package com.estateunified.panel

import com.google.gson.Gson
import com.google.gson.JsonArray
import com.google.gson.JsonObject
import com.google.gson.JsonParser
import java.nio.charset.StandardCharsets
import java.nio.file.Files
import java.nio.file.Path
import java.util.UUID

internal class UserListingsStore(
    private val gson: Gson,
    private val file: Path,
) {
    private val lock = Any()

    fun absolutePath(): String = file.toAbsolutePath().normalize().toString()

    fun readAll(): List<JsonObject> =
        synchronized(lock) {
            if (!Files.isRegularFile(file)) return emptyList()
            val text = Files.readString(file, StandardCharsets.UTF_8)
            if (text.isBlank()) return emptyList()
            return try {
                val arr = JsonParser.parseString(text).asJsonArray
                arr.mapNotNull { if (it.isJsonObject) it.asJsonObject else null }
            } catch (_: Exception) {
                emptyList()
            }
        }

    fun add(payload: JsonObject): JsonObject {
        synchronized(lock) {
            val list = readAll().toMutableList()
            val id =
                payload.getAsJsonPrimitive("id")?.asString?.trim().takeUnless { it.isNullOrBlank() }
                    ?: "owner-${UUID.randomUUID()}"
            payload.addProperty("id", id)
            list.removeAll { it.getAsJsonPrimitive("id").asString == id }
            list.add(0, payload)
            persist(list)
            return payload
        }
    }

    fun delete(id: String): Boolean {
        if (!id.startsWith("owner-")) return false
        synchronized(lock) {
            val list = readAll().toMutableList()
            val removed = list.removeIf { it.getAsJsonPrimitive("id")?.asString == id }
            if (removed) persist(list)
            return removed
        }
    }

    private fun persist(rows: List<JsonObject>) {
        val parent = file.toAbsolutePath().parent
        Files.createDirectories(parent)
        val arr = JsonArray()
        rows.forEach { arr.add(it) }
        Files.writeString(file, gson.toJson(arr), StandardCharsets.UTF_8)
    }
}