package com.anas4tech.noteable

import android.content.Context
import android.content.Intent
import android.view.View
import android.widget.RemoteViews
import android.widget.RemoteViewsService
import androidx.core.net.toUri

class NotesWidgetRemoteViewsService : RemoteViewsService() {
    override fun onGetViewFactory(intent: Intent): RemoteViewsFactory =
        NotesWidgetRemoteViewsFactory(applicationContext)
}

private class NotesWidgetRemoteViewsFactory(
    private val context: Context
) : RemoteViewsService.RemoteViewsFactory {
    private var notes: List<WidgetNote> = emptyList()

    override fun onCreate() = Unit

    override fun onDataSetChanged() {
        val data = context.getSharedPreferences(PREFERENCES, Context.MODE_PRIVATE)
        val count = data.getInt("notes_count", 0).coerceIn(0, MAX_NOTES)
        notes = (0 until count).map { index ->
            val checkCount = data.getInt("note_${index}_check_count", 0)
                .coerceIn(0, MAX_CHECKLIST_ITEMS)
            val checks = (0 until checkCount).mapNotNull { itemIndex ->
                val itemId = data.getInt("note_${index}_check_${itemIndex}_id", -1)
                if (itemId <= 0) return@mapNotNull null
                WidgetCheckItem(
                    id = itemId,
                    content = data.getString("note_${index}_check_${itemIndex}_content", "") ?: "",
                    completed = data.getBoolean("widget_check_${itemId}_completed", false)
                )
            }
            WidgetNote(
                id = data.getInt("note_${index}_id", -1),
                title = data.getString("note_${index}_title", "") ?: "",
                body = data.getString("note_${index}_body", "") ?: "",
                checklist = checks
            )
        }
    }

    override fun onDestroy() { notes = emptyList() }
    override fun getCount(): Int = notes.size

    override fun getViewAt(position: Int): RemoteViews? {
        val note = notes.getOrNull(position) ?: return null
        val data = context.getSharedPreferences(PREFERENCES, Context.MODE_PRIVATE)
        val palette = WidgetTheme.palette(context, data)
        return RemoteViews(context.packageName, R.layout.noteable_widget_item).apply {
            if (!palette.followsSystem) {
                setTextColor(R.id.widget_note_title, palette.primaryText)
                setTextColor(R.id.widget_note_body, palette.secondaryText)
                CHECKBOX_VIEW_IDS.forEach { setTextColor(it, palette.secondaryText) }
            }
            setTextViewText(R.id.widget_note_title, note.title.ifEmpty { "Untitled note" })
            setViewVisibility(R.id.widget_note_title, if (note.title.isEmpty()) View.GONE else View.VISIBLE)
            setTextViewText(R.id.widget_note_body, note.body)
            setViewVisibility(R.id.widget_note_body, if (note.body.isEmpty()) View.GONE else View.VISIBLE)

            // Fixed checkbox views are more reliable in RemoteViews ListView rows
            // than dynamically adding nested RemoteViews at runtime.
            for (itemIndex in 0 until MAX_CHECKLIST_ITEMS) {
                val viewId = CHECKBOX_VIEW_IDS[itemIndex]
                val item = note.checklist.getOrNull(itemIndex)
                setViewVisibility(viewId, if (item == null) View.GONE else View.VISIBLE)
                if (item != null) {
                    // RemoteViews does not support CheckBox on all supported API levels.
                    // Render the checkbox state as text and keep the row clickable.
                    val checkboxMark = if (item.completed) "☑ " else "☐ "
                    setTextViewText(viewId, checkboxMark + item.content)
                    setOnClickFillInIntent(
                        viewId,
                        Intent().apply {
                            action = WidgetItemClickReceiver.ACTION_TOGGLE_CHECK
                            putExtra(WidgetItemClickReceiver.EXTRA_NOTE_ID, note.id)
                            putExtra(WidgetItemClickReceiver.EXTRA_ITEM_ID, item.id)
                        }
                    )
                }
            }

            setOnClickFillInIntent(
                R.id.widget_note_row,
                Intent().apply {
                    action = WidgetItemClickReceiver.ACTION_OPEN_NOTE
                    putExtra(WidgetItemClickReceiver.EXTRA_NOTE_ID, note.id)
                    this.data = "noteable://open-note/${note.id}?source=list_view".toUri()
                }
            )
        }
    }

    override fun getLoadingView(): RemoteViews? = null
    override fun getViewTypeCount(): Int = 1
    override fun getItemId(position: Int): Long = notes.getOrNull(position)?.id?.toLong() ?: position.toLong()
    override fun hasStableIds(): Boolean = true

    private data class WidgetNote(
        val id: Int, val title: String, val body: String, val checklist: List<WidgetCheckItem>
    )
    private data class WidgetCheckItem(val id: Int, val content: String, val completed: Boolean)

    private companion object {
        const val PREFERENCES = "HomeWidgetPreferences"
        const val MAX_NOTES = 10
        const val MAX_CHECKLIST_ITEMS = 4
        val CHECKBOX_VIEW_IDS = intArrayOf(
            R.id.widget_check_item_0,
            R.id.widget_check_item_1,
            R.id.widget_check_item_2,
            R.id.widget_check_item_3
        )
    }
}