// Package agentrecharge 收口员工线下代充值申请和审批终态业务用例。
package agentrecharge

import (
	"context"
	"fmt"
	"strings"

	"github.com/bytedance/sonic"
	"gorm.io/gorm"
	"gorm.io/gorm/clause"

	approvalapp "github.com/break/junhong_cmp_fiber/internal/application/approval"
	"github.com/break/junhong_cmp_fiber/internal/model"
	"github.com/break/junhong_cmp_fiber/pkg/constants"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
)

// CreateOfflineCommand 描述员工创建线下代充值审批申请的稳定输入。
type CreateOfflineCommand struct {
	SubmitterAccountID uint
	SubmitterUserType  int
	ShopID             uint
	RechargeNo         string
	Amount             int64
	PaymentVoucherKeys []string
	OtherVoucherKeys   []string
	// OfflinePaymentMethodID 是提交人选择的线下收款方式字典项 ID。
	OfflinePaymentMethodID uint
	// ExternalTransactionNo 是人工确认后的交易流水号，独立于在线渠道第三方交易号。
	ExternalTransactionNo string
	Remark                string
}

// CreateOfflineResult 返回已原子保存的业务申请和初始审批状态。
type CreateOfflineResult struct {
	Record         *model.AgentRechargeRecord
	ShopName       string
	SubmitterName  string
	ApprovalStatus int
}

// OfflineCreationService 创建员工线下代充值申请及唯一通用审批实例。
type OfflineCreationService struct {
	db       *gorm.DB
	approval approvalapp.Port
	audit    RechargeAuditWriter
}

// NewOfflineCreationService 创建员工线下代充值申请用例。
func NewOfflineCreationService(db *gorm.DB, approval approvalapp.Port, audit RechargeAuditWriter) *OfflineCreationService {
	return &OfflineCreationService{db: db, approval: approval, audit: audit}
}

// TriggerHistorical 为历史待审批线下代充值补发一次企业微信审批。
func (s *OfflineCreationService) TriggerHistorical(ctx context.Context, recordID uint) (*CreateOfflineResult, error) {
	if s == nil || s.db == nil || s.approval == nil || s.audit == nil || recordID == 0 {
		return nil, errors.New(errors.CodeServiceUnavailable, "员工线下代充值审批能力未配置")
	}

	var record model.AgentRechargeRecord
	if err := s.db.WithContext(ctx).First(&record, recordID).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, errors.New(errors.CodeNotFound, "充值记录不存在")
		}
		return nil, errors.Wrap(errors.CodeDatabaseError, err, "查询历史线下代充值申请失败")
	}
	if record.PaymentMethod != constants.RechargeMethodOffline || record.Status != constants.RechargeStatusPending || record.ApprovalInstanceID != nil {
		return nil, errors.New(errors.CodeConflict, "充值申请状态不允许补发审批")
	}
	account, shop, wallet, err := s.loadHistoricalFacts(ctx, &record)
	if err != nil {
		return nil, err
	}
	preparation, err := s.approval.Prepare(ctx, approvalapp.PrepareRequest{
		BusinessType: constants.ApprovalBusinessTypeOfflineRecharge, SubmitterAccountID: record.UserID,
		CorrelationID: record.RechargeNo,
	})
	if err != nil {
		return nil, err
	}
	command := CreateOfflineCommand{
		SubmitterAccountID: record.UserID, SubmitterUserType: account.UserType, ShopID: record.ShopID,
		RechargeNo: record.RechargeNo, Amount: record.Amount,
		PaymentVoucherKeys: []string(record.PaymentVoucherKey), Remark: record.Remark,
		OtherVoucherKeys: []string(record.OtherVoucherKeys),
	}
	if record.ExternalTransactionNo != nil {
		command.ExternalTransactionNo = *record.ExternalTransactionNo
	}
	// 补发审批使用历史记录已冻结的收款方式快照，不回查当前字典，避免历史材料被字典变更改写。
	var frozenCode, frozenName string
	if record.OfflinePaymentMethodCode != nil {
		frozenCode = *record.OfflinePaymentMethodCode
	}
	if record.OfflinePaymentMethodName != nil {
		frozenName = *record.OfflinePaymentMethodName
	}
	submitterSnapshot, requestSnapshot, err := offlineApprovalSnapshots(command, account.Username, shop.ShopName, frozenCode, frozenName)
	if err != nil {
		return nil, err
	}

	var approvalStatus int
	err = s.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		var current model.AgentRechargeRecord
		if err := tx.WithContext(ctx).Clauses(clause.Locking{Strength: "UPDATE"}).First(&current, recordID).Error; err != nil {
			if err == gorm.ErrRecordNotFound {
				return errors.New(errors.CodeNotFound, "充值记录不存在")
			}
			return errors.Wrap(errors.CodeDatabaseError, err, "锁定历史线下代充值申请失败")
		}
		if current.PaymentMethod != constants.RechargeMethodOffline || current.Status != constants.RechargeStatusPending || current.ApprovalInstanceID != nil {
			return errors.New(errors.CodeConflict, "充值申请状态不允许补发审批")
		}
		reference, err := s.approval.CreateInTx(ctx, tx, approvalapp.CreateRequest{
			Preparation: preparation, BusinessType: constants.ApprovalBusinessTypeOfflineRecharge,
			BusinessID: current.ID, SubmitterAccountID: current.UserID,
			SubmitterSnapshot: submitterSnapshot, RequestSnapshot: requestSnapshot,
			CorrelationID: current.RechargeNo,
		})
		if err != nil {
			return err
		}
		result := tx.WithContext(ctx).Model(&model.AgentRechargeRecord{}).
			Where("id = ? AND payment_method = ? AND status = ? AND approval_instance_id IS NULL", current.ID, constants.RechargeMethodOffline, constants.RechargeStatusPending).
			Update("approval_instance_id", reference.InstanceID)
		if result.Error != nil {
			return errors.Wrap(errors.CodeDatabaseError, result.Error, "关联线下代充值审批实例失败")
		}
		if result.RowsAffected != 1 {
			return errors.New(errors.CodeConflict, "线下代充值审批实例关联已变化")
		}
		current.ApprovalInstanceID = &reference.InstanceID
		record = current
		approvalStatus = reference.Status
		var instance model.ApprovalInstance
		if err := tx.WithContext(ctx).First(&instance, reference.InstanceID).Error; err != nil {
			return errors.Wrap(errors.CodeDatabaseError, err, "查询线下代充值审批审计快照失败")
		}
		return s.audit.WriteAgentRecharge(ctx, tx, RechargeAudit{
			ActionCode: constants.AuditActionAgentRechargeCreated, Summary: "补发员工线下代充值审批",
			Record: &current, Approval: &instance, Wallet: wallet,
			AfterData: map[string]any{"status": current.Status, "approval_instance_id": current.ApprovalInstanceID},
		})
	})
	if err != nil {
		return nil, err
	}
	return &CreateOfflineResult{
		Record: &record, ShopName: shop.ShopName, SubmitterName: account.Username, ApprovalStatus: approvalStatus,
	}, nil
}

// Execute 在业务写入前校验审批渠道，并在同一事务保存充值申请、审批实例和提交 Outbox。
func (s *OfflineCreationService) Execute(ctx context.Context, command CreateOfflineCommand) (*CreateOfflineResult, error) {
	if s == nil || s.db == nil || s.approval == nil || s.audit == nil {
		return nil, errors.New(errors.CodeServiceUnavailable, "员工线下代充值审批能力未配置")
	}
	if err := validateCreateOfflineCommand(command); err != nil {
		return nil, err
	}
	account, shop, wallet, err := s.loadCreationFacts(ctx, command)
	if err != nil {
		return nil, err
	}
	preparation, err := s.approval.Prepare(ctx, approvalapp.PrepareRequest{
		BusinessType: constants.ApprovalBusinessTypeOfflineRecharge, SubmitterAccountID: command.SubmitterAccountID,
		CorrelationID: strings.TrimSpace(command.RechargeNo),
	})
	if err != nil {
		return nil, err
	}
	paymentChannel := constants.RechargeMethodOffline
	externalTransactionNo := strings.TrimSpace(command.ExternalTransactionNo)
	var record *model.AgentRechargeRecord
	var approvalStatus int
	err = s.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		paymentMethod, err := loadEnabledOfflinePaymentMethod(ctx, tx, command.OfflinePaymentMethodID)
		if err != nil {
			return err
		}
		submitterSnapshot, requestSnapshot, err := offlineApprovalSnapshots(command, account.Username, shop.ShopName, paymentMethod.Code, paymentMethod.Name)
		if err != nil {
			return err
		}
		record = &model.AgentRechargeRecord{
			UserID: command.SubmitterAccountID, AgentWalletID: wallet.ID, ShopID: command.ShopID,
			RechargeNo: strings.TrimSpace(command.RechargeNo), Amount: command.Amount,
			PaymentMethod: constants.RechargeMethodOffline, PaymentChannel: &paymentChannel,
			PaymentVoucherKey: model.StringJSONBArray(command.PaymentVoucherKeys), Remark: strings.TrimSpace(command.Remark),
			ExternalTransactionNo:    &externalTransactionNo,
			OfflinePaymentMethodID:   &paymentMethod.ID,
			OfflinePaymentMethodCode: &paymentMethod.Code,
			OfflinePaymentMethodName: &paymentMethod.Name,
			OtherVoucherKeys:         model.StringJSONBArray(command.OtherVoucherKeys),
			Status:                   constants.RechargeStatusPending, ShopIDTag: wallet.ShopIDTag, EnterpriseIDTag: wallet.EnterpriseIDTag,
		}
		if err := tx.WithContext(ctx).Create(record).Error; err != nil {
			return errors.Wrap(errors.CodeDatabaseError, err, "创建员工线下代充值申请失败")
		}
		reference, err := s.approval.CreateInTx(ctx, tx, approvalapp.CreateRequest{
			Preparation: preparation, BusinessType: constants.ApprovalBusinessTypeOfflineRecharge,
			BusinessID: record.ID, SubmitterAccountID: command.SubmitterAccountID,
			SubmitterSnapshot: submitterSnapshot, RequestSnapshot: requestSnapshot,
			CorrelationID: record.RechargeNo,
		})
		if err != nil {
			return err
		}
		result := tx.WithContext(ctx).Model(&model.AgentRechargeRecord{}).
			Where("id = ? AND approval_instance_id IS NULL", record.ID).
			Update("approval_instance_id", reference.InstanceID)
		if result.Error != nil {
			return errors.Wrap(errors.CodeDatabaseError, result.Error, "关联员工线下代充值审批实例失败")
		}
		if result.RowsAffected != 1 {
			return errors.New(errors.CodeConflict, "员工线下代充值审批实例关联已变化")
		}
		record.ApprovalInstanceID = &reference.InstanceID
		approvalStatus = reference.Status
		var instance model.ApprovalInstance
		if err := tx.WithContext(ctx).First(&instance, reference.InstanceID).Error; err != nil {
			return errors.Wrap(errors.CodeDatabaseError, err, "查询线下代充值审批审计快照失败")
		}
		return s.audit.WriteAgentRecharge(ctx, tx, RechargeAudit{
			ActionCode: constants.AuditActionAgentRechargeCreated, Summary: "创建员工线下代充值申请",
			Record: record, Approval: &instance, Wallet: wallet, AfterData: map[string]any{"status": record.Status},
		})
	})
	if err != nil {
		return nil, err
	}
	return &CreateOfflineResult{
		Record: record, ShopName: shop.ShopName, SubmitterName: account.Username, ApprovalStatus: approvalStatus,
	}, nil
}

func validateCreateOfflineCommand(command CreateOfflineCommand) error {
	if command.SubmitterUserType != constants.UserTypePlatform && command.SubmitterUserType != constants.UserTypeSuperAdmin {
		return errors.New(errors.CodeForbidden, "线下充值仅平台管理员可操作")
	}
	if command.SubmitterAccountID == 0 || command.ShopID == 0 || strings.TrimSpace(command.RechargeNo) == "" {
		return errors.New(errors.CodeInvalidParam)
	}
	if command.Amount < constants.AgentRechargeMinAmount || command.Amount > constants.AgentRechargeMaxAmount {
		return errors.New(errors.CodeInvalidParam, "充值金额超出允许范围")
	}
	if command.OfflinePaymentMethodID == 0 {
		return errors.New(errors.CodeInvalidParam, "线下充值必须选择线下收款方式")
	}
	if err := validateRechargeTransactionNo(command.ExternalTransactionNo); err != nil {
		return err
	}
	if err := validateVoucherKeys(command.PaymentVoucherKeys, 1, constants.AgentRechargePaymentVoucherMaxCount, "线下充值必须上传 1 至 5 个支付凭证"); err != nil {
		return err
	}
	return validateVoucherKeys(command.OtherVoucherKeys, 0, constants.AgentRechargeOtherVoucherMaxCount, "线下充值其他凭证最多 5 个")
}

// validateRechargeTransactionNo 校验交易流水号必填且不超过长度上限；不参与去重与幂等判定。
func validateRechargeTransactionNo(value string) error {
	trimmed := strings.TrimSpace(value)
	if trimmed == "" {
		return errors.New(errors.CodeInvalidParam, "线下充值必须填写交易流水号")
	}
	if len([]rune(trimmed)) > constants.AgentRechargeExternalTransactionNoMaxLength {
		return errors.New(errors.CodeInvalidParam, "交易流水号长度超出限制")
	}
	return nil
}

// validateVoucherKeys 校验凭证对象键数量与内容，minCount 为 0 时允许为空。
func validateVoucherKeys(keys []string, minCount, maxCount int, message string) error {
	if len(keys) < minCount || len(keys) > maxCount {
		return errors.New(errors.CodeInvalidParam, message)
	}
	seen := make(map[string]struct{}, len(keys))
	for _, key := range keys {
		trimmed := strings.TrimSpace(key)
		if trimmed == "" {
			return errors.New(errors.CodeInvalidParam, "线下充值凭证对象键不能为空")
		}
		if len([]rune(trimmed)) > constants.AgentRechargeVoucherKeyMaxLength {
			return errors.New(errors.CodeInvalidParam, "线下充值凭证对象键长度超出限制")
		}
		if _, exists := seen[trimmed]; exists {
			return errors.New(errors.CodeInvalidParam, "线下充值凭证对象键不能重复")
		}
		seen[trimmed] = struct{}{}
	}
	return nil
}

// loadEnabledOfflinePaymentMethod 读取启用的线下收款方式字典项；不存在或已停用一律拒绝。
// 仅校验存在性与启停，不做编码或名称的二次改写，快照以字典当前值为准。
func loadEnabledOfflinePaymentMethod(ctx context.Context, tx *gorm.DB, id uint) (*model.EmployeeCollectionPaymentMethod, error) {
	if id == 0 {
		return nil, errors.New(errors.CodeInvalidParam, "线下充值必须选择线下收款方式")
	}
	var paymentMethod model.EmployeeCollectionPaymentMethod
	if err := tx.WithContext(ctx).First(&paymentMethod, id).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, errors.New(errors.CodeEmployeeCollectionPaymentMethodNotFound)
		}
		return nil, errors.Wrap(errors.CodeDatabaseError, err, "查询线下收款方式失败")
	}
	if paymentMethod.Status != constants.EmployeeCollectionPaymentMethodStatusEnabled {
		return nil, errors.New(errors.CodeEmployeeCollectionPaymentMethodDisabled)
	}
	return &paymentMethod, nil
}

func (s *OfflineCreationService) loadHistoricalFacts(
	ctx context.Context, record *model.AgentRechargeRecord,
) (*model.Account, *model.Shop, *model.AgentWallet, error) {
	if record == nil || record.UserID == 0 || record.ShopID == 0 || record.AgentWalletID == 0 {
		return nil, nil, nil, errors.New(errors.CodeInvalidParam)
	}
	var account model.Account
	if err := s.db.WithContext(ctx).Where("id = ? AND status = ?", record.UserID, constants.StatusEnabled).First(&account).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, nil, nil, errors.New(errors.CodeForbidden, "原创建账号不可用")
		}
		return nil, nil, nil, errors.Wrap(errors.CodeDatabaseError, err, "查询历史线下代充值创建人失败")
	}
	var shop model.Shop
	if err := s.db.WithContext(ctx).Where("id = ?", record.ShopID).First(&shop).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, nil, nil, errors.New(errors.CodeNotFound, "目标店铺不存在")
		}
		return nil, nil, nil, errors.Wrap(errors.CodeDatabaseError, err, "查询历史线下代充值目标店铺失败")
	}
	var wallet model.AgentWallet
	if err := s.db.WithContext(ctx).
		Where("id = ? AND shop_id = ? AND wallet_type = ? AND status = ?", record.AgentWalletID, record.ShopID, constants.AgentWalletTypeMain, constants.AgentWalletStatusNormal).
		First(&wallet).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, nil, nil, errors.New(errors.CodeWalletNotFound, "原充值主钱包不存在或不可用")
		}
		return nil, nil, nil, errors.Wrap(errors.CodeDatabaseError, err, "查询历史线下代充值主钱包失败")
	}
	return &account, &shop, &wallet, nil
}

func (s *OfflineCreationService) loadCreationFacts(
	ctx context.Context,
	command CreateOfflineCommand,
) (*model.Account, *model.Shop, *model.AgentWallet, error) {
	var account model.Account
	if err := s.db.WithContext(ctx).Where("id = ? AND status = ?", command.SubmitterAccountID, constants.StatusEnabled).First(&account).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, nil, nil, errors.New(errors.CodeForbidden, "提交人账号不可用")
		}
		return nil, nil, nil, errors.Wrap(errors.CodeDatabaseError, err, "查询线下代充值提交人失败")
	}
	var shop model.Shop
	if err := s.db.WithContext(ctx).Where("id = ?", command.ShopID).First(&shop).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, nil, nil, errors.New(errors.CodeNotFound, "目标店铺不存在")
		}
		return nil, nil, nil, errors.Wrap(errors.CodeDatabaseError, err, "查询目标店铺失败")
	}
	var wallet model.AgentWallet
	if err := s.db.WithContext(ctx).
		Where("shop_id = ? AND wallet_type = ? AND status = ?", command.ShopID, constants.AgentWalletTypeMain, constants.AgentWalletStatusNormal).
		First(&wallet).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, nil, nil, errors.New(errors.CodeWalletNotFound, "目标店铺主钱包不存在或不可用")
		}
		return nil, nil, nil, errors.Wrap(errors.CodeDatabaseError, err, "查询目标店铺主钱包失败")
	}
	return &account, &shop, &wallet, nil
}

func offlineApprovalSnapshots(command CreateOfflineCommand, submitterName, shopName, paymentMethodCode, paymentMethodName string) ([]byte, []byte, error) {
	submitterSnapshot, err := sonic.Marshal(map[string]any{
		"account_id": command.SubmitterAccountID, "account_name": submitterName,
		"user_type": command.SubmitterUserType,
	})
	if err != nil {
		return nil, nil, errors.Wrap(errors.CodeInternalError, err, "编码线下代充值提交人快照失败")
	}
	requestSnapshot, err := sonic.Marshal(map[string]any{
		constants.ApprovalFieldRechargeNo:               strings.TrimSpace(command.RechargeNo),
		constants.ApprovalFieldShopID:                   command.ShopID,
		constants.ApprovalFieldShopName:                 shopName,
		constants.ApprovalFieldAmount:                   fmt.Sprintf("%d.%02d", command.Amount/100, command.Amount%100),
		constants.ApprovalFieldAmountCent:               command.Amount,
		constants.ApprovalFieldPaymentVoucherKey:        command.PaymentVoucherKeys,
		constants.ApprovalFieldRemark:                   strings.TrimSpace(command.Remark),
		constants.ApprovalFieldSubmitterID:              command.SubmitterAccountID,
		constants.ApprovalFieldSubmitterName:            submitterName,
		constants.ApprovalFieldOfflinePaymentMethod:     paymentMethodName,
		constants.ApprovalFieldOfflinePaymentMethodCode: paymentMethodCode,
		constants.ApprovalFieldExternalTransactionNo:    strings.TrimSpace(command.ExternalTransactionNo),
		constants.ApprovalFieldOtherVoucherKey:          command.OtherVoucherKeys,
	})
	if err != nil {
		return nil, nil, errors.Wrap(errors.CodeInternalError, err, "编码线下代充值审批业务快照失败")
	}
	return submitterSnapshot, requestSnapshot, nil
}