package data

import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.StateFlow
import kotlinx.coroutines.flow.asStateFlow
import org.json.JSONObject
import java.io.File
import java.nio.file.AtomicMoveNotSupportedException
import java.nio.file.Files
import java.nio.file.StandardCopyOption
import java.util.concurrent.ConcurrentHashMap

// Font sizes offered in the settings dialog (whole sizes only, same range as QuickClaude)
const val MIN_FONT_SIZE = 10
const val MAX_FONT_SIZE = 18

private fun pickerFontSize(size: Float): Float =
    Math.round(size).coerceIn(MIN_FONT_SIZE, MAX_FONT_SIZE).toFloat()

data class WindowDisplaySettings(
    val backgroundAlpha: Float = 0.85f,   // 0f = fully transparent, 1f = fully opaque
    val textColorMircIndex: Int = 0,   // index into the standard mIRC palette; 0 = white
    val fontSize: Float = 14f,
    val fontId: String = "monospace",   // see ui/AppFonts.kt; unknown/missing ids fall back to monospace
    val showUserList: Boolean = true,
    val mentionHighlightColorArgb: Int = 0x40FFA500.toInt(),   // translucent orange
    val nickColorsEnabled: Boolean = true,
    val showImagePreviews: Boolean = false   // opt-in: auto-loading images reveals your IP to the host
)

/**
 * A window's last floating position and size, in dp (which Compose Desktop maps 1:1 to
 * AWT's logical screen coordinates). Every field is optional in window_prefs.json, so files
 * written before this existed still load - a window with no saved bounds just gets a
 * cascaded default (see ui/WindowPlacement.kt).
 */
data class WindowBounds(
    val x: Float?,
    val y: Float?,
    val width: Float?,
    val height: Float?
)

/**
 * Desktop equivalent of the Android DataStore-backed repository. Settings for every
 * buffer are kept as one JSON file (rootDir/window_prefs.json), keyed by buffer storage
 * id, loaded once at startup and rewritten on every change. Each buffer's settings are
 * exposed as a StateFlow so every open window for that buffer updates live, same as
 * DataStore's Flow did on Android.
 *
 * Window bounds live in the same JSON object per key (windowX/windowY/windowWidth/
 * windowHeight) but are kept out of the display-settings StateFlow, so moving or resizing
 * a window doesn't recompose its content.
 */
class WindowPrefsRepository(rootDir: File) {

    private val file = File(rootDir, "window_prefs.json")
    private val lock = Any()
    private val flows = ConcurrentHashMap<String, MutableStateFlow<WindowDisplaySettings>>()
    private val stored = mutableMapOf<String, WindowDisplaySettings>()
    private val storedBounds = mutableMapOf<String, WindowBounds>()

    init {
        loadAll()
    }

    fun settingsFor(bufferKeyId: String): StateFlow<WindowDisplaySettings> = flowFor(bufferKeyId).asStateFlow()

    fun setAlpha(bufferKeyId: String, alpha: Float) = update(bufferKeyId) { it.copy(backgroundAlpha = alpha) }

    fun setTextColorMircIndex(bufferKeyId: String, index: Int) = update(bufferKeyId) { it.copy(textColorMircIndex = index) }

    fun setFontSize(bufferKeyId: String, fontSize: Float) = update(bufferKeyId) { it.copy(fontSize = pickerFontSize(fontSize)) }

    fun setFontId(bufferKeyId: String, fontId: String) = update(bufferKeyId) { it.copy(fontId = fontId) }

    fun setShowUserList(bufferKeyId: String, show: Boolean) = update(bufferKeyId) { it.copy(showUserList = show) }

    fun setMentionHighlightColor(bufferKeyId: String, colorArgb: Int) = update(bufferKeyId) { it.copy(mentionHighlightColorArgb = colorArgb) }

    fun setNickColorsEnabled(bufferKeyId: String, enabled: Boolean) = update(bufferKeyId) { it.copy(nickColorsEnabled = enabled) }

    fun setShowImagePreviews(bufferKeyId: String, show: Boolean) = update(bufferKeyId) { it.copy(showImagePreviews = show) }

    fun boundsFor(bufferKeyId: String): WindowBounds? = synchronized(lock) { storedBounds[bufferKeyId] }

    fun setWindowBounds(bufferKeyId: String, bounds: WindowBounds) {
        synchronized(lock) {
            if (storedBounds[bufferKeyId] == bounds) return
            storedBounds[bufferKeyId] = bounds
            persist()
        }
    }

    private fun flowFor(bufferKeyId: String): MutableStateFlow<WindowDisplaySettings> =
        flows.getOrPut(bufferKeyId) { MutableStateFlow(synchronized(lock) { stored[bufferKeyId] } ?: WindowDisplaySettings()) }

    private fun update(bufferKeyId: String, transform: (WindowDisplaySettings) -> WindowDisplaySettings) {
        synchronized(lock) {
            val updated = transform(stored[bufferKeyId] ?: WindowDisplaySettings())
            stored[bufferKeyId] = updated
            flowFor(bufferKeyId).value = updated
            persist()
        }
    }

    private fun JSONObject.optFloatOrNull(key: String): Float? =
        if (has(key) && !isNull(key)) optDouble(key).toFloat().takeIf { !it.isNaN() } else null

    private fun loadAll() {
        if (!file.exists()) return
        try {
            val obj = JSONObject(file.readText())
            obj.keys().forEach { key ->
                val o = obj.getJSONObject(key)
                stored[key] = WindowDisplaySettings(
                    backgroundAlpha = o.optDouble("backgroundAlpha", 0.85).toFloat(),
                    textColorMircIndex = o.optInt("textColorMircIndex", 0),
                    // Sizes saved by the old slider (any value from 10 to 24) round to the nearest picker size
                    fontSize = pickerFontSize(o.optDouble("fontSize", 14.0).toFloat()),
                    fontId = o.optString("fontId", "monospace"),
                    showUserList = o.optBoolean("showUserList", true),
                    mentionHighlightColorArgb = o.optLong("mentionHighlightColorArgb", 0x40FFA500L).toInt(),
                    nickColorsEnabled = o.optBoolean("nickColorsEnabled", true),
                    showImagePreviews = o.optBoolean("showImagePreviews", false)
                )
                val bounds = WindowBounds(
                    x = o.optFloatOrNull("windowX"),
                    y = o.optFloatOrNull("windowY"),
                    width = o.optFloatOrNull("windowWidth"),
                    height = o.optFloatOrNull("windowHeight")
                )
                if (bounds != WindowBounds(null, null, null, null)) storedBounds[key] = bounds
            }
        } catch (e: Exception) {
            stored.clear()
            storedBounds.clear()
        }
    }

    // Written to a temp file and moved into place, same as MessageHistoryRepository - this
    // file is now rewritten every time a window is moved or resized, so a crash mid-write
    // must not be able to leave a truncated file (which loadAll would read as "no settings
    // at all" and the next save would make permanent).
    private fun persist() {
        val obj = JSONObject()
        (stored.keys + storedBounds.keys).forEach { key ->
            obj.put(key, JSONObject().apply {
                stored[key]?.let { settings ->
                    put("backgroundAlpha", settings.backgroundAlpha)
                    put("textColorMircIndex", settings.textColorMircIndex)
                    put("fontSize", settings.fontSize)
                    put("fontId", settings.fontId)
                    put("showUserList", settings.showUserList)
                    put("mentionHighlightColorArgb", settings.mentionHighlightColorArgb)
                    put("nickColorsEnabled", settings.nickColorsEnabled)
                    put("showImagePreviews", settings.showImagePreviews)
                }
                storedBounds[key]?.let { bounds ->
                    bounds.x?.let { put("windowX", it) }
                    bounds.y?.let { put("windowY", it) }
                    bounds.width?.let { put("windowWidth", it) }
                    bounds.height?.let { put("windowHeight", it) }
                }
            })
        }
        file.parentFile?.mkdirs()
        val tmp = File(file.parentFile, "${file.name}.tmp")
        tmp.writeText(obj.toString())
        try {
            Files.move(tmp.toPath(), file.toPath(), StandardCopyOption.REPLACE_EXISTING, StandardCopyOption.ATOMIC_MOVE)
        } catch (e: AtomicMoveNotSupportedException) {
            Files.move(tmp.toPath(), file.toPath(), StandardCopyOption.REPLACE_EXISTING)
        }
    }
}

fun BufferKey.storageId(): String = "${serverId}__${name}"