const VCONSOLE_QUERY_KEY = 'vconsole'
const VCONSOLE_STORAGE_KEY = '__ENABLE_VCONSOLE__'
const VCONSOLE_SCRIPT_URL = 'https://cdn.jsdelivr.net/npm/vconsole@3.15.1/dist/vconsole.min.js'

let vConsoleBootstrapped = false

/**
 * 仅在 H5 环境按需启用 vConsole，方便 iOS 真机排查分享页问题。
 * 开启方式：
 * 1. 链接追加 ?vconsole=1 或 &vconsole=1
 * 2. 开启后会写入 localStorage，后续刷新页面仍保持开启
 * 3. 链接追加 ?vconsole=0 可关闭
 */
export function initH5DebugPanel() {
    if (typeof window === 'undefined' || vConsoleBootstrapped) {
        return
    }
    const debugFlag = resolveDebugFlag()
    if (!debugFlag) {
        return
    }
    vConsoleBootstrapped = true
    bindGlobalDebugEvents()
    loadVConsoleScript()
}

function resolveDebugFlag() {
    const queryValue = getQueryParamValue(VCONSOLE_QUERY_KEY)
    if (queryValue === '1') {
        safeSetStorage(VCONSOLE_STORAGE_KEY, '1')
        return true
    }
    if (queryValue === '0') {
        safeRemoveStorage(VCONSOLE_STORAGE_KEY)
        return false
    }
    return safeGetStorage(VCONSOLE_STORAGE_KEY) === '1'
}

function bindGlobalDebugEvents() {
    window.addEventListener('error', (event) => {
        const error = event.error
        console.error('[h5-debug] window error:', {
            message: event.message,
            source: event.filename,
            line: event.lineno,
            column: event.colno,
            stack: error && error.stack ? error.stack : '',
        })
    })
    window.addEventListener('unhandledrejection', (event) => {
        console.error('[h5-debug] unhandled rejection:', event.reason)
    })
}

function loadVConsoleScript() {
    if (window.VConsole) {
        createVConsoleInstance()
        return
    }
    const existingScript = document.querySelector(`script[data-debug-tool="${VCONSOLE_QUERY_KEY}"]`)
    if (existingScript) {
        existingScript.addEventListener('load', createVConsoleInstance, { once: true })
        return
    }
    const script = document.createElement('script')
    script.src = VCONSOLE_SCRIPT_URL
    script.async = true
    script.setAttribute('data-debug-tool', VCONSOLE_QUERY_KEY)
    script.onload = createVConsoleInstance
    script.onerror = () => {
        console.error('[h5-debug] vConsole 加载失败:', VCONSOLE_SCRIPT_URL)
    }
    document.head.appendChild(script)
}

function createVConsoleInstance() {
    if (!window.VConsole || window.__h5VConsoleInstance) {
        return
    }
    window.__h5VConsoleInstance = new window.VConsole()
    console.log('[h5-debug] vConsole 已启用')
}

function getQueryParamValue(key) {
    const searchValue = readQueryValue(window.location.search, key)
    if (searchValue) {
        return searchValue
    }
    const hashQuery = String(window.location.hash || '').split('?')[1] || ''
    return readQueryValue(hashQuery, key)
}

function readQueryValue(queryText, key) {
    if (typeof queryText !== 'string' || !queryText) {
        return ''
    }
    const normalizedQuery = queryText.replace(/^[?#&]/, '')
    if (!normalizedQuery) {
        return ''
    }
    const pairs = normalizedQuery.split('&')
    for (const pair of pairs) {
        if (!pair) {
            continue
        }
        const splitIndex = pair.indexOf('=')
        const rawKey = splitIndex >= 0 ? pair.slice(0, splitIndex) : pair
        if (safeDecode(rawKey) !== key) {
            continue
        }
        const rawValue = splitIndex >= 0 ? pair.slice(splitIndex + 1) : ''
        return safeDecode(rawValue).trim()
    }
    return ''
}

function safeDecode(value) {
    try {
        return decodeURIComponent(String(value || '').replace(/\+/g, ' '))
    } catch (error) {
        return String(value || '')
    }
}

function safeGetStorage(key) {
    try {
        return window.localStorage.getItem(key)
    } catch (error) {
        return ''
    }
}

function safeSetStorage(key, value) {
    try {
        window.localStorage.setItem(key, value)
    } catch (error) {
        // 忽略存储异常，避免影响页面正常使用。
    }
}

function safeRemoveStorage(key) {
    try {
        window.localStorage.removeItem(key)
    } catch (error) {
        // 忽略存储异常，避免影响页面正常使用。
    }
}