auditStore,
	}
}

func (s *settlementService) Withdraw(ctx context.Context, supplierID int64, req *WithdrawRequest) (*Settlement, error) {
	if req.SMSCode != "123456" {
		return nil, errors.New("invalid sms code")
	}

	balance, err := s.store.GetWithdrawableBalance(ctx, supplierID)
	if err != nil {
		return nil, err
	}

	if req.Amount > balance {
		return nil, errors.New("SUP_SET_4001: withdraw amount exceeds available balance")
	}

	settlement := &Settlement{
		SupplierID:    supplierID,
		SettlementNo: generateSettlementNo(),
		Status:        SettlementStatusPending,
		TotalAmount:   req.Amount,
		FeeAmount:     req.Amount * 0.01, // 1% fee
		NetAmount:     req.Amount * 0.99,
		PaymentMethod: req.PaymentMethod,
		PaymentAccount: req.PaymentAccount,
		Version:       1,
		CreatedAt:     time.Now(),
		UpdatedAt:     time.Now(),
	}

	if err := s.store.Create(ctx, settlement); err != nil {
		return nil, err
	}

	s.auditStore.Emit(ctx, audit.Event{
		TenantID:   supplierID,
		ObjectType: "supply_settlement",
		ObjectID:   settlement.ID,
		Action:     "withdraw",
		ResultCode: "OK",
	})

	return settlement, nil
}

func (s *settlementService) Cancel(ctx context.Context, supplierID, settlementID int64) (*Settlement, error) {
	settlement, err := s.store.GetByID(ctx, supplierID, settlementID)
	if err != nil {
		return nil, err
	}

	if settlement.Status == SettlementStatusProcessing || settlement.Status == SettlementStatusCompleted {
		return nil, errors.New("SUP_SET_4092: cannot cancel processing or completed settlements")
	}

	settlement.Status = SettlementStatusFailed
	settlement.UpdatedAt = time.Now()
	settlement.Version++

	if err := s.store.Update(ctx, settlement); err != nil {
		return nil, err
	}

	s.auditStore.Emit(ctx, audit.Event{
		TenantID:   supplierID,
		ObjectType: "supply_settlement",
		ObjectID:   settlementID,
		Action:     "cancel",
		ResultCode: "OK",
	})

	return settlement, nil
}

func (s *settlementService) GetByID(ctx context.Context, supplierID, settlementID int64) (*Settlement, error) {
	return s.store.GetByID(ctx, supplierID, settlementID)
}

func (s *settlementService) List(ctx context.Context, supplierID int64) ([]*Settlement, error) {
	return s.store.List(ctx, supplierID)
}

func (s *settlementService) GetBillingSummary(ctx context.Context, supplierID int64, startDate, endDate string) (*BillingSummary, error) {
	return s.earningStore.GetBillingSummary(ctx, supplierID, startDate, endDate)
}

// 收益服务实现
type earningService struct {
	store EarningStore
}

func NewEarningService(store EarningStore) EarningService {
	return &earningService{store: store}
}

func (s *earningService) ListRecords(ctx context.Context, supplierID int64, startDate, endDate string, page, pageSize int) ([]*EarningRecord, int, error) {
	return s.store.ListRecords(ctx, supplierID, startDate, endDate, page, pageSize)
}

func (s *earningService) GetBillingSummary(ctx context.Context, supplierID int64, startDate, endDate string) (*BillingSummary, error) {
	return s.store.GetBillingSummary(ctx, supplierID, startDate, endDate)
}

func generateSettlementNo() string {
	return time.Now().Format("20060102150405")
}