/*
 * Copyright © 2014-2020 The Android Password Store Authors. All Rights Reserved.
 * SPDX-License-Identifier: GPL-3.0-only
 */
@file:Suppress("DEPRECATION")

package com.zeapo.pwdstore

import android.content.Context
import android.content.SharedPreferences
import androidx.core.content.edit
import com.github.ajalt.timberkt.e
import com.github.ajalt.timberkt.i
import com.github.michaelbull.result.get
import com.github.michaelbull.result.runCatching
import com.zeapo.pwdstore.git.config.GitSettings
import com.zeapo.pwdstore.git.config.Protocol
import com.zeapo.pwdstore.git.sshj.SshKey
import com.zeapo.pwdstore.utils.PreferenceKeys
import com.zeapo.pwdstore.utils.getString
import com.zeapo.pwdstore.utils.sharedPrefs
import java.io.File
import java.net.URI

fun runMigrations(context: Context) {
    val sharedPrefs = context.sharedPrefs
    migrateToGitUrlBasedConfig(sharedPrefs)
    migrateToHideAll(sharedPrefs)
    migrateToSshKey(context, sharedPrefs)
}

private fun migrateToGitUrlBasedConfig(sharedPrefs: SharedPreferences) {
    val serverHostname = sharedPrefs.getString(PreferenceKeys.GIT_REMOTE_SERVER)
        ?: return
    i { "Migrating to URL-based Git config" }
    val serverPort = sharedPrefs.getString(PreferenceKeys.GIT_REMOTE_PORT) ?: ""
    val serverUser = sharedPrefs.getString(PreferenceKeys.GIT_REMOTE_USERNAME) ?: ""
    val serverPath = sharedPrefs.getString(PreferenceKeys.GIT_REMOTE_LOCATION) ?: ""
    val protocol = Protocol.fromString(sharedPrefs.getString(PreferenceKeys.GIT_REMOTE_PROTOCOL))

    // Whether we need the leading ssh:// depends on the use of a custom port.
    val hostnamePart = serverHostname.removePrefix("ssh://")
    val url = when (protocol) {
        Protocol.Ssh -> {
            val userPart = if (serverUser.isEmpty()) "" else "${serverUser.trimEnd('@')}@"
            val portPart =
                if (serverPort == "22" || serverPort.isEmpty()) "" else ":$serverPort"
            if (portPart.isEmpty()) {
                "$userPart$hostnamePart:$serverPath"
            } else {
                // Only absolute paths are supported with custom ports.
                if (!serverPath.startsWith('/'))
                    null
                else
                // We have to specify the ssh scheme as this is the only way to pass a custom
                // port.
                    "ssh://$userPart$hostnamePart$portPart$serverPath"
            }
        }
        Protocol.Https -> {
            val portPart =
                if (serverPort == "443" || serverPort.isEmpty()) "" else ":$serverPort"
            val pathPart = serverPath.trimStart('/', ':')
            val urlWithFreeEntryScheme = "$hostnamePart$portPart/$pathPart"
            val url = when {
                urlWithFreeEntryScheme.startsWith("https://") -> urlWithFreeEntryScheme
                urlWithFreeEntryScheme.startsWith("http://") -> urlWithFreeEntryScheme.replaceFirst("http", "https")
                else -> "https://$urlWithFreeEntryScheme"
            }
            runCatching {
                if (URI(url).rawAuthority != null)
                    url
                else
                    null
            }.get()
        }
    }

    sharedPrefs.edit {
        remove(PreferenceKeys.GIT_REMOTE_LOCATION)
        remove(PreferenceKeys.GIT_REMOTE_PORT)
        remove(PreferenceKeys.GIT_REMOTE_SERVER)
        remove(PreferenceKeys.GIT_REMOTE_USERNAME)
        remove(PreferenceKeys.GIT_REMOTE_PROTOCOL)
    }
    if (url == null || GitSettings.updateConnectionSettingsIfValid(
            newAuthMode = GitSettings.authMode,
            newUrl = url,
            newBranch = GitSettings.branch) != GitSettings.UpdateConnectionSettingsResult.Valid) {
        e { "Failed to migrate to URL-based Git config, generated URL is invalid" }
    }
}

private fun migrateToHideAll(sharedPrefs: SharedPreferences) {
    sharedPrefs.all[PreferenceKeys.SHOW_HIDDEN_FOLDERS] ?: return
    val isHidden = sharedPrefs.getBoolean(PreferenceKeys.SHOW_HIDDEN_FOLDERS, false)
    sharedPrefs.edit {
        remove(PreferenceKeys.SHOW_HIDDEN_FOLDERS)
        putBoolean(PreferenceKeys.SHOW_HIDDEN_CONTENTS, isHidden)
    }
}

private fun migrateToSshKey(context: Context, sharedPrefs: SharedPreferences) {
    val privateKeyFile = File(context.filesDir, ".ssh_key")
    if (sharedPrefs.contains(PreferenceKeys.USE_GENERATED_KEY) &&
        !SshKey.exists &&
        privateKeyFile.exists()) {
        // Currently uses a private key imported or generated with an old version of Password Store.
        // Generated keys come with a public key which the user should still be able to view after
        // the migration (not possible for regular imported keys), hence the special case.
        val isGeneratedKey = sharedPrefs.getBoolean(PreferenceKeys.USE_GENERATED_KEY, false)
        SshKey.useLegacyKey(isGeneratedKey)
        sharedPrefs.edit {
            remove(PreferenceKeys.USE_GENERATED_KEY)
        }
    }
}