package farm.hobbs.clippyauto.matrix

import io.ktor.client.*
import io.ktor.client.call.*
import io.ktor.client.engine.okhttp.*
import io.ktor.client.plugins.contentnegotiation.*
import io.ktor.client.request.*
import io.ktor.http.*
import io.ktor.serialization.kotlinx.json.*
import kotlinx.serialization.json.*
import java.util.UUID

/**
 * Lightweight Matrix REST API client.
 * No E2EE — designed for private homeserver use.
 *
 * Handles: login, message send, long-poll sync (fallback to FCM).
 */
class MatrixRestClient(
    private val homeserverUrl: String
) {
    private val httpClient = HttpClient(OkHttp) {
        install(ContentNegotiation) {
            json(Json { ignoreUnknownKeys = true })
        }
    }

    var accessToken: String? = null
        private set
    private var syncToken: String? = null

    /**
     * Login with username/password, store access token.
     */
    suspend fun login(user: String, password: String): Boolean {
        return try {
            val response = httpClient.post("$homeserverUrl/_matrix/client/v3/login") {
                contentType(ContentType.Application.Json)
                setBody(buildJsonObject {
                    put("type", "m.login.password")
                    put("user", user)
                    put("password", password)
                    putJsonObject("identifier") {
                        put("type", "m.id.user")
                        put("user", user)
                    }
                })
            }
            val body = response.body<JsonObject>()
            accessToken = body["access_token"]?.jsonPrimitive?.content
            accessToken != null
        } catch (e: Exception) {
            false
        }
    }

    /**
     * Login with existing access token (from Keystore).
     */
    fun loginWithToken(token: String) {
        accessToken = token
    }

    /**
     * Send a text message to a room with optional custom fields for session tracking.
     */
    suspend fun sendMessage(
        roomId: String,
        body: String,
        source: String = "voice",
        sessionId: String? = null
    ): Boolean {
        val token = accessToken ?: return false
        val txnId = UUID.randomUUID().toString()
        return try {
            httpClient.put("$homeserverUrl/_matrix/client/v3/rooms/$roomId/send/m.room.message/$txnId") {
                bearerAuth(token)
                contentType(ContentType.Application.Json)
                setBody(buildJsonObject {
                    put("msgtype", "m.text")
                    put("body", body)
                    put("farm.hobbs.clippy.source", source)
                    sessionId?.let { put("farm.hobbs.clippy.session_id", it) }
                })
            }
            true
        } catch (e: Exception) {
            false
        }
    }

    /**
     * Send a session signal (start, end, resume).
     */
    suspend fun sendSessionSignal(roomId: String, signal: String, sessionId: String): Boolean {
        val token = accessToken ?: return false
        val txnId = UUID.randomUUID().toString()
        val signalBody = when (signal) {
            "session_start" -> "[ClippyAuto session started — commute mode, voice-first]"
            "session_resume" -> "[ClippyAuto session resumed]"
            "session_end" -> "[ClippyAuto session ended]"
            else -> "[ClippyAuto signal: $signal]"
        }
        return try {
            httpClient.put("$homeserverUrl/_matrix/client/v3/rooms/$roomId/send/m.room.message/$txnId") {
                bearerAuth(token)
                contentType(ContentType.Application.Json)
                setBody(buildJsonObject {
                    put("msgtype", "m.text")
                    put("body", signalBody)
                    put("farm.hobbs.clippy.signal", signal)
                    put("farm.hobbs.clippy.session_id", sessionId)
                })
            }
            true
        } catch (e: Exception) {
            false
        }
    }

    /**
     * Long-poll sync — fallback when FCM doesn't deliver.
     * Returns list of messages from the target room since last sync.
     */
    suspend fun sync(
        roomId: String,
        timeoutMs: Int = 30000
    ): List<MatrixMessage> {
        val token = accessToken ?: return emptyList()
        return try {
            val url = buildString {
                append("$homeserverUrl/_matrix/client/v3/sync?timeout=$timeoutMs")
                syncToken?.let { append("&since=$it") }
            }
            val response = httpClient.get(url) { bearerAuth(token) }
            val body = response.body<JsonObject>()
            syncToken = body["next_batch"]?.jsonPrimitive?.content

            val rooms = body["rooms"]?.jsonObject
                ?.get("join")?.jsonObject
                ?.get(roomId)?.jsonObject
            val timeline = rooms?.get("timeline")?.jsonObject
                ?.get("events")?.jsonArray ?: return emptyList()

            timeline.mapNotNull { event ->
                val obj = event.jsonObject
                val type = obj["type"]?.jsonPrimitive?.content
                if (type != "m.room.message") return@mapNotNull null

                val content = obj["content"]?.jsonObject ?: return@mapNotNull null
                val sender = obj["sender"]?.jsonPrimitive?.content ?: return@mapNotNull null
                val msgBody = content["body"]?.jsonPrimitive?.content ?: return@mapNotNull null

                MatrixMessage(
                    sender = sender,
                    body = msgBody,
                    source = content["farm.hobbs.clippy.source"]?.jsonPrimitive?.content,
                    sessionId = content["farm.hobbs.clippy.session_id"]?.jsonPrimitive?.content,
                    signal = content["farm.hobbs.clippy.signal"]?.jsonPrimitive?.content
                )
            }
        } catch (e: Exception) {
            emptyList()
        }
    }

    fun shutdown() {
        httpClient.close()
    }
}

data class MatrixMessage(
    val sender: String,
    val body: String,
    val source: String? = null,
    val sessionId: String? = null,
    val signal: String? = null
)