package com.medithings.vesiscan.managers

import androidx.compose.runtime.mutableIntStateOf
import androidx.compose.runtime.mutableStateListOf
import androidx.compose.runtime.mutableStateOf
import com.medithings.vesiscan.models.NirsMagResponse
import com.medithings.vesiscan.models.NirsMcjPacket
import com.medithings.vesiscan.models.NirsConstants
import com.medithings.vesiscan.BuildConfig
import com.medithings.vesiscan.models.NirsOxyResult

class NirsManager private constructor() {
    companion object {
        val instance: NirsManager by lazy { NirsManager() }
    }

    // State
    val isStreaming = mutableStateOf(false)
    val isCalibrated = mutableStateOf(false)
    val isFilterEnabled = mutableStateOf(true)

    // Current Values
    val currentOxy = mutableStateOf(NirsOxyResult.zero)
    val sampleCount = mutableIntStateOf(0)

    // Chart History
    val oxyHbO2History = mutableStateListOf<Double>()
    val oxyHbHistory = mutableStateListOf<Double>()

    // Internal
    val calcEngine = NirsCalcEngine()
    private val maxPoints = NirsConstants.maxHistoryPoints

    // Calibration
    fun setCalibrationGain(response: NirsMagResponse) {
        calcEngine.setGainFromMag(response)
        isCalibrated.value = true
    }

    // Process mcj Packet
    fun processMcjPacket(packet: NirsMcjPacket) {
        val result = calcEngine.process(packet.ledValues)
        currentOxy.value = result.oxyFiltered
        sampleCount.intValue++

        if (BuildConfig.DEBUG && (sampleCount.intValue <= 3 || sampleCount.intValue % 50 == 0)) {
            android.util.Log.d("NirsManager", "Sample #${sampleCount.intValue}: " +
                "hasGain=${calcEngine.hasGain}, " +
                "led[0..5]=${packet.ledValues.take(6)}, " +
                "degain[0..2]=${result.degain.take(3).map { "%.2f".format(it) }}, " +
                "oxy=StO2:${"%.1f".format(result.oxyFiltered.stO2)} HbO2:${"%.1f".format(result.oxyFiltered.hbO2)} HHb:${"%.1f".format(result.oxyFiltered.hb)}")
        }

        appendTrimming(oxyHbO2History, result.oxyFiltered.hbO2)
        appendTrimming(oxyHbHistory, result.oxyFiltered.hb)
    }

    // Controls
    fun toggleFilter() {
        isFilterEnabled.value = !isFilterEnabled.value
        calcEngine.isFilterEnabled = isFilterEnabled.value
        if (isFilterEnabled.value) calcEngine.resetFilter()
    }

    fun clearData() {
        oxyHbO2History.clear()
        oxyHbHistory.clear()
        currentOxy.value = NirsOxyResult.zero
        sampleCount.intValue = 0
        calcEngine.resetFilter()
    }

    fun startStreaming() {
        isStreaming.value = true
        calcEngine.resetFilter()
    }

    fun stopStreaming() {
        isStreaming.value = false
    }

    fun reset() {
        stopStreaming()
        clearData()
        isCalibrated.value = false
        calcEngine.clearGain()
    }

    // Helpers
    private fun appendTrimming(list: MutableList<Double>, value: Double) {
        list.add(value)
        while (list.size > maxPoints) list.removeAt(0)
    }
}