package eu.brassepc.fitnessdroid.data

import android.content.Context
import androidx.health.connect.client.HealthConnectClient
import androidx.health.connect.client.permission.HealthPermission
import androidx.health.connect.client.records.StepsRecord
import androidx.health.connect.client.request.AggregateRequest
import androidx.health.connect.client.time.TimeRangeFilter
import java.time.Instant
import java.time.LocalDate
import java.time.ZoneId

/**
 * Steg via Health Connect: läser dagens + gårdagens stegsumma (som andra
 * appar/telefonen loggat) och synkar upp till gym-API:t (upsertDailySteps).
 * Servern räknar sedan in stegen i kcal-mätarens telefondel och stegmålen.
 */
class StepsSync(
    private val context: Context,
    private val gymApi: GymApi,
) {
    val stepsPermission: String = HealthPermission.getReadPermission(StepsRecord::class)

    private var lastSyncMs = 0L

    /** SDK_UNAVAILABLE / SDK_UNAVAILABLE_PROVIDER_UPDATE_REQUIRED / SDK_AVAILABLE */
    fun sdkStatus(): Int = HealthConnectClient.getSdkStatus(context)

    fun isAvailable(): Boolean = sdkStatus() == HealthConnectClient.SDK_AVAILABLE

    suspend fun hasPermission(): Boolean {
        if (!isAvailable()) return false
        return runCatching {
            HealthConnectClient.getOrCreate(context)
                .permissionController.getGrantedPermissions()
                .contains(stepsPermission)
        }.getOrDefault(false)
    }

    /**
     * Läs och synka. Returnerar dagens steg, eller null om HC saknas /
     * behörighet inte getts. Fel sväljs (nästa synk försöker igen).
     */
    suspend fun syncNow(): Int? {
        if (!hasPermission()) return null
        val client = HealthConnectClient.getOrCreate(context)
        val zone = ZoneId.systemDefault()
        val today = LocalDate.now()
        var todaySteps: Int? = null

        for (day in listOf(today.minusDays(1), today)) {
            val startInstant = day.atStartOfDay(zone).toInstant()
            val endInstant = if (day == today) Instant.now()
            else day.plusDays(1).atStartOfDay(zone).toInstant()

            val steps = runCatching {
                val result = client.aggregate(
                    AggregateRequest(
                        metrics = setOf(StepsRecord.COUNT_TOTAL),
                        timeRangeFilter = TimeRangeFilter.between(startInstant, endInstant),
                    )
                )
                (result[StepsRecord.COUNT_TOTAL] ?: 0L).toInt()
            }.getOrNull() ?: continue

            if (day == today) todaySteps = steps
            runCatching {
                gymApi.upsertDailySteps(startInstant.toString(), steps)
            }
        }
        lastSyncMs = System.currentTimeMillis()
        return todaySteps
    }

    /** Synka högst var 10:e minut — anropas t.ex. när hemskärmen visas. */
    suspend fun syncThrottled() {
        if (System.currentTimeMillis() - lastSyncMs < 10 * 60_000) return
        syncNow()
    }
}