package com.dmc.callcrm.data

import android.Manifest
import android.content.Context
import android.content.pm.PackageManager
import android.os.Build
import android.telecom.TelecomManager
import android.telephony.SubscriptionManager
import android.telephony.TelephonyManager
import androidx.core.content.ContextCompat

/**
 * Converts the SIM slot index chosen at registration (Prefs.simSlot: 0, 1, ... or
 * -1 if unset) into the CallLog.Calls.PHONE_ACCOUNT_ID string actually stored on
 * each call log row, so a dual-SIM phone can be filtered down to just the
 * registered SIM everywhere: server sync (Syncer.kt), recording matching
 * (RecordingScanner.kt), and the in-app Call History/Analytics/Contacts screens
 * (CallStats.kt).
 *
 * Returns null whenever it can't be resolved (no slot configured, permission
 * missing, older API level, OEM quirk, etc.) — every caller treats null as
 * "don't filter," so a resolution failure never hides every call on the phone.
 */
object SimUtil {

    fun resolvePhoneAccountId(ctx: Context, slot: Int): String? {
        if (slot < 0) return null
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) return null
        if (ContextCompat.checkSelfPermission(ctx, Manifest.permission.READ_PHONE_STATE) !=
            PackageManager.PERMISSION_GRANTED) return null

        return try {
            val subManager = ctx.getSystemService(SubscriptionManager::class.java) ?: return null
            val subs = subManager.activeSubscriptionInfoList ?: return null
            val match = subs.firstOrNull { it.simSlotIndex == slot } ?: return null

            val telecomManager = ctx.getSystemService(TelecomManager::class.java) ?: return null
            val accounts = telecomManager.callCapablePhoneAccounts ?: return null
            val baseTelephony = ctx.getSystemService(TelephonyManager::class.java) ?: return null

            for (handle in accounts) {
                val subId = try {
                    baseTelephony.createForPhoneAccountHandle(handle)?.subscriptionId
                } catch (_: Exception) { null }
                if (subId != null && subId == match.subscriptionId) return handle.id
            }
            null
        } catch (_: Exception) { null }
    }
}