package com.jovan.assistant.security

import com.jovan.assistant.data.AssistantState
import com.jovan.assistant.data.FirebaseRepo
import com.jovan.assistant.data.Prefs
import com.jovan.assistant.data.WakeStatus
import com.jovan.assistant.service.AssistantAccessibilityService

/**
 * Protective layer. Two independent counters inside a sliding window:
 *  - SUSPICIOUS (unauthenticated command, restricted-command attempt): 3 in 60s -> lock + block
 *  - ERROR (repeated action failures): 8 in 60s -> lock + block
 * While blocked, no voice command is executed. Lifting the block in the UI requires the account password.
 */
object SecurityGuard {
    enum class Severity { SUSPICIOUS, ERROR }

    private const val WINDOW_MS = 60_000L
    private const val BLOCK_MS = 5 * 60_000L
    private const val MAX_SUSPICIOUS = 3
    private const val MAX_ERRORS = 8

    private val suspicious = ArrayDeque<Long>()
    private val errors = ArrayDeque<Long>()

    fun isBlocked(): Boolean = System.currentTimeMillis() < Prefs.blockedUntil

    @Synchronized
    fun report(reason: String, severity: Severity = Severity.SUSPICIOUS) {
        val now = System.currentTimeMillis()
        val q = if (severity == Severity.SUSPICIOUS) suspicious else errors
        val max = if (severity == Severity.SUSPICIOUS) MAX_SUSPICIOUS else MAX_ERRORS
        q.addLast(now)
        while (q.isNotEmpty() && now - q.first() > WINDOW_MS) q.removeFirst()

        FirebaseRepo.log("SECURITY", reason, if (severity == Severity.SUSPICIOUS) "warn" else "info")
        if (q.size >= max) trigger("Too many ${severity.name.lowercase()} events: $reason")
    }

    private fun trigger(reason: String) {
        Prefs.blockedUntil = System.currentTimeMillis() + BLOCK_MS
        AssistantState.wakeStatus.value = WakeStatus.BLOCKED
        suspicious.clear(); errors.clear()
        AssistantAccessibilityService.instance?.lockScreen()
        FirebaseRepo.log("SECURITY", "PROTECTIVE BLOCK: $reason. Screen locked, commands blocked for 5 min.", "critical")
    }

    /** Call only after the password has been re-verified. */
    fun clearBlock() {
        Prefs.blockedUntil = 0L
        suspicious.clear(); errors.clear()
        FirebaseRepo.log("SECURITY", "Protective block lifted by user", "info")
    }
}