package mysql

import (
	"context"
	"fmt"
	"strings"
	"time"

	"hyapp/pkg/appcode"
	"hyapp/pkg/xerr"
	"hyapp/services/wallet-service/internal/domain/ledger"
)

// FreezeSalaryWithdrawal 在同一事务里把工资 available 转入 frozen，并落交易、分录和余额 outbox。
func (r *Repository) FreezeSalaryWithdrawal(ctx context.Context, command ledger.SalaryWithdrawalCommand) (ledger.SalaryWithdrawalReceipt, error) {
	return r.applySalaryWithdrawal(ctx, command, salaryWithdrawalMutation{
		BizType:        bizTypeSalaryWithdrawalFreeze,
		AvailableDelta: -command.SalaryUSDMinor,
		FrozenDelta:    command.SalaryUSDMinor,
		ExternalRef:    command.WithdrawalRef,
	})
}

// SettleSalaryWithdrawal 在审核通过时只扣 frozen；这保证提交申请时已经冻结的金额不会被重复扣 available。
func (r *Repository) SettleSalaryWithdrawal(ctx context.Context, command ledger.SalaryWithdrawalCommand) (ledger.SalaryWithdrawalReceipt, error) {
	return r.applySalaryWithdrawal(ctx, command, salaryWithdrawalMutation{
		BizType:        bizTypeSalaryWithdrawalSettle,
		AvailableDelta: 0,
		FrozenDelta:    -command.SalaryUSDMinor,
		ExternalRef:    command.WithdrawalApplicationID,
	})
}

// ReleaseSalaryWithdrawal 在拒绝或创建申请失败回滚时把 frozen 返还 available。
func (r *Repository) ReleaseSalaryWithdrawal(ctx context.Context, command ledger.SalaryWithdrawalCommand) (ledger.SalaryWithdrawalReceipt, error) {
	return r.applySalaryWithdrawal(ctx, command, salaryWithdrawalMutation{
		BizType:        bizTypeSalaryWithdrawalRelease,
		AvailableDelta: command.SalaryUSDMinor,
		FrozenDelta:    -command.SalaryUSDMinor,
		ExternalRef:    command.WithdrawalApplicationID,
	})
}

type salaryWithdrawalMutation struct {
	BizType        string
	AvailableDelta int64
	FrozenDelta    int64
	ExternalRef    string
}

func (r *Repository) applySalaryWithdrawal(ctx context.Context, command ledger.SalaryWithdrawalCommand, mutation salaryWithdrawalMutation) (ledger.SalaryWithdrawalReceipt, error) {
	if r == nil || r.db == nil {
		return ledger.SalaryWithdrawalReceipt{}, xerr.New(xerr.Unavailable, "mysql repository is not configured")
	}
	ctx = contextWithCommandApp(ctx, command.AppCode)
	command.AppCode = appcode.FromContext(ctx)

	tx, err := r.db.BeginTx(ctx, nil)
	if err != nil {
		return ledger.SalaryWithdrawalReceipt{}, err
	}
	defer func() { _ = tx.Rollback() }()

	requestHash := salaryWithdrawalRequestHash(command, mutation.BizType)
	if txRow, exists, err := r.lookupTransactionWithConflictCode(ctx, tx, command.CommandID, requestHash, mutation.BizType, xerr.IdempotencyConflict); err != nil || exists {
		if err != nil || !exists {
			return ledger.SalaryWithdrawalReceipt{}, err
		}
		return r.receiptForSalaryWithdrawalTransaction(ctx, tx, txRow.TransactionID)
	}

	nowMs := time.Now().UTC().UnixMilli()
	account, err := r.lockAccount(ctx, tx, command.UserID, command.SalaryAssetType, false, nowMs)
	if err != nil {
		return ledger.SalaryWithdrawalReceipt{}, err
	}
	if account.AvailableAmount+mutation.AvailableDelta < 0 || account.FrozenAmount+mutation.FrozenDelta < 0 {
		return ledger.SalaryWithdrawalReceipt{}, xerr.New(xerr.InsufficientBalance, "insufficient balance")
	}

	transactionID := transactionID(command.AppCode, command.CommandID)
	availableAfter := account.AvailableAmount + mutation.AvailableDelta
	frozenAfter := account.FrozenAmount + mutation.FrozenDelta
	metadata := salaryWithdrawalMetadata{
		AppCode:                 command.AppCode,
		UserID:                  command.UserID,
		SalaryAssetType:         command.SalaryAssetType,
		SalaryUSDMinor:          command.SalaryUSDMinor,
		PointFeeAmount:          command.PointFeeAmount,
		PointNetAmount:          command.PointNetAmount,
		PointsPerUSD:            command.PointsPerUSD,
		PointWithdrawFeeBPS:     command.PointWithdrawFeeBPS,
		OperatorUserID:          command.OperatorUserID,
		Reason:                  command.Reason,
		WithdrawalRef:           command.WithdrawalRef,
		WithdrawalApplicationID: command.WithdrawalApplicationID,
		AvailableAfter:          availableAfter,
		FrozenAfter:             frozenAfter,
		Version:                 account.Version + 1,
		CreatedAtMS:             nowMs,
	}
	if err := r.insertTransaction(ctx, tx, transactionID, command.CommandID, mutation.BizType, requestHash, strings.TrimSpace(mutation.ExternalRef), metadata, nowMs); err != nil {
		return ledger.SalaryWithdrawalReceipt{}, err
	}
	if err := r.applyAccountDelta(ctx, tx, account, mutation.AvailableDelta, mutation.FrozenDelta, nowMs); err != nil {
		return ledger.SalaryWithdrawalReceipt{}, err
	}
	if err := r.insertEntry(ctx, tx, walletEntry{
		TransactionID:  transactionID,
		UserID:         command.UserID,
		AssetType:      command.SalaryAssetType,
		AvailableDelta: mutation.AvailableDelta,
		FrozenDelta:    mutation.FrozenDelta,
		AvailableAfter: availableAfter,
		FrozenAfter:    frozenAfter,
		CreatedAtMS:    nowMs,
	}); err != nil {
		return ledger.SalaryWithdrawalReceipt{}, err
	}
	if err := r.insertWalletOutbox(ctx, tx, []walletOutboxEvent{
		balanceChangedEvent(transactionID, command.CommandID, command.UserID, command.SalaryAssetType, mutation.AvailableDelta, mutation.FrozenDelta, availableAfter, frozenAfter, account.Version+1, metadata, nowMs, mutation.BizType),
	}); err != nil {
		return ledger.SalaryWithdrawalReceipt{}, err
	}
	if err := tx.Commit(); err != nil {
		return ledger.SalaryWithdrawalReceipt{}, err
	}
	return receiptFromSalaryWithdrawalMetadata(transactionID, metadata), nil
}

func salaryWithdrawalRequestHash(command ledger.SalaryWithdrawalCommand, bizType string) string {
	return stableHash(fmt.Sprintf("salary_withdrawal|%s|%s|%d|%s|%d|%d|%d|%d|%d|%d|%s|%s|%s",
		bizType,
		appcode.Normalize(command.AppCode),
		command.UserID,
		strings.ToUpper(strings.TrimSpace(command.SalaryAssetType)),
		command.SalaryUSDMinor,
		command.PointFeeAmount,
		command.PointNetAmount,
		command.PointsPerUSD,
		command.PointWithdrawFeeBPS,
		command.OperatorUserID,
		strings.TrimSpace(command.Reason),
		strings.TrimSpace(command.WithdrawalRef),
		strings.TrimSpace(command.WithdrawalApplicationID),
	))
}