package repository

import (
	"database/sql"

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

type ApplicationRepository struct{}

func NewApplicationRepository() *ApplicationRepository {
	return &ApplicationRepository{}
}

func (r *ApplicationRepository) Create(app *model.MaterialApplication) error {
	tx, err := database.DB.Begin()
	if err != nil {
		return err
	}
	defer tx.Rollback()

	query := `INSERT INTO material_applications (user_id, purpose, status) VALUES (?, ?, ?)`
	result, err := tx.Exec(query, app.UserID, app.Purpose, app.Status)
	if err != nil {
		return err
	}
	id, err := result.LastInsertId()
	if err != nil {
		return err
	}
	app.ID = id

	// Insert application items
	for _, item := range app.Items {
		itemQuery := `INSERT INTO application_items (application_id, material_id, quantity) VALUES (?, ?, ?)`
		itemResult, err := tx.Exec(itemQuery, app.ID, item.MaterialID, item.Quantity)
		if err != nil {
			return err
		}
		itemID, _ := itemResult.LastInsertId()
		item.ID = itemID
	}

	return tx.Commit()
}

func (r *ApplicationRepository) GetByID(id int64) (*model.MaterialApplication, error) {
	query := `SELECT a.id, a.user_id, a.purpose, a.status, a.rejection_reason, a.approved_by, a.created_at, a.updated_at,
		u.username
		FROM material_applications a
		JOIN users u ON a.user_id = u.id
		WHERE a.id = ?`

	var app model.MaterialApplication
	err := database.DB.QueryRow(query, id).Scan(
		&app.ID, &app.UserID, &app.Purpose, &app.Status,
		&app.RejectionReason, &app.ApprovedBy, &app.CreatedAt, &app.UpdatedAt,
		&app.Username,
	)
	if err != nil {
		return nil, err
	}

	// Fetch items
	app.Items, err = r.GetApplicationItems(id)
	if err != nil {
		return nil, err
	}

	app.ApplicationNo = model.OrderNo("AP", app.ID)
	return &app, nil
}

func (r *ApplicationRepository) GetApplicationItems(applicationID int64) ([]model.ApplicationItem, error) {
	query := `SELECT ai.id, ai.application_id, ai.material_id, ai.quantity, m.material_code, m.name
		FROM application_items ai
		JOIN materials m ON ai.material_id = m.id
		WHERE ai.application_id = ?`

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

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

func (r *ApplicationRepository) ListAll(status string, userID int64, limit, offset int) ([]model.MaterialApplication, int, error) {
	// Count query
	countQuery := `SELECT COUNT(*) FROM material_applications a WHERE 1=1`
	var countArgs []interface{}
	if status != "" {
		countQuery += " AND a.status = ?"
		countArgs = append(countArgs, status)
	}
	if userID > 0 {
		countQuery += " AND a.user_id = ?"
		countArgs = append(countArgs, userID)
	}

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

	// Data query
	query := `SELECT a.id, a.user_id, a.purpose, a.status, a.rejection_reason, a.approved_by, a.created_at, a.updated_at,
		u.username
		FROM material_applications a
		JOIN users u ON a.user_id = u.id
		WHERE 1=1`

	var args []interface{}
	if status != "" {
		query += " AND a.status = ?"
		args = append(args, status)
	}
	if userID > 0 {
		query += " AND a.user_id = ?"
		args = append(args, userID)
	}
	query += " ORDER BY a.created_at 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 apps []model.MaterialApplication
	for rows.Next() {
		var app model.MaterialApplication
		err := rows.Scan(
			&app.ID, &app.UserID, &app.Purpose, &app.Status,
			&app.RejectionReason, &app.ApprovedBy, &app.CreatedAt, &app.UpdatedAt,
			&app.Username,
		)
		if err != nil {
			return nil, 0, err
		}
		// Fetch items for each application
		app.Items, err = r.GetApplicationItems(app.ID)
		if err != nil {
			return nil, 0, err
		}
		app.ApplicationNo = model.OrderNo("AP", app.ID)
		apps = append(apps, app)
	}
	return apps, total, nil
}

func (r *ApplicationRepository) ListByUserID(userID int64, status string, limit, offset int) ([]model.MaterialApplication, int, error) {
	return r.ListAll(status, userID, limit, offset)
}

func (r *ApplicationRepository) ListAllApplications(status string, limit, offset int) ([]model.MaterialApplication, int, error) {
	return r.ListAll(status, 0, limit, offset)
}

func (r *ApplicationRepository) UpdateStatus(id int64, status string) error {
	query := `UPDATE material_applications SET status = ?, updated_at = NOW() WHERE id = ?`
	_, err := database.DB.Exec(query, status, id)
	return err
}

func (r *ApplicationRepository) Approve(id int64, approverID int64) error {
	query := `UPDATE material_applications SET status = ?, approved_by = ?, updated_at = NOW() WHERE id = ?`
	_, err := database.DB.Exec(query, model.ApplicationStatusApproved, approverID, id)
	return err
}

func (r *ApplicationRepository) Reject(id int64, reason string) error {
	query := `UPDATE material_applications SET status = ?, rejection_reason = ?, updated_at = NOW() WHERE id = ?`
	_, err := database.DB.Exec(query, model.ApplicationStatusRejected, reason, id)
	return err
}

func (r *ApplicationRepository) Cancel(id int64) error {
	return r.UpdateStatus(id, model.ApplicationStatusCancelled)
}

func (r *ApplicationRepository) GetByIDWithDetails(id int64) (*model.MaterialApplication, error) {
	return r.GetByID(id)
}

// outbound_orders 没有 status 列：出库单一经创建即为完成态，
// 这里与手工出库路径（OutboundRepo.CreateTx）写入同样的列。
func (r *ApplicationRepository) CreateOutboundOrder(order *model.OutboundOrder) error {
	query := `INSERT INTO outbound_orders (outbound_date, operator, handler, receiver) VALUES (NOW(), ?, ?, ?)`
	result, err := database.DB.Exec(query, order.Operator, order.Handler, order.Receiver)
	if err != nil {
		return err
	}
	id, err := result.LastInsertId()
	if err != nil {
		return err
	}
	order.ID = id
	order.OutboundNo = model.OrderNo("OUT", id)
	if _, err := database.DB.Exec(`UPDATE outbound_orders SET outbound_no = ? WHERE id = ?`, order.OutboundNo, id); err != nil {
		return err
	}
	return nil
}

// outbound_orders 与 inbound_orders 一样没有 status 列，单据状态由查询层统一写死。
// 这里写入的列必须和手工出库（OutboundRepo.CreateTx）一致，多写一列会让 INSERT 直接失败。
func (r *ApplicationRepository) CreateOutboundOrderTx(tx *sql.Tx, order *model.OutboundOrder) error {
	query := `INSERT INTO outbound_orders (outbound_date, operator, handler, receiver) VALUES (NOW(), ?, ?, ?)`
	result, err := tx.Exec(query, order.Operator, order.Handler, order.Receiver)
	if err != nil {
		return err
	}
	id, err := result.LastInsertId()
	if err != nil {
		return err
	}
	order.ID = id
	order.OutboundNo = model.OrderNo("OUT", id)
	if _, err := tx.Exec(`UPDATE outbound_orders SET outbound_no = ? WHERE id = ?`, order.OutboundNo, id); err != nil {
		return err
	}
	return nil
}

func (r *ApplicationRepository) CreateOutboundItem(item *model.OutboundItem) error {
	query := `INSERT INTO outbound_items (outbound_order_id, material_id, quantity) VALUES (?, ?, ?)`
	result, err := database.DB.Exec(query, item.OutboundOrderID, item.MaterialID, item.Quantity)
	if err != nil {
		return err
	}
	id, err := result.LastInsertId()
	if err != nil {
		return err
	}
	item.ID = id
	return nil
}

func (r *ApplicationRepository) CreateOutboundItemTx(tx *sql.Tx, item *model.OutboundItem) error {
	query := `INSERT INTO outbound_items (outbound_order_id, material_id, quantity) VALUES (?, ?, ?)`
	result, err := tx.Exec(query, item.OutboundOrderID, item.MaterialID, item.Quantity)
	if err != nil {
		return err
	}
	id, err := result.LastInsertId()
	if err != nil {
		return err
	}
	item.ID = id
	return nil
}

func (r *ApplicationRepository) CreateStockLog(log *model.StockLog) error {
	query := `INSERT INTO stock_logs (material_id, type, quantity, related_order_type, related_order_id) VALUES (?, ?, ?, ?, ?)`
	result, err := database.DB.Exec(query, log.MaterialID, log.Type, log.Quantity, log.RelatedOrderType, log.RelatedOrderID)
	if err != nil {
		return err
	}
	_, err = result.LastInsertId()
	return err
}

func (r *ApplicationRepository) CreateStockLogTx(tx *sql.Tx, log *model.StockLog) error {
	query := `INSERT INTO stock_logs (material_id, type, quantity, related_order_type, related_order_id) VALUES (?, ?, ?, ?, ?)`
	result, err := tx.Exec(query, log.MaterialID, log.Type, log.Quantity, log.RelatedOrderType, log.RelatedOrderID)
	if err != nil {
		return err
	}
	_, err = result.LastInsertId()
	return err
}

func (r *ApplicationRepository) ApproveTx(tx *sql.Tx, id int64, approverID int64) error {
	query := `UPDATE material_applications SET status = ?, approved_by = ?, updated_at = NOW() WHERE id = ?`
	_, err := tx.Exec(query, model.ApplicationStatusApproved, approverID, id)
	return err
}

func (r *ApplicationRepository) GetApproverName(userID int64) (string, error) {
	query := `SELECT username FROM users WHERE id = ?`
	var username string
	err := database.DB.QueryRow(query, userID).Scan(&username)
	return username, err
}

func (r *ApplicationRepository) InitApplicationTable() error {
	query := `
	CREATE TABLE IF NOT EXISTS material_applications (
		id BIGINT AUTO_INCREMENT PRIMARY KEY,
		user_id BIGINT NOT NULL,
		purpose VARCHAR(500) DEFAULT '',
		status ENUM('pending','approved','rejected','cancelled') NOT NULL DEFAULT 'pending',
		rejection_reason VARCHAR(500) DEFAULT '',
		approved_by BIGINT DEFAULT 0,
		created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
		updated_at DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
	)`
	_, err := database.DB.Exec(query)
	if err != nil {
		return err
	}

	// Create application_items table
	itemsQuery := `
	CREATE TABLE IF NOT EXISTS application_items (
		id BIGINT AUTO_INCREMENT PRIMARY KEY,
		application_id BIGINT NOT NULL,
		material_id BIGINT NOT NULL,
		quantity INT NOT NULL,
		FOREIGN KEY (application_id) REFERENCES material_applications(id) ON DELETE CASCADE,
		FOREIGN KEY (material_id) REFERENCES materials(id)
	)`
	_, err = database.DB.Exec(itemsQuery)
	return err
}