package app.preferences

import app.extensions.defaultWindowPlacement
import app.viewmodels.TextDiffType
import app.viewmodels.textDiffTypeFromValue
import app.theme.ColorsScheme
import app.theme.Theme
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.StateFlow
import kotlinx.serialization.decodeFromString
import kotlinx.serialization.json.Json
import java.io.File
import java.util.prefs.Preferences
import javax.inject.Inject
import javax.inject.Singleton

private const val PREFERENCES_NAME = "GitnuroConfig"

private const val PREF_LATEST_REPOSITORIES_TABS_OPENED = "latestRepositoriesTabsOpened"
private const val PREF_LAST_OPENED_REPOSITORIES_PATH = "lastOpenedRepositoriesList"
private const val PREF_THEME = "theme"
private const val PREF_COMMITS_LIMIT = "commitsLimit"
private const val PREF_COMMITS_LIMIT_ENABLED = "commitsLimitEnabled"
private const val PREF_WINDOW_PLACEMENT = "windowsPlacement"
private const val PREF_CUSTOM_THEME = "customTheme"
private const val PREF_UI_SCALE = "ui_scale"
private const val PREF_DIFF_TYPE = "diffType"


private const val PREF_GIT_FF_MERGE = "gitFFMerge"

private const val DEFAULT_COMMITS_LIMIT = 1000
private const val DEFAULT_COMMITS_LIMIT_ENABLED = true
const val DEFAULT_UI_SCALE = -1f

@Singleton
class AppSettings @Inject constructor() {
    private val preferences: Preferences = Preferences.userRoot().node(PREFERENCES_NAME)

    private val _themeState = MutableStateFlow(theme)
    val themeState: StateFlow<Theme> = _themeState

    private val _commitsLimitEnabledFlow = MutableStateFlow(commitsLimitEnabled)
    val commitsLimitEnabledFlow: StateFlow<Boolean> = _commitsLimitEnabledFlow

    private val _ffMergeFlow = MutableStateFlow(ffMerge)
    val ffMergeFlow: StateFlow<Boolean> = _ffMergeFlow

    private val _commitsLimitFlow = MutableStateFlow(commitsLimit)
    val commitsLimitFlow: StateFlow<Int> = _commitsLimitFlow

    private val _customThemeFlow = MutableStateFlow<ColorsScheme?>(null)
    val customThemeFlow: StateFlow<ColorsScheme?> = _customThemeFlow

    private val _scaleUiFlow = MutableStateFlow(scaleUi)
    val scaleUiFlow: StateFlow<Float> = _scaleUiFlow

    private val _textDiffTypeFlow = MutableStateFlow(textDiffType)
    val textDiffTypeFlow: StateFlow<TextDiffType> = _textDiffTypeFlow

    var latestTabsOpened: String
        get() = preferences.get(PREF_LATEST_REPOSITORIES_TABS_OPENED, "")
        set(value) {
            preferences.put(PREF_LATEST_REPOSITORIES_TABS_OPENED, value)
        }

    var latestOpenedRepositoriesPath: String
        get() = preferences.get(PREF_LAST_OPENED_REPOSITORIES_PATH, "")
        set(value) {
            preferences.put(PREF_LAST_OPENED_REPOSITORIES_PATH, value)
        }

    var theme: Theme
        get() {
            val lastTheme = preferences.get(PREF_THEME, Theme.DARK.toString())
            return try {
                Theme.valueOf(lastTheme)
            } catch (ex: Exception) {
                ex.printStackTrace()
                Theme.DARK
            }
        }
        set(value) {
            preferences.put(PREF_THEME, value.toString())
            _themeState.value = value
        }

    var commitsLimitEnabled: Boolean
        get() {
            return preferences.getBoolean(PREF_COMMITS_LIMIT_ENABLED, DEFAULT_COMMITS_LIMIT_ENABLED)
        }
        set(value) {
            preferences.putBoolean(PREF_COMMITS_LIMIT_ENABLED, value)
            _commitsLimitEnabledFlow.value = value
        }

    var scaleUi: Float
        get() {
            return preferences.getFloat(PREF_UI_SCALE, DEFAULT_UI_SCALE)
        }
        set(value) {
            preferences.putFloat(PREF_UI_SCALE, value)
            _scaleUiFlow.value = value
        }

    /**
     * Property that decides if the merge should fast-forward when possible
     */
    var ffMerge: Boolean
        get() {
            return preferences.getBoolean(PREF_GIT_FF_MERGE, true)
        }
        set(value) {
            preferences.putBoolean(PREF_GIT_FF_MERGE, value)
            _ffMergeFlow.value = value
        }

    var commitsLimit: Int
        get() {
            return preferences.getInt(PREF_COMMITS_LIMIT, DEFAULT_COMMITS_LIMIT)
        }
        set(value) {
            preferences.putInt(PREF_COMMITS_LIMIT, value)
            _commitsLimitFlow.value = value
        }

    var windowPlacement: WindowsPlacementPreference
        get() {
            val placement = preferences.getInt(PREF_WINDOW_PLACEMENT, defaultWindowPlacement.value)

            return WindowsPlacementPreference(placement)
        }
        set(placement) {
            preferences.putInt(PREF_WINDOW_PLACEMENT, placement.value)
        }

    var textDiffType: TextDiffType
        get() {
            val diffTypeValue = preferences.getInt(PREF_DIFF_TYPE, TextDiffType.UNIFIED.value)

            return textDiffTypeFromValue(diffTypeValue)
        }
        set(placement) {
            preferences.putInt(PREF_DIFF_TYPE, placement.value)

            _textDiffTypeFlow.value = textDiffType
        }

    fun saveCustomTheme(filePath: String) {
        try {
            val file = File(filePath)
            val content = file.readText()

            Json.decodeFromString<ColorsScheme>(content) // Load to see if it's valid (it will crash if not)

            preferences.put(PREF_CUSTOM_THEME, content)
            loadCustomTheme()
        } catch (ex: Exception) {
            ex.printStackTrace()
        }
    }

    fun loadCustomTheme() {
        val themeJson = preferences.get(PREF_CUSTOM_THEME, null)
        if (themeJson != null) {
            _customThemeFlow.value = Json.decodeFromString<ColorsScheme>(themeJson)
        }
    }
}