package delivery

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"math"
	"time"

	"git.apinb.com/bsm-sdk/core/errcode"
	"git.apinb.com/bsm-sdk/core/infra"
	"git.apinb.com/heqiapp/platforms/backend/api/internal/logic/common"
	platformgasorder "git.apinb.com/heqiapp/platforms/backend/api/internal/logic/platform/gasorder"
	"git.apinb.com/heqiapp/platforms/backend/api/internal/models"
	"github.com/gin-gonic/gin"
	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

func rewriteJSON(ctx *gin.Context, mutate func(map[string]any) bool) bool {
	body, err := io.ReadAll(ctx.Request.Body)
	if err != nil {
		infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		return false
	}
	var values map[string]any
	if json.Unmarshal(body, &values) != nil || !mutate(values) {
		if !ctx.IsAborted() {
			infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		}
		return false
	}
	body, _ = json.Marshal(values)
	ctx.Request.Body = io.NopCloser(bytes.NewReader(body))
	return true
}

func scopedContract(ctx *gin.Context, identity string, pointID uint64) (models.GasorderContract, bool) {
	var contract models.GasorderContract
	if err := common.ActiveRecords(db()).Where("identity = ? AND delivery_basic_id = ?", identity, pointID).First(&contract).Error; err != nil {
		common.RespondRecordError(ctx, err)
		return contract, false
	}
	return contract, true
}

func ListContract(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if ok {
		listScoped(ctx, &models.GasorderContract{}, common.ActiveRecords(db().Model(&models.GasorderContract{})).
			Where("gas_basic_id = ? AND delivery_basic_id = ?", point.GasBasicID, point.ID), "gasorder_contract.created_at desc")
	}
}

func GetContract(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if ok {
		if _, valid := scopedContract(ctx, ctx.Param("identity"), point.ID); valid {
			platformgasorder.GetGasorderContract(ctx)
		}
	}
}

func CreateContract(ctx *gin.Context) {
	point, station, ok := currentScope(ctx)
	if !ok {
		return
	}
	if !rewriteJSON(ctx, func(values map[string]any) bool {
		userIdentity, _ := values["user_account_identity"].(string)
		if _, _, valid := scopedUser(ctx, userIdentity, point.ID); !valid {
			return false
		}
		values["gas_basic_identity"] = station.Identity
		values["delivery_basic_identity"] = point.Identity
		return true
	}) {
		return
	}
	platformgasorder.CreateGasorderContract(ctx)
}

func withContract(ctx *gin.Context, handler gin.HandlerFunc) {
	point, _, ok := currentScope(ctx)
	if ok {
		if _, valid := scopedContract(ctx, ctx.Param("identity"), point.ID); valid {
			handler(ctx)
		}
	}
}

func UpdateContract(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if !ok {
		return
	}
	if _, valid := scopedContract(ctx, ctx.Param("identity"), point.ID); !valid {
		return
	}
	if !rewriteJSON(ctx, func(values map[string]any) bool {
		values["delivery_basic_identity"] = point.Identity
		return true
	}) {
		return
	}
	platformgasorder.UpdateGasorderContract(ctx)
}
func ActivateContract(ctx *gin.Context) { withContract(ctx, platformgasorder.ActivateGasorderContract) }
func RenewContract(ctx *gin.Context)    { withContract(ctx, platformgasorder.RenewGasorderContract) }
func TerminateContract(ctx *gin.Context) {
	withContract(ctx, platformgasorder.TerminateGasorderContract)
}

func ListContractProduct(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if !ok {
		return
	}
	query := common.ActiveRecords(db().Model(&models.GasorderContractProduct{})).
		Joins("JOIN gasorder_contract ON gasorder_contract.id = gasorder_contract_product.gasorder_contract_id").
		Where("gasorder_contract.delivery_basic_id = ?", point.ID)
	listScoped(ctx, &models.GasorderContractProduct{}, query, "gasorder_contract_product.created_at desc")
}

func GetContractProduct(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if !ok {
		return
	}
	var item models.GasorderContractProduct
	query := common.ActiveRecords(db().Model(&models.GasorderContractProduct{})).
		Select("gasorder_contract_product.*").
		Joins("JOIN gasorder_contract ON gasorder_contract.id = gasorder_contract_product.gasorder_contract_id").
		Where("gasorder_contract_product.identity = ? AND gasorder_contract.delivery_basic_id = ?", ctx.Param("identity"), point.ID)
	respondRecord(ctx, query, &item)
}

func BindContractProduct(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if !ok {
		return
	}
	if !rewriteJSON(ctx, func(values map[string]any) bool {
		identity, _ := values["gasorder_contract_identity"].(string)
		_, valid := scopedContract(ctx, identity, point.ID)
		return valid
	}) {
		return
	}
	platformgasorder.BindGasorderContractProduct(ctx)
}

func UnbindContractProduct(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if !ok {
		return
	}
	var count int64
	err := db().Model(&models.GasorderContractProduct{}).
		Joins("JOIN gasorder_contract ON gasorder_contract.id = gasorder_contract_product.gasorder_contract_id").
		Where("gasorder_contract_product.identity = ? AND gasorder_contract.delivery_basic_id = ?", ctx.Param("identity"), point.ID).
		Count(&count).Error
	if err != nil || count != 1 {
		infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		return
	}
	platformgasorder.UnbindGasorderContractProduct(ctx)
}

func ListContractRevision(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if !ok {
		return
	}
	query := common.ActiveRecords(db().Model(&models.GasorderContractRevision{})).
		Joins("JOIN gasorder_contract ON gasorder_contract.id = gasorder_contract_revision.gasorder_contract_id").
		Where("gasorder_contract.delivery_basic_id = ?", point.ID)
	listScoped(ctx, &models.GasorderContractRevision{}, query, "gasorder_contract_revision.created_at desc")
}

func GetContractRevision(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if !ok {
		return
	}
	var item models.GasorderContractRevision
	query := common.ActiveRecords(db().Model(&models.GasorderContractRevision{})).
		Select("gasorder_contract_revision.*").
		Joins("JOIN gasorder_contract ON gasorder_contract.id = gasorder_contract_revision.gasorder_contract_id").
		Where("gasorder_contract_revision.identity = ? AND gasorder_contract.delivery_basic_id = ?", ctx.Param("identity"), point.ID)
	respondRecord(ctx, query, &item)
}

func ListProductCandidate(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if !ok {
		return
	}
	query := common.ActiveRecords(db().Model(&models.ProductInfo{})).
		Joins("JOIN user_service_relation ON user_service_relation.user_account_id = product_info.user_account_id AND user_service_relation.status <> ?",
			common.StatusArchived).Where("user_service_relation.delivery_basic_id = ?", point.ID)
	listScoped(ctx, &models.ProductInfo{}, query, "product_info.created_at desc")
}

func GetProductCandidate(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if !ok {
		return
	}
	var item models.ProductInfo
	query := common.ActiveRecords(db().Model(&models.ProductInfo{})).
		Select("product_info.*").
		Joins("JOIN user_service_relation ON user_service_relation.user_account_id = product_info.user_account_id AND user_service_relation.status <> ?",
			common.StatusArchived).
		Where("product_info.identity = ? AND user_service_relation.delivery_basic_id = ?", ctx.Param("identity"), point.ID)
	respondRecord(ctx, query, &item)
}

func scopedOrder(ctx *gin.Context, identity string, pointID uint64) (models.GasorderBasic, bool) {
	var order models.GasorderBasic
	if err := common.ActiveRecords(db()).Where("identity = ? AND delivery_basic_id = ?", identity, pointID).First(&order).Error; err != nil {
		common.RespondRecordError(ctx, err)
		return order, false
	}
	return order, true
}

func ListOrder(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if ok {
		listScoped(ctx, &models.GasorderBasic{}, common.ActiveRecords(db().Model(&models.GasorderBasic{})).
			Where("delivery_basic_id = ?", point.ID), "gasorder_basic.created_at desc")
	}
}

func GetOrder(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if ok {
		if _, valid := scopedOrder(ctx, ctx.Param("identity"), point.ID); valid {
			platformgasorder.GetGasorderBasic(ctx)
		}
	}
}

func CreateOrder(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if !ok {
		return
	}
	if !rewriteJSON(ctx, func(values map[string]any) bool {
		identity, _ := values["gasorder_contract_identity"].(string)
		if _, valid := scopedContract(ctx, identity, point.ID); !valid {
			return false
		}
		values["creator_type"] = "delivery"
		values["creator_identity"] = point.Identity
		return true
	}) {
		return
	}
	platformgasorder.CreateGasorderBasic(ctx)
}

func AssignOrder(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if !ok {
		return
	}
	if _, valid := scopedOrder(ctx, ctx.Param("identity"), point.ID); !valid {
		return
	}
	if !rewriteJSON(ctx, func(values map[string]any) bool {
		staffIdentity, _ := values["staff_account_identity"].(string)
		staff, valid := scopedStaff(ctx, staffIdentity, point)
		if !valid || staff.WorkStatus != "on_duty" || staff.Status != common.StatusEnable {
			return false
		}
		var credentialCount int64
		err := common.ActiveRecords(db().Model(&models.StaffCredential{})).
			Where("staff_account_id = ? AND (expired_at IS NULL OR expired_at > ?)", staff.ID, time.Now()).
			Count(&credentialCount).Error
		if err != nil || credentialCount == 0 {
			return false
		}
		values["delivery_basic_identity"] = point.Identity
		return true
	}) {
		return
	}
	platformgasorder.AssignGasorderBasic(ctx)
}

func withOrder(ctx *gin.Context, handler gin.HandlerFunc) {
	point, _, ok := currentScope(ctx)
	if ok {
		if _, valid := scopedOrder(ctx, ctx.Param("identity"), point.ID); valid {
			handler(ctx)
		}
	}
}

func OrderException(ctx *gin.Context) { withOrder(ctx, platformgasorder.GasorderException) }
func OrderRecover(ctx *gin.Context)   { withOrder(ctx, platformgasorder.GasorderRecover) }
func OrderCancel(ctx *gin.Context)    { withOrder(ctx, platformgasorder.GasorderCancel) }

func ReclaimOrder(ctx *gin.Context) {
	account, point, _, ok := CurrentDeliveryAccount(ctx)
	if !ok {
		return
	}
	var request struct {
		Reason string `json:"reason" binding:"required,max=1000"`
	}
	if err := ctx.ShouldBindJSON(&request); err != nil {
		infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		return
	}
	err := db().Transaction(func(tx *gorm.DB) error {
		var order models.GasorderBasic
		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).
			Where("identity = ? AND delivery_basic_id = ?", ctx.Param("identity"), point.ID).First(&order).Error; err != nil {
			return err
		}
		if order.OrderStatus != common.StatusAssigned {
			return errors.New("only assigned order can be reclaimed")
		}
		if err := tx.Model(&order).Updates(map[string]any{
			"staff_account_id": 0, "order_status": common.StatusCreated,
		}).Error; err != nil {
			return err
		}
		return tx.Create(&models.GasorderStatus{
			Entity: common.NewEntity(common.StatusEnable), GasorderBasicID: order.ID,
			FromStatus: common.StatusAssigned, ToStatus: common.StatusCreated,
			OperatorIdentity: account.Identity, OperatorName: account.DisplayName,
			OccurredAt: time.Now(), Reason: request.Reason,
		}).Error
	})
	if err != nil {
		infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		return
	}
	infra.Response.Success(ctx, gin.H{"updated": true, "order_status": common.StatusCreated})
}

func AdjustOrderAmount(ctx *gin.Context) {
	point, _, ok := currentScope(ctx)
	if !ok {
		return
	}
	var request struct {
		DeliveryFee    int64  `json:"delivery_fee"`
		DiscountAmount int64  `json:"discount_amount"`
		Reason         string `json:"reason" binding:"required,max=1000"`
	}
	if err := ctx.ShouldBindJSON(&request); err != nil || request.DeliveryFee < 0 || request.DiscountAmount < 0 {
		infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		return
	}
	account, _, _, _ := CurrentDeliveryAccount(ctx)
	err := db().Transaction(func(tx *gorm.DB) error {
		var order models.GasorderBasic
		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).
			Where("identity = ? AND delivery_basic_id = ?", ctx.Param("identity"), point.ID).First(&order).Error; err != nil {
			return err
		}
		if order.OrderStatus != common.StatusCreated && order.OrderStatus != common.StatusAssigned {
			return errors.New("order amount cannot be adjusted")
		}
		var paymentCount int64
		if err := tx.Model(&models.GasorderPayment{}).
			Joins("JOIN payment_order ON payment_order.id = gasorder_payment.payment_order_id").
			Where("gasorder_payment.gasorder_basic_id = ? AND payment_order.payment_status = ?", order.ID, 23).
			Count(&paymentCount).Error; err != nil || paymentCount > 0 {
			return errors.New("paid order cannot be adjusted")
		}
		if order.ProductAmount > math.MaxInt64-request.DeliveryFee {
			return errors.New("payable amount overflow")
		}
		payable := order.ProductAmount + request.DeliveryFee - request.DiscountAmount
		if payable <= 0 {
			return errors.New("payable amount must be positive")
		}
		if err := tx.Model(&order).Updates(map[string]any{
			"delivery_fee": request.DeliveryFee, "discount_amount": request.DiscountAmount, "payable_amount": payable,
		}).Error; err != nil {
			return err
		}
		record := models.GasorderStatus{
			Entity: common.NewEntity(common.StatusEnable), GasorderBasicID: order.ID,
			FromStatus: order.OrderStatus, ToStatus: order.OrderStatus,
			OperatorIdentity: account.Identity, OperatorName: account.DisplayName, OccurredAt: time.Now(),
			Reason: fmt.Sprintf("%s；配送费 %d→%d，优惠金额 %d→%d，应付金额 %d→%d",
				request.Reason, order.DeliveryFee, request.DeliveryFee, order.DiscountAmount, request.DiscountAmount,
				order.PayableAmount, payable),
		}
		return tx.Create(&record).Error
	})
	if err != nil {
		infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		return
	}
	infra.Response.Success(ctx, gin.H{"updated": true})
}