package service

import (
	"context"
	"strings"

	entity "gitlab.com/mbugroup/lti-api.git/internal/entities"
	"gorm.io/gorm"
)

type FifoStockV2RouteRule struct {
	FlagGroupCode       string `gorm:"column:flag_group_code"`
	Lane                string `gorm:"column:lane"`
	FunctionCode        string `gorm:"column:function_code"`
	SourceTable         string `gorm:"column:source_table"`
	LegacyTypeKey       string `gorm:"column:legacy_type_key"`
	AllowPendingDefault bool   `gorm:"column:allow_pending_default"`
}

func ResolveFifoStockV2RouteByProductIDAndLane(
	ctx context.Context,
	db *gorm.DB,
	productID uint,
	functionCode string,
	lane FifoStockV2Lane,
) (*FifoStockV2RouteRule, error) {
	rows, err := resolveFifoStockV2RoutesByProductID(ctx, db, productID, functionCode, lane)
	if err != nil {
		return nil, err
	}
	if len(rows) == 0 {
		return nil, nil
	}
	selected := rows[0]
	return &selected, nil
}

func ResolveFifoStockV2RouteByProductWarehouseIDAndLane(
	ctx context.Context,
	db *gorm.DB,
	productWarehouseID uint,
	functionCode string,
	lane FifoStockV2Lane,
) (*FifoStockV2RouteRule, error) {
	rows, err := resolveFifoStockV2RoutesByProductWarehouseID(ctx, db, productWarehouseID, functionCode, lane)
	if err != nil {
		return nil, err
	}
	if len(rows) == 0 {
		return nil, nil
	}
	selected := rows[0]
	return &selected, nil
}

func resolveFifoStockV2RoutesByProductID(
	ctx context.Context,
	db *gorm.DB,
	productID uint,
	functionCode string,
	lane FifoStockV2Lane,
) ([]FifoStockV2RouteRule, error) {
	normalizedCode := strings.ToUpper(strings.TrimSpace(functionCode))
	if db == nil || productID == 0 || normalizedCode == "" {
		return []FifoStockV2RouteRule{}, nil
	}

	query := db.WithContext(ctx).
		Table("fifo_stock_v2_route_rules rr").
		Select("rr.flag_group_code, rr.lane, rr.function_code, rr.source_table, rr.legacy_type_key, rr.allow_pending_default").
		Joins("JOIN fifo_stock_v2_flag_groups fg ON fg.code = rr.flag_group_code AND fg.is_active = TRUE").
		Where("rr.is_active = TRUE").
		Where("rr.function_code = ?", normalizedCode).
		Where(`
			EXISTS (
				SELECT 1
				FROM flags f
				JOIN fifo_stock_v2_flag_members fm ON fm.flag_name = f.name AND fm.is_active = TRUE
				WHERE f.flagable_type = ?
				  AND f.flagable_id = ?
				  AND fm.flag_group_code = rr.flag_group_code
			)
		`, entity.FlagableTypeProduct, productID)

	if lane == FifoStockV2LaneStockable || lane == FifoStockV2LaneUsable {
		query = query.Where("rr.lane = ?", string(lane))
	}

	var rows []FifoStockV2RouteRule
	err := query.
		Order("CASE WHEN rr.source_table = 'adjustment_stocks' THEN 0 ELSE 1 END ASC").
		Order("rr.id ASC").
		Find(&rows).Error
	if err != nil {
		return nil, err
	}

	return rows, nil
}

func resolveFifoStockV2RoutesByProductWarehouseID(
	ctx context.Context,
	db *gorm.DB,
	productWarehouseID uint,
	functionCode string,
	lane FifoStockV2Lane,
) ([]FifoStockV2RouteRule, error) {
	normalizedCode := strings.ToUpper(strings.TrimSpace(functionCode))
	if db == nil || productWarehouseID == 0 || normalizedCode == "" {
		return []FifoStockV2RouteRule{}, nil
	}

	query := db.WithContext(ctx).
		Table("fifo_stock_v2_route_rules rr").
		Select("rr.flag_group_code, rr.lane, rr.function_code, rr.source_table, rr.legacy_type_key, rr.allow_pending_default").
		Joins("JOIN fifo_stock_v2_flag_groups fg ON fg.code = rr.flag_group_code AND fg.is_active = TRUE").
		Where("rr.is_active = TRUE").
		Where("rr.function_code = ?", normalizedCode).
		Where(`
			EXISTS (
				SELECT 1
				FROM product_warehouses pw
				JOIN flags f ON f.flagable_type = ? AND f.flagable_id = pw.product_id
				JOIN fifo_stock_v2_flag_members fm ON fm.flag_name = f.name AND fm.is_active = TRUE
				WHERE pw.id = ?
				  AND fm.flag_group_code = rr.flag_group_code
			)
		`, entity.FlagableTypeProduct, productWarehouseID)

	if lane == FifoStockV2LaneStockable || lane == FifoStockV2LaneUsable {
		query = query.Where("rr.lane = ?", string(lane))
	}

	var rows []FifoStockV2RouteRule
	err := query.
		Order("CASE WHEN rr.source_table = 'adjustment_stocks' THEN 0 ELSE 1 END ASC").
		Order("rr.id ASC").
		Find(&rows).Error
	if err != nil {
		return nil, err
	}

	return rows, nil
}