package com.jttools.datacontrol.data

import android.content.Context
import android.content.Intent
import android.net.Uri
import android.provider.Settings
import androidx.core.content.FileProvider
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.withContext
import org.json.JSONObject
import java.io.File
import java.net.HttpURLConnection
import java.net.URL

/**
 * Mise à jour via les Releases Gitea du dépôt (dernière release publiée + son asset .apk).
 * Le dépôt est public : aucun jeton n'est nécessaire.
 */
class UpdateManager(private val context: Context, private val currentVersion: String) {

    data class UpdateInfo(val versionName: String, val apkUrl: String, val changelog: String)

    sealed interface CheckResult {
        data object UpToDate : CheckResult
        data class Available(val info: UpdateInfo) : CheckResult
        data class Error(val message: String) : CheckResult
    }

    suspend fun check(): CheckResult = withContext(Dispatchers.IO) {
        try {
            val conn = open(RELEASES_URL)
            try {
                if (conn.responseCode != HttpURLConnection.HTTP_OK) {
                    return@withContext CheckResult.Error("HTTP ${conn.responseCode}")
                }
                val json = JSONObject(conn.inputStream.bufferedReader().use { it.readText() })
                val version = json.optString("tag_name").removePrefix("v")
                if (version.isBlank()) return@withContext CheckResult.Error("Release sans tag")

                val assets = json.optJSONArray("assets")
                var apkUrl = ""
                if (assets != null) {
                    for (i in 0 until assets.length()) {
                        val asset = assets.getJSONObject(i)
                        if (asset.optString("name").endsWith(".apk")) {
                            apkUrl = asset.optString("browser_download_url")
                            break
                        }
                    }
                }
                when {
                    !isNewer(version, currentVersion) -> CheckResult.UpToDate
                    apkUrl.isBlank() -> CheckResult.Error("Aucun APK dans la release v$version")
                    else -> CheckResult.Available(UpdateInfo(version, apkUrl, json.optString("body")))
                }
            } finally {
                conn.disconnect()
            }
        } catch (e: Exception) {
            CheckResult.Error(e.message ?: e.javaClass.simpleName)
        }
    }

    /** Télécharge l'APK dans le cache ; [onProgress] reçoit 0-100. Retourne le fichier ou lève une exception. */
    suspend fun download(info: UpdateInfo, onProgress: (Int) -> Unit): File = withContext(Dispatchers.IO) {
        val dir = File(context.cacheDir, "updates").apply { mkdirs() }
        dir.listFiles()?.forEach { it.delete() }
        val file = File(dir, "DataControl-${info.versionName}.apk")
        val conn = open(info.apkUrl)
        try {
            if (conn.responseCode != HttpURLConnection.HTTP_OK) error("HTTP ${conn.responseCode}")
            val total = conn.contentLengthLong
            var done = 0L
            conn.inputStream.use { input ->
                file.outputStream().use { output ->
                    val buf = ByteArray(32 * 1024)
                    var n: Int
                    while (input.read(buf).also { n = it } != -1) {
                        output.write(buf, 0, n)
                        done += n
                        if (total > 0) onProgress((done * 100 / total).toInt())
                    }
                }
            }
        } finally {
            conn.disconnect()
        }
        file
    }

    /** Vrai si l'installation a été lancée ; faux si l'utilisateur doit d'abord autoriser l'installation d'APK. */
    fun install(file: File): Boolean {
        if (!context.packageManager.canRequestPackageInstalls()) {
            context.startActivity(
                Intent(Settings.ACTION_MANAGE_UNKNOWN_APP_SOURCES, Uri.parse("package:${context.packageName}"))
                    .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
            )
            return false
        }
        val uri = FileProvider.getUriForFile(context, "${context.packageName}.fileprovider", file)
        context.startActivity(
            Intent(Intent.ACTION_VIEW)
                .setDataAndType(uri, "application/vnd.android.package-archive")
                .addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_ACTIVITY_NEW_TASK)
        )
        return true
    }

    private fun open(url: String): HttpURLConnection =
        (URL(url).openConnection() as HttpURLConnection).apply {
            connectTimeout = 15_000
            readTimeout = 30_000
            setRequestProperty("User-Agent", "DataControl/$currentVersion")
            setRequestProperty("Accept", "application/json, application/octet-stream")
        }

    companion object {
        const val RELEASES_URL = "https://git.tuxtech.fr/api/v1/repos/tuxgyver/DataControl/releases/latest"

        fun isNewer(remote: String, current: String): Boolean {
            val r = remote.split(".").map { it.toIntOrNull() ?: 0 }
            val c = current.split(".").map { it.toIntOrNull() ?: 0 }
            for (i in 0 until maxOf(r.size, c.size)) {
                val rv = r.getOrElse(i) { 0 }
                val cv = c.getOrElse(i) { 0 }
                if (rv != cv) return rv > cv
            }
            return false
        }
    }
}