import request from '@/utils/request.js'

let hasCheckedVersionThisLaunch = false
export const IOS_APP_STORE_URL = 'https://apps.apple.com/cn/app/%E6%B5%B7%E8%AF%8A%E5%BA%B7%E9%81%93/id6762694057'

/**
 * 版本检查接口要求的平台字段：iOS 传 ios，Android 传 Android。
 */
export function resolveVersionCheckPlatform() {
    const platform = String(uni.getSystemInfoSync().platform || '').toLowerCase()
    if (platform === 'android') {
        return 'Android'
    }
    return 'ios'
}

/**
 * 去掉展示文案里的 V 前缀，统一版本号格式。
 */
export function normalizeVersionText(value) {
    if (typeof value !== 'string') {
        return ''
    }
    const trimmedValue = value.trim()
    if (!trimmedValue) {
        return ''
    }
    return trimmedValue.replace(/^[vV]/, '')
}

/**
 * 检查 APP 最新版本信息。
 */
export function checkAppVersion(showLoading = true) {
    return request.get('/api/app/version/check', { platform: resolveVersionCheckPlatform() }, false, showLoading)
}

/**
 * 按真实接口结构归一化版本检查数据。
 */
export function normalizeVersionCheckData(data) {
    const source = data && typeof data === 'object' ? data : {}
    const rawDownloadUrl = typeof source.downloadUrl === 'string' ? source.downloadUrl.trim() : ''
    return {
        hasUpdate: Boolean(source.hasUpdate),
        latestVersionNo: normalizeVersionText(source.latestVersionNo),
        latestVersionCode: Number.isFinite(Number(source.latestVersionCode)) ? Number(source.latestVersionCode) : null,
        forceUpdate: Boolean(source.forceUpdate),
        updateNotice: typeof source.updateNotice === 'string' ? source.updateNotice.trim() : '',
        downloadUrl: rawDownloadUrl.replace(/^`|`$/g, ''),
    }
}

/**
 * 比较当前版本与最新版本是否真的存在升级。
 * 即使后端误返回 hasUpdate=true，只要版本号相同，前端也不再弹更新提示。
 */
export function shouldShowVersionUpdate(currentVersion, latestVersion) {
    const safeCurrentVersion = normalizeVersionText(currentVersion)
    const safeLatestVersion = normalizeVersionText(latestVersion)
    if (!safeCurrentVersion || !safeLatestVersion) {
        return false
    }
    if (safeCurrentVersion === safeLatestVersion) {
        return false
    }
    return compareVersionText(safeCurrentVersion, safeLatestVersion) < 0
}

/**
 * 优先读取运行时版本号，取不到时回退 manifest 配置版本。
 */
export function resolveRuntimeVersion(fallbackVersion = '') {
    // #ifdef APP-PLUS
    try {
        const runtimeVersion = typeof plus !== 'undefined' && plus.runtime ? normalizeVersionText(plus.runtime.version) : ''
        if (runtimeVersion) {
            return runtimeVersion
        }
    } catch (e) {
        console.warn('[app-version] 读取运行时版本失败:', e)
    }
    // #endif
    return normalizeVersionText(fallbackVersion)
}

/**
 * 当前 App 运行周期内是否还需要自动检查版本。
 * 返回 true 时会顺便占用这次检查机会，确保只触发一次。
 */
export function shouldAutoCheckVersionOnLaunch() {
    if (hasCheckedVersionThisLaunch) {
        return false
    }
    hasCheckedVersionThisLaunch = true
    return true
}

/**
 * 统一处理版本更新动作。
 * - Android：下载 APK 后调用系统安装
 * - iOS：优先跳转 App Store
 */
export function startVersionUpdate(downloadUrl, onProgress) {
    const safeDownloadUrl = typeof downloadUrl === 'string' ? downloadUrl.trim() : ''
    if (!safeDownloadUrl) {
        uni.showToast({
            title: '下载地址缺失',
            icon: 'none',
        })
        return Promise.reject(new Error('downloadUrl is empty'))
    }

    // #ifdef APP-PLUS
    const platform = String(uni.getSystemInfoSync().platform || '').toLowerCase()
    if (platform !== 'android') {
        notifyVersionUpdateProgress(onProgress, {
            status: 'redirecting',
            percent: 0,
            text: '前往 App Store',
        })
        plus.runtime.openURL(resolveIosUpdateUrl(safeDownloadUrl))
        return Promise.resolve()
    }
    return downloadAndInstallAndroidApk(safeDownloadUrl, onProgress)
    // #endif

    // #ifndef APP-PLUS
    uni.showToast({
        title: '请在APP内执行更新',
        icon: 'none',
    })
    return Promise.resolve()
    // #endif
}

/**
 * iOS 更新地址统一转成 App Store 可识别的链接。
 * 优先使用 itms-apps:// 协议直接拉起 App Store。
 */
function resolveIosUpdateUrl(downloadUrl) {
    const candidateUrl = IOS_APP_STORE_URL || downloadUrl
    if (typeof candidateUrl !== 'string') {
        return ''
    }
    const safeDownloadUrl = candidateUrl.trim()
    if (!safeDownloadUrl) {
        return ''
    }
    if (safeDownloadUrl.startsWith('itms-apps://')) {
        return safeDownloadUrl
    }
    if (safeDownloadUrl.includes('apps.apple.com') || safeDownloadUrl.includes('itunes.apple.com')) {
        return safeDownloadUrl.replace(/^https?:\/\//i, 'itms-apps://')
    }
    return safeDownloadUrl
}

/**
 * Android 端下载 APK 后拉起系统安装。
 */
function downloadAndInstallAndroidApk(downloadUrl, onProgress) {
    return new Promise((resolve, reject) => {
        try {
            const downloadTarget = `_doc/update/app-release-${Date.now()}.apk`
            notifyVersionUpdateProgress(onProgress, {
                status: 'downloading',
                percent: 0,
                text: '正在下载 0%',
            })
            const downloadTask = plus.downloader.createDownload(
                downloadUrl,
                {
                    filename: downloadTarget,
                },
                (download, status) => {
                    if (status !== 200 || !download || !download.filename) {
                        uni.showToast({
                            title: '下载更新失败',
                            icon: 'none',
                        })
                        notifyVersionUpdateProgress(onProgress, {
                            status: 'failed',
                            percent: 0,
                            text: '立即更新',
                        })
                        reject(new Error(`download failed: ${status}`))
                        return
                    }
                    notifyVersionUpdateProgress(onProgress, {
                        status: 'downloaded',
                        percent: 100,
                        text: '安装中...',
                    })
                    installDownloadedApk(download.filename, resolve, reject, onProgress)
                }
            )
            // 监听下载进度，把百分比回传给页面，直接展示到弹窗按钮文案。
            downloadTask.addEventListener('statechanged', (task) => {
                const totalSize = Number(task && task.totalSize) || 0
                const downloadedSize = Number(task && task.downloadedSize) || 0
                if (totalSize <= 0 || downloadedSize < 0) {
                    return
                }
                const percent = Math.min(99, Math.max(0, Math.floor((downloadedSize / totalSize) * 100)))
                notifyVersionUpdateProgress(onProgress, {
                    status: 'downloading',
                    percent,
                    text: `正在下载 ${percent}%`,
                })
            })
            downloadTask.start()
        } catch (e) {
            uni.showToast({
                title: '启动下载失败',
                icon: 'none',
            })
            notifyVersionUpdateProgress(onProgress, {
                status: 'failed',
                percent: 0,
                text: '立即更新',
            })
            reject(e)
        }
    })
}

/**
 * APK 下载完成后，交给系统安装器处理。
 */
function installDownloadedApk(filePath, resolve, reject, onProgress) {
    try {
        notifyVersionUpdateProgress(onProgress, {
            status: 'installing',
            percent: 100,
            text: '安装中...',
        })
        // 这里直接交给系统安装器处理，用户确认后即可安装新版本。
        plus.runtime.install(
            filePath,
            {},
            () => {
                notifyVersionUpdateProgress(onProgress, {
                    status: 'completed',
                    percent: 100,
                    text: '立即更新',
                })
                resolve(filePath)
            },
            (error) => {
                console.error('[app-version] 安装 APK 失败:', error)
                uni.showToast({
                    title: '拉起安装失败',
                    icon: 'none',
                })
                notifyVersionUpdateProgress(onProgress, {
                    status: 'failed',
                    percent: 100,
                    text: '立即更新',
                })
                reject(error)
            }
        )
    } catch (e) {
        uni.showToast({
            title: '拉起安装失败',
            icon: 'none',
        })
        notifyVersionUpdateProgress(onProgress, {
            status: 'failed',
            percent: 100,
            text: '立即更新',
        })
        reject(e)
    }
}

/**
 * 通知页面当前更新进度，页面可把文案直接展示到弹窗按钮。
 */
function notifyVersionUpdateProgress(onProgress, progressInfo) {
    if (typeof onProgress !== 'function') {
        return
    }
    try {
        onProgress(progressInfo)
    } catch (e) {
        console.warn('[app-version] 更新进度回调失败:', e)
    }
}

/**
 * 逐段比较版本号，返回值：
 * -1：current < latest
 *  0：current = latest
 *  1：current > latest
 */
function compareVersionText(currentVersion, latestVersion) {
    const currentParts = splitVersionText(currentVersion)
    const latestParts = splitVersionText(latestVersion)
    const maxLength = Math.max(currentParts.length, latestParts.length)
    for (let index = 0; index < maxLength; index += 1) {
        const currentPart = currentParts[index] || 0
        const latestPart = latestParts[index] || 0
        if (currentPart < latestPart) {
            return -1
        }
        if (currentPart > latestPart) {
            return 1
        }
    }
    return 0
}

/**
 * 把版本号拆成数字数组，便于逐段比较。
 */
function splitVersionText(versionText) {
    return String(versionText || '')
        .split('.')
        .map((item) => Number.parseInt(item, 10))
        .filter((item) => Number.isFinite(item))
}