import { getRelativePosition } from './custom.util.js'

const EDITOR_CLASS = 'jsmind-editor' // jsmind class name
const SUGGESTION_BOX_CLASS = 'jsmind-suggestions'
const SUGGESTION_ITEM_CLASS = 'suggestion-item'

/**
 * jsMind 搜尋管理
 * jsMind Search Manager
 */
export class JsmindSearch {
    /**
     * 建構搜尋
     * Constructor for search
     * @param {Object} jm - jsMind 實例 (jsMind instance)
     * @param {Function} searchAPI - 遠程搜尋 API 函式 (Remote search API function)
     * @param {string} tableUID
     */
    constructor(jm, searchAPI, tableUID) {
        this.jm = jm
        this.searchAPI = searchAPI
        this.container = document.getElementById(jm.options.container)
        this.suggestionBox = null
        this.tableUID = tableUID
        this.init()
    }

    /**
     * 初始化搜尋事件
     * Initialize search events
     */
    init() {
        // 確保不會重複綁定 dblclick 事件
        // Ensure double-click event is not bound multiple times
        this.container.removeEventListener('dblclick', this.onDoubleClick)
        this.container.addEventListener('dblclick', this.onDoubleClick.bind(this))
    }

    /**
     * 處理雙擊事件以觸發搜尋
     * Handle double-click event to trigger search
     * @param {Event} e - 事件對象 (Event object)
     */
    onDoubleClick(e) {
        // 非可編輯狀態不執行
        // Ignore if not editable
        if (!this.jm.options.editable) return

        const node = this.jm.get_selected_node()
        if (!node) return

        // 避免影響原生編輯功能，稍後執行
        // Prevent interfering with native edit mode
        setTimeout(() => this.handleSearch(node), 100)
    }

    /**
     * 開始處理搜尋
     * Start handling search
     * @param {Object} node - 當前選中節點 (Selected node)
     */
    handleSearch(node) {
        const inputField = document.querySelector(`.${EDITOR_CLASS}`)
        if (!inputField) return

        // 確保不會重複綁定 input 事件
        // Ensure input event is not bound multiple times
        inputField.removeEventListener('input', this.onInput)
        inputField.addEventListener('input', this.onInput.bind(this, node))
    }

    /**
     * 處理使用者輸入
     * Handle user input
     * @param {Object} node - 當前選中節點 (Selected node)
     * @param {Event} e - 輸入事件 (Input event)
     */
    async onInput(node, e) {
        const query = e.target.value.trim()
        if (!query) return
        await new Promise(resolve => setTimeout(resolve, 500));
        try {
            const results = await this.searchAPI(query, this.tableUID)
            this.showSuggestion(node, e.target, results)
        } catch (error) {
            // Search API error handling
            console.error('搜尋 API 錯誤:', error)
        }
    }

    /**
     * 顯示搜尋建議框
     * Show search suggestion box
     * @param {Object} node - 當前選中節點 (Selected node)
     * @param {HTMLElement} inputElement - 輸入框 (Input field)
     * @param {Array} results - 搜尋結果 (Search results)
     */
    showSuggestion(node, inputElement, results) {
        const container = this.container
        const nodeElement = inputElement.parentNode
        if (!nodeElement) return

        const { left, top, height } = getRelativePosition(nodeElement, container)
        this.suggestionBox = this.suggestionBox || this.createSuggestionBox()

        // 更新建議框內容
        // Update suggestion box content
        this.suggestionBox.innerHTML = results
            .map(
                (item) =>
                    `<div class="${SUGGESTION_ITEM_CLASS}" data-link="${item.link}" data-text="${item.text}">${item.text}</div>`
            )
            .join('')

        this.suggestionBox.style.left = `${left}px`
        this.suggestionBox.style.top = `${top + height}px`
        this.suggestionBox.style.display = 'block'

        // 綁定建議點擊事件
        // Bind suggestion click events
        document.querySelectorAll(`.${SUGGESTION_ITEM_CLASS}`).forEach((item) => {
            item.removeEventListener('mousedown', this.onSuggestionClick)
            item.addEventListener('mousedown', this.onSuggestionClick.bind(this, node))
        })
    }

    /**
     * 建立搜尋建議框
     * Create search suggestion box
     * @returns {HTMLElement} - 建議框 DOM (Suggestion box DOM)
     */
    createSuggestionBox() {
        let suggestionBox = document.getElementById(SUGGESTION_BOX_CLASS)
        if (!suggestionBox) {
            suggestionBox = document.createElement('div')
            suggestionBox.classList.add(SUGGESTION_BOX_CLASS)
            this.container.appendChild(suggestionBox)
        }
        return suggestionBox
    }

    /**
     * 處理點擊建議
     * Handle suggestion click
     * @param {Object} node - 當前選中節點 (Selected node)
     * @param {Event} e - 點擊事件 (Click event)
     */
    onSuggestionClick(node, e) {
        e.preventDefault()

        const text = e.target.getAttribute('data-text')
        const link = e.target.getAttribute('data-link')

        node.data.text = text
        node.data.link = link

        this.jm.end_edit()
        this.jm.update_node(node.id, text)

        // 選擇後隱藏建議框
        // Hide suggestions after selection
        this.suggestionBox.style.display = 'none'
    }
}