package com.parkplants.map

import android.content.Context
import androidx.hilt.work.HiltWorker
import androidx.work.*
import dagger.assisted.Assisted
import dagger.assisted.AssistedInject

/**
 * Background WorkManager job that prefetches OSM map tiles for the park area.
 * Runs only when network is available. Safe to re-enqueue — skips cached tiles.
 */
@HiltWorker
class TilePrefetchWorker @AssistedInject constructor(
    @Assisted context: Context,
    @Assisted params: WorkerParameters,
) : CoroutineWorker(context, params) {

    override suspend fun doWork(): Result {
        return try {
            TilePrefetcher.prefetch(applicationContext) { done, total ->
                setProgressAsync(workDataOf(KEY_DONE to done, KEY_TOTAL to total))
            }
            Result.success()
        } catch (e: Exception) {
            // Non-fatal — map works online without prefetch
            Result.failure()
        }
    }

    companion object {
        const val WORK_NAME = "tile_prefetch"
        const val KEY_DONE  = "done"
        const val KEY_TOTAL = "total"

        fun enqueue(workManager: WorkManager) {
            workManager.enqueueUniqueWork(
                WORK_NAME,
                ExistingWorkPolicy.KEEP,
                OneTimeWorkRequestBuilder<TilePrefetchWorker>()
                    .setConstraints(
                        Constraints.Builder()
                            .setRequiredNetworkType(NetworkType.CONNECTED)
                            .build()
                    )
                    .build()
            )
        }
    }
}