package repository

import (
	"database/sql"
	"time"

	"github.com/wmms/wmms/internal/model"
	"github.com/wmms/wmms/pkg/database"
)

// orderQuerier 同时被 *sql.DB 与 *sql.Tx 满足，让单据头表加明细的读取逻辑能在
// 事务内外复用：事务内用 FOR UPDATE 锁定当前公司的原单据，事务外只做普通读取。
type orderQuerier interface {
	Query(query string, args ...interface{}) (*sql.Rows, error)
	QueryRow(query string, args ...interface{}) *sql.Row
}

type InboundRepo struct{}

func NewInboundRepo() *InboundRepo {
	return &InboundRepo{}
}

func (r *InboundRepo) Create(order *model.InboundOrder) error {
	return r.CreateTx(nil, order)
}

func (r *InboundRepo) CreateTx(tx *sql.Tx, order *model.InboundOrder) error {
	shouldCommit := false
	if tx == nil {
		var err error
		tx, err = database.DB.Begin()
		if err != nil {
			return err
		}
		shouldCommit = true
	}
	if shouldCommit {
		defer tx.Rollback()
	}

	// 三个库存维度由服务端解析后显式落库；表上这三列 NOT NULL 无默认值，缺一即报错，
	// 不会静默写进默认公司。
	query := `INSERT INTO inbound_orders (organization_id, warehouse_id, location_id, inbound_date, operator, handler, supplier, remark) VALUES (?, ?, ?, ?, ?, ?, ?, ?)`
	result, err := tx.Exec(query, order.OrganizationID, order.WarehouseID, order.LocationID, order.InboundDate, order.Operator, order.Handler, order.Supplier, order.Remark)
	if err != nil {
		return err
	}
	orderID, err := result.LastInsertId()
	if err != nil {
		return err
	}
	order.ID = orderID
	order.InboundNo = model.OrderNo("IN", orderID)
	if _, err = tx.Exec(`UPDATE inbound_orders SET inbound_no = ? WHERE id = ?`, order.InboundNo, orderID); err != nil {
		return err
	}

	for i := range order.Items {
		item := &order.Items[i]
		item.InboundOrderID = orderID
		query := `INSERT INTO inbound_items (inbound_order_id, material_id, quantity) VALUES (?, ?, ?)`
		result, err := tx.Exec(query, orderID, item.MaterialID, item.Quantity)
		if err != nil {
			return err
		}
		itemID, err := result.LastInsertId()
		if err != nil {
			return err
		}
		item.ID = itemID
	}

	if shouldCommit {
		return tx.Commit()
	}
	return nil
}

// loadInboundItems 读取单据明细，并 JOIN 头表与物料表把明细限制在同一组织内：
// 头表已按组织过滤，明细物料也必须属于同一公司，避免读到跨公司的物料行。
func loadInboundItems(q orderQuerier, orderID int64) ([]model.InboundItem, error) {
	itemsQuery := `SELECT ii.id, ii.inbound_order_id, ii.material_id, ii.quantity, m.material_code, m.name, m.status
		FROM inbound_items ii
		JOIN inbound_orders io ON io.id = ii.inbound_order_id
		JOIN materials m ON m.id = ii.material_id AND m.organization_id = io.organization_id
		WHERE ii.inbound_order_id = ?`
	rows, err := q.Query(itemsQuery, orderID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var items []model.InboundItem
	for rows.Next() {
		var item model.InboundItem
		if err := rows.Scan(&item.ID, &item.InboundOrderID, &item.MaterialID, &item.Quantity, &item.MaterialCode, &item.MaterialName, &item.MaterialStatus); err != nil {
			return nil, err
		}
		items = append(items, item)
	}
	return items, rows.Err()
}

// getByID 按公司读取单据头表加明细。lock=true 时用 FOR UPDATE 锁定当前公司的原单据，
// 供更新/删除事务在同一把锁下冲销原库存。别的公司的单据在这里命中 sql.ErrNoRows。
func (r *InboundRepo) getByID(q orderQuerier, organizationID, id int64, lock bool) (*model.InboundOrder, error) {
	order := &model.InboundOrder{}
	query := `SELECT id, COALESCE(inbound_no, CONCAT('IN-', LPAD(id, 8, '0'))), COALESCE(operator, ''), inbound_date, handler, supplier, COALESCE(remark, ''), organization_id, warehouse_id, location_id, created_at, updated_at FROM inbound_orders WHERE id = ? AND organization_id = ?`
	if lock {
		query += ` FOR UPDATE`
	}
	err := q.QueryRow(query, id, organizationID).Scan(&order.ID, &order.InboundNo, &order.Operator, &order.InboundDate, &order.Handler, &order.Supplier, &order.Remark, &order.OrganizationID, &order.WarehouseID, &order.LocationID, &order.CreatedAt, &order.UpdatedAt)
	if err != nil {
		return nil, err
	}

	order.Items, err = loadInboundItems(q, id)
	if err != nil {
		return nil, err
	}

	// 状态不落库：inbound_orders 没有 status 列，统一在这里给出。引入状态机时改为真实读写。
	order.Status = "completed"
	return order, nil
}

func (r *InboundRepo) GetByID(organizationID, id int64) (*model.InboundOrder, error) {
	return r.getByID(database.DB, organizationID, id, false)
}

// GetByIDForUpdateTx 在事务内锁定当前公司的原单据，别的公司的单据命中 ErrNoRows。
func (r *InboundRepo) GetByIDForUpdateTx(tx *sql.Tx, organizationID, id int64) (*model.InboundOrder, error) {
	return r.getByID(tx, organizationID, id, true)
}

func (r *InboundRepo) List(organizationID int64, search string, limit, offset int) ([]model.InboundOrder, int64, error) {
	// COUNT 和主查询是两条独立 SQL，组织条件与筛选条件必须成对出现，否则分页总数会和
	// 实际行数对不上。
	countQuery := `SELECT COUNT(*) FROM inbound_orders WHERE organization_id = ?`
	countArgs := []interface{}{organizationID}

	if search != "" {
		countQuery += ` AND (handler LIKE ? OR supplier LIKE ?)`
		searchPattern := "%" + search + "%"
		countArgs = append(countArgs, searchPattern, searchPattern)
	}

	var total int64
	err := database.DB.QueryRow(countQuery, countArgs...).Scan(&total)
	if err != nil {
		return nil, 0, err
	}

	query := `SELECT id, COALESCE(inbound_no, CONCAT('IN-', LPAD(id, 8, '0'))), COALESCE(operator, ''), inbound_date, handler, supplier, COALESCE(remark, ''), organization_id, warehouse_id, location_id, created_at, updated_at FROM inbound_orders WHERE organization_id = ?`
	args := []interface{}{organizationID}

	if search != "" {
		query += ` AND (handler LIKE ? OR supplier LIKE ?)`
		searchPattern := "%" + search + "%"
		args = append(args, searchPattern, searchPattern)
	}
	query += ` ORDER BY id DESC LIMIT ? OFFSET ?`
	args = append(args, limit, offset)

	rows, err := database.DB.Query(query, args...)
	if err != nil {
		return nil, 0, err
	}
	defer rows.Close()

	var orders []model.InboundOrder
	for rows.Next() {
		var order model.InboundOrder
		err := rows.Scan(&order.ID, &order.InboundNo, &order.Operator, &order.InboundDate, &order.Handler, &order.Supplier, &order.Remark, &order.OrganizationID, &order.WarehouseID, &order.LocationID, &order.CreatedAt, &order.UpdatedAt)
		if err != nil {
			return nil, 0, err
		}
		// 同上：状态在查询层给出，列表里一并补上。
		order.Status = "completed"
		orders = append(orders, order)
	}
	return orders, total, nil
}

// GetByMaterialID 返回某物料在本公司的入库历史。头表按组织过滤，明细 JOIN 的物料也
// 必须属于同一公司，公司 A 不能凭物料 ID 读到公司 B 的入库记录。
func (r *InboundRepo) GetByMaterialID(organizationID, materialID int64) ([]model.InboundRecord, error) {
	query := `SELECT ii.id, ii.inbound_order_id, io.handler, io.supplier, ii.quantity, ii.created_at
		FROM inbound_items ii
		JOIN inbound_orders io ON ii.inbound_order_id = io.id
		JOIN materials m ON ii.material_id = m.id AND m.organization_id = io.organization_id
		WHERE ii.material_id = ? AND io.organization_id = ?
		ORDER BY ii.id DESC`

	rows, err := database.DB.Query(query, materialID, organizationID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var records []model.InboundRecord
	for rows.Next() {
		var rec model.InboundRecord
		err := rows.Scan(&rec.ID, &rec.InboundID, &rec.Handler, &rec.Supplier, &rec.Quantity, &rec.CreatedAt)
		if err != nil {
			return nil, err
		}
		records = append(records, rec)
	}
	return records, nil
}

func (r *InboundRepo) GetInboundDate(organizationID, id int64) (time.Time, error) {
	var inboundDate time.Time
	query := `SELECT inbound_date FROM inbound_orders WHERE id = ? AND organization_id = ?`
	err := database.DB.QueryRow(query, id, organizationID).Scan(&inboundDate)
	return inboundDate, err
}

func (r *InboundRepo) Delete(organizationID, id int64) error {
	return r.DeleteTx(nil, organizationID, id)
}

func (r *InboundRepo) DeleteTx(tx *sql.Tx, organizationID, id int64) error {
	if tx == nil {
		var err error
		tx, err = database.DB.Begin()
		if err != nil {
			return err
		}
		defer tx.Rollback()
		_, err = tx.Exec(`DELETE FROM inbound_orders WHERE organization_id = ? AND id = ?`, organizationID, id)
		if err != nil {
			return err
		}
		return tx.Commit()
	}
	_, err := tx.Exec(`DELETE FROM inbound_orders WHERE organization_id = ? AND id = ?`, organizationID, id)
	return err
}

func (r *InboundRepo) Update(organizationID, id int64, req *model.UpdateInboundRequest) error {
	return r.UpdateTx(nil, organizationID, id, req)
}

func (r *InboundRepo) UpdateTx(tx *sql.Tx, organizationID, id int64, req *model.UpdateInboundRequest) error {
	shouldCommit := false
	if tx == nil {
		var err error
		tx, err = database.DB.Begin()
		if err != nil {
			return err
		}
		shouldCommit = true
	}
	if shouldCommit {
		defer tx.Rollback()
	}

	// 先确认目标单据属于本公司：跨公司的单据在这里直接返回 ErrNoRows，后面的明细
	// 删除/插入绝不会碰到别家公司的单据（明细表没有组织列，只能靠头表归属收口）。
	var existsID int64
	err := tx.QueryRow(`SELECT id FROM inbound_orders WHERE organization_id = ? AND id = ?`, organizationID, id).Scan(&existsID)
	if err == sql.ErrNoRows {
		return sql.ErrNoRows
	}
	if err != nil {
		return err
	}

	// Update order basic fields，写入带组织条件，跨公司的单据不会在这里被改动。
	query := `UPDATE inbound_orders SET handler = ?, supplier = ?, remark = ? WHERE organization_id = ? AND id = ?`
	_, err = tx.Exec(query, req.Handler, req.Supplier, req.Remark, organizationID, id)
	if err != nil {
		return err
	}

	// Delete old items
	_, err = tx.Exec(`DELETE FROM inbound_items WHERE inbound_order_id = ?`, id)
	if err != nil {
		return err
	}

	// Insert new items
	for i := range req.Items {
		item := &req.Items[i]
		query := `INSERT INTO inbound_items (inbound_order_id, material_id, quantity) VALUES (?, ?, ?)`
		_, err = tx.Exec(query, id, item.MaterialID, item.Quantity)
		if err != nil {
			return err
		}
	}

	if shouldCommit {
		return tx.Commit()
	}
	return nil
}