package de.patani.kettlebelltracker.viewmodels

import android.util.Log
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import de.patani.kettlebelltracker.data.local.TrainingSessionDao
import de.patani.kettlebelltracker.data.datastore.SettingsDataStore
import de.patani.kettlebelltracker.repositories.ApiRepository
import kotlinx.coroutines.Job
import kotlinx.coroutines.delay
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.asStateFlow
import kotlinx.coroutines.flow.first
import kotlinx.coroutines.flow.update
import kotlinx.coroutines.launch
import java.util.Date
import kotlin.math.min

data class TrainingState(
    val isTrainingRunning: Boolean = false,
    val remainingSeconds: Int = 0,
    val initialDurationSeconds: Int = 0,
    val setsDone: Int = 0,
    val goalSets: Int = 5,
    val repsPerSet: Int = 5,
    val progress: Float = 0.0f,
    val currentProgram: String = "clean_1.0",
    val currentBlockDay: Int = 1,
    val currentReps: Int = 5,
    val totalTrainingDays: Int = 0
)

class TrainingViewModel(
    private val dao: TrainingSessionDao,
    private val settingsDataStore: SettingsDataStore,
    private val apiRepository: ApiRepository,
    private val appUUID: String
) : ViewModel() {

    private val _trainingState = MutableStateFlow(TrainingState())
    val trainingState = _trainingState.asStateFlow()

    private var timerJob: Job? = null

    init {
        // Load initial state based on past trainings
        viewModelScope.launch {
            val trainingCount = dao.getTrainingCount().first()
            val initialState = calculateStateByDayCount(trainingCount)
            _trainingState.update {
                it.copy(
                    totalTrainingDays = trainingCount,
                    currentProgram = initialState.program,
                    currentBlockDay = initialState.blockDay,
                    currentReps = initialState.reps,
                    repsPerSet = initialState.reps
                )
            }
        }
    }

    fun startTraining() {
        if (_trainingState.value.isTrainingRunning) return

        viewModelScope.launch {
            val settings = settingsDataStore.settingsFlow.first()
            val durationSeconds = settings.trainingTimeMinutes * 60

            _trainingState.update {
                it.copy(
                    isTrainingRunning = true,
                    initialDurationSeconds = durationSeconds,
                    remainingSeconds = durationSeconds,
                    goalSets = settings.goalSets,
                    setsDone = 0,
                    progress = 0.0f
                )
            }
            startTimer()
        }
    }

    private fun startTimer() {
        timerJob?.cancel()
        timerJob = viewModelScope.launch {
            while (_trainingState.value.remainingSeconds > 0 && _trainingState.value.isTrainingRunning) {
                delay(1000)
                _trainingState.update { it.copy(remainingSeconds = it.remainingSeconds - 1) }
            }
            if (_trainingState.value.isTrainingRunning) {
                finishTraining()
            }
        }
    }

    fun completeSet() {
        if (!_trainingState.value.isTrainingRunning) return

        _trainingState.update {
            val newSetsDone = it.setsDone + 1
            val newProgress = if (it.goalSets > 0) {
                min(newSetsDone.toFloat() / it.goalSets.toFloat(), 1.0f)
            } else 0.0f
            it.copy(setsDone = newSetsDone, progress = newProgress)
        }
    }

    fun finishTraining() {
        timerJob?.cancel()
        if (!_trainingState.value.isTrainingRunning) return

        viewModelScope.launch {
            val state = _trainingState.value
            val settings = settingsDataStore.settingsFlow.first()

            val session = de.patani.kettlebelltracker.data.local.TrainingSession(
                date = Date(),
                sets = state.setsDone,
                weightLeft = settings.weightLeft,
                weightRight = settings.weightRight,
                repsPerSet = state.repsPerSet,
                duration = (state.initialDurationSeconds - state.remainingSeconds).toLong(),
                program = state.currentProgram,
                blockDay = state.currentBlockDay
            )

            dao.insert(session)
            apiRepository.sendTrainingData(session, appUUID)
            resetTraining()
        }
    }

    private suspend fun resetTraining() {
        val trainingCount = dao.getTrainingCount().first()
        val nextState = calculateStateByDayCount(trainingCount)
        _trainingState.value = TrainingState(
            totalTrainingDays = trainingCount,
            currentProgram = nextState.program,
            currentBlockDay = nextState.blockDay,
            currentReps = nextState.reps,
            repsPerSet = nextState.reps
        )
    }

    private fun calculateStateByDayCount(totalDays: Int): ProgramState {
        if (totalDays <= 0) {
            return ProgramState("clean_1.0", 1, 5)
        }

        val cycleIndex = (totalDays / 12) % 6
        val programs = listOf("clean_1.0", "snatch_1.0", "clean_1.1", "snatch_1.1", "clean_1.2", "snatch_1.2")
        val program = programs[cycleIndex]
        val blockDay = (totalDays % 3) + 1

        val repsMap = mapOf(
            "clean_1.0" to listOf(5, 6, 4),
            "clean_1.1" to listOf(6, 8, 7),
            "clean_1.2" to listOf(7, 9, 8),
            "snatch_1.0" to listOf(5, 6, 4),
            "snatch_1.1" to listOf(6, 8, 7),
            "snatch_1.2" to listOf(7, 9, 8)
        )

        val reps = repsMap[program]?.getOrNull(blockDay - 1) ?: 5
        return ProgramState(program, blockDay, reps)
    }

    data class ProgramState(val program: String, val blockDay: Int, val reps: Int)
}