/**
 * @file CameraPermissions.kt
 * @brief Runtime-permission requirements for the bowling camera feature.
 */
package com.example.jnicpp.bowling

import android.Manifest
import android.content.Context
import android.content.pm.PackageManager
import android.os.Build
import androidx.core.content.ContextCompat

/**
 * @brief Single source of truth for which runtime permissions this feature
 *        needs and whether they're currently granted.
 *
 * The actual request flow (which must be owned by an Activity/Fragment via
 * ActivityResultContracts) lives in [BowlingCameraActivity]; this object
 * just centralizes the "what" so both the manifest expectations and the
 * request flow can't drift apart.
 */
object CameraPermissions {

    /**
     * @brief The permissions this feature requires on the current device.
     *
     * Always includes camera and microphone. Also includes
     * `WRITE_EXTERNAL_STORAGE` on API 28 and below, since scoped storage
     * (API 29+) lets an app insert into MediaStore's shared Movies
     * collection without it, but below that it's required to save the
     * recorded video into the gallery.
     */
    val REQUIRED: Array<String> = buildList {
        add(Manifest.permission.CAMERA)
        add(Manifest.permission.RECORD_AUDIO)
        if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
            add(Manifest.permission.WRITE_EXTERNAL_STORAGE)
        }
    }.toTypedArray()

    /**
     * @brief Checks whether every permission in [REQUIRED] is currently granted.
     * @param context Context used to query permission state.
     * @return true if all required permissions are granted, false otherwise.
     */
    fun allGranted(context: Context): Boolean =
        REQUIRED.all { permission ->
            ContextCompat.checkSelfPermission(context, permission) == PackageManager.PERMISSION_GRANTED
        }

    /**
     * @brief Lists which of [REQUIRED] are not currently granted.
     * @param context Context used to query permission state.
     * @return The subset of [REQUIRED] that is not yet granted; empty if all are granted.
     */
    @Suppress("unused")
    fun missing(context: Context): List<String> =
        REQUIRED.filter { permission ->
            ContextCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED
        }
}