Questionnaire-App/app/src/main/java/com/dano/test1/DatabaseUploader.kt

package com.dano.test1

import android.content.Context
import android.database.sqlite.SQLiteDatabase
import android.util.Base64
import android.util.Log
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
import android.database.Cursor
import okhttp3.*
import okhttp3.MediaType.Companion.toMediaTypeOrNull
import okhttp3.RequestBody.Companion.asRequestBody
import org.json.JSONArray
import org.json.JSONObject
import java.io.File
import java.io.IOException
import kotlin.system.exitProcess

object DatabaseUploader {

    private const val DB_NAME = "questionnaire_database"
    private const val SERVER_FULL_URL = "http://49.13.157.44/uploadFull.php"
    private const val SERVER_DELTA_URL = "http://49.13.157.44/uploadDelta.php"
    private const val SERVER_CHECK_URL = "http://49.13.157.44/checkDatabaseExists.php"
    private const val API_TOKEN = "MEIN_SUPER_GEHEIMES_TOKEN_12345"

    private val client = OkHttpClient()

    fun uploadDatabase(context: Context) {
        CoroutineScope(Dispatchers.IO).launch {
            try {
                val dbFile = context.getDatabasePath(DB_NAME)
                if (!dbFile.exists()) {
                    Log.e("UPLOAD", "Datenbankdatei existiert nicht: ${dbFile.absolutePath}")
                    return@launch
                }

                // WAL-Checkpoint
                try {
                    val db = SQLiteDatabase.openDatabase(
                        dbFile.absolutePath,
                        null,
                        SQLiteDatabase.OPEN_READWRITE
                    )
                    db.rawQuery("PRAGMA wal_checkpoint(FULL);", null).use { cursor ->
                        if (cursor.moveToFirst()) {
                            try {
                                Log.d("UPLOAD", "WAL-Checkpoint result: ${cursor.getInt(0)}")
                            } catch (_: Exception) {}
                        }
                    }
                    db.close()
                    Log.d("UPLOAD", "WAL-Checkpoint erfolgreich.")
                } catch (e: Exception) {
                    Log.e("UPLOAD", "Fehler beim WAL-Checkpoint", e)
                }

                val exists = checkDatabaseExists()
                if (exists) {
                    Log.d("UPLOAD", "Server-Datenbank vorhanden → Delta-Upload")
                    uploadDelta(dbFile)
                } else {
                    Log.d("UPLOAD", "Keine Server-Datenbank → Full-Upload")
                    uploadFull(dbFile)
                }

            } catch (e: Exception) {
                Log.e("UPLOAD", "Fehler beim Hochladen der DB", e)
            }
        }
    }

    private fun checkDatabaseExists(): Boolean {
        return try {
            val request = Request.Builder()
                .url(SERVER_CHECK_URL)
                .get()
                .build()

            client.newCall(request).execute().use { response ->
                if (!response.isSuccessful) {
                    Log.e("UPLOAD", "checkDatabaseExists HTTP error: ${response.code}")
                    return false
                }
                val body = response.body?.string() ?: return false
                try {
                    val j = JSONObject(body)
                    j.optBoolean("exists", false)
                } catch (e: Exception) {
                    body.contains("exists", ignoreCase = true)
                }
            }
        } catch (e: Exception) {
            Log.e("UPLOAD", "Fehler bei Server-Prüfung", e)
            false
        }
    }

    private fun uploadFull(file: File) {
        val requestBody = MultipartBody.Builder()
            .setType(MultipartBody.FORM)
            .addFormDataPart(
                "file", file.name,
                file.asRequestBody("application/octet-stream".toMediaTypeOrNull())
            )
            .addFormDataPart("token", API_TOKEN)
            .build()

        val request = Request.Builder()
            .url(SERVER_FULL_URL)
            .post(requestBody)
            .build()

        client.newCall(request).enqueue(serverCallback(file))
    }

    private fun uploadDelta(file: File) {
        try {
            val db = SQLiteDatabase.openDatabase(file.absolutePath, null, SQLiteDatabase.OPEN_READONLY)

            val data = JSONObject().apply {
                put("clients", queryToJsonArray(db, "SELECT clientCode FROM clients"))
                put("questionnaires", queryToJsonArray(db, "SELECT id FROM questionnaires"))
                put("questions", queryToJsonArray(db, "SELECT questionId, questionnaireId, question FROM questions"))
                put("answers", queryToJsonArray(db, "SELECT clientCode, questionId, answerValue FROM answers"))
                put("completed_questionnaires",
                    queryToJsonArray(db, "SELECT clientCode, questionnaireId, timestamp, isDone, sumPoints FROM completed_questionnaires")
                )
            }

            db.close()

            val requestBody = MultipartBody.Builder()
                .setType(MultipartBody.FORM)
                .addFormDataPart("token", API_TOKEN)
                .addFormDataPart("data", data.toString())
                .build()

            val request = Request.Builder()
                .url(SERVER_DELTA_URL)
                .post(requestBody)
                .build()

            client.newCall(request).enqueue(serverCallback(file))

        } catch (e: Exception) {
            Log.e("UPLOAD", "Fehler beim Delta-Upload", e)
        }
    }

    private fun queryToJsonArray(db: SQLiteDatabase, query: String): JSONArray {
        val cursor = db.rawQuery(query, null)
        val jsonArray = JSONArray()
        cursor.use {
            val columnNames = it.columnNames
            while (it.moveToNext()) {
                val obj = JSONObject()
                for (col in columnNames) {
                    val idx = it.getColumnIndex(col)
                    if (idx >= 0) {
                        when (it.getType(idx)) {
                            Cursor.FIELD_TYPE_INTEGER -> obj.put(col, it.getLong(idx))
                            Cursor.FIELD_TYPE_FLOAT -> obj.put(col, it.getDouble(idx))
                            Cursor.FIELD_TYPE_STRING -> obj.put(col, it.getString(idx))
                            Cursor.FIELD_TYPE_NULL -> obj.put(col, JSONObject.NULL)
                            Cursor.FIELD_TYPE_BLOB -> {
                                val blob = it.getBlob(idx)
                                obj.put(col, Base64.encodeToString(blob, Base64.NO_WRAP))
                            }
                            else -> obj.put(col, it.getString(idx))
                        }
                    }
                }
                jsonArray.put(obj)
            }
        }
        return jsonArray
    }

    private fun serverCallback(file: File) = object : Callback {
        override fun onFailure(call: Call, e: IOException) {
            Log.e("UPLOAD", "Upload fehlgeschlagen: ${e.message}")
        }

        override fun onResponse(call: Call, response: Response) {
            val body = try { response.body?.string() ?: "Keine Response" } catch (e: Exception) { "Fehler beim Lesen der Response: ${e.message}" }
            if (response.isSuccessful) {
                Log.d("UPLOAD", "Upload erfolgreich: $body")
                if (file.delete()) {
                    Log.d("UPLOAD", "Lokale DB gelöscht.")
                    exitProcess(0)
                } else {
                    Log.e("UPLOAD", "Löschen der lokalen DB fehlgeschlagen.")
                }
            } else {
                Log.e("UPLOAD", "Upload fehlgeschlagen: ${response.code} $body")
            }
        }
    }
}