package com.rippr.data

import android.content.Context
import androidx.room.Database
import androidx.room.Room
import androidx.room.RoomDatabase
import androidx.room.TypeConverter
import androidx.room.TypeConverters

class Converters {
    @TypeConverter
    fun toTripState(value: String): TripState = TripState.valueOf(value)

    @TypeConverter
    fun fromTripState(state: TripState): String = state.name
}

@Database(
    entities = [Trip::class, Segment::class, TrackPoint::class],
    version = 2,
    exportSchema = true,
)
@TypeConverters(Converters::class)
abstract class AppDatabase : RoomDatabase() {

    abstract fun tripDao(): TripDao
    abstract fun segmentDao(): SegmentDao
    abstract fun trackPointDao(): TrackPointDao

    companion object {
        @Volatile
        private var INSTANCE: AppDatabase? = null

        fun getDatabase(context: Context): AppDatabase =
            INSTANCE ?: synchronized(this) {
                INSTANCE ?: Room.databaseBuilder(
                    context.applicationContext,
                    AppDatabase::class.java,
                    "rippr_db"
                )
                    // A ride is unrecoverable if a write is lost to a crash mid-flush,
                    // but full sync on every insert at 2 Hz burns battery. WAL with
                    // NORMAL sync is the standard compromise and survives app crashes;
                    // only an OS-level crash can lose the last few points.
                    .setJournalMode(JournalMode.WRITE_AHEAD_LOGGING)
                    // No destructive fallback. Rides recorded from v2 onward are real
                    // data, so any future schema change MUST ship a Migration against the
                    // committed schemas/com.rippr.data.AppDatabase/2.json baseline.
                    // Reinstating fallbackToDestructiveMigration() here would silently
                    // delete every stored ride on the next version bump.
                    .build()
                    .also { INSTANCE = it }
            }

        /** Test seam — lets instrumented tests substitute an in-memory database. */
        fun overrideForTest(db: AppDatabase?) {
            INSTANCE = db
        }
    }
}