/**
 * Millisa AI Client for Android (Kotlin)
 * ─────────────────────────────────────────────────────────────────────────────
 * Dependency: com.squareup.okhttp3:okhttp:4.12.0
 *             org.jetbrains.kotlinx:kotlinx-coroutines-android:1.8.0
 *             com.google.code.gson:gson:2.10.1
 */

package com.example.millisa

import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.withContext
import okhttp3.MediaType.Companion.toMediaType
import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.RequestBody.Companion.toRequestBody
import org.json.JSONArray
import org.json.JSONObject
import java.io.IOException
import java.util.concurrent.TimeUnit

class MillisaClient(
    private val apiKey: String,
    private val baseUrl: String = "https://millisa.codly.in/api/v1"
) {
    private val client = OkHttpClient.Builder()
        .connectTimeout(30, TimeUnit.SECONDS)
        .readTimeout(60, TimeUnit.SECONDS)
        .build()

    private val jsonMediaType = "application/json; charset=utf-8".toMediaType()

    /**
     * Send a query to Millisa AI Agent
     *
     * @param prompt The message or question for Millisa
     * @param model Model to use (e.g., "millisa-auto", "millisa-gemini-flash", "millisa-gpt-4o-mini")
     * @return The text response from Millisa
     */
    suspend fun queryAgent(prompt: String, model: String = "millisa-auto"): Result<String> {
        return withContext(Dispatchers.IO) {
            try {
                val payload = JSONObject().apply {
                    put("prompt", prompt)
                    put("model", model)
                }

                val request = Request.Builder()
                    .url("$baseUrl/agent/query")
                    .addHeader("Authorization", "Bearer $apiKey")
                    .addHeader("Content-Type", "application/json")
                    .post(payload.toString().toRequestBody(jsonMediaType))
                    .build()

                val response = client.newCall(request).execute()
                val responseBody = response.body?.string() ?: ""

                if (!response.isSuccessful) {
                    val errorMsg = try {
                        JSONObject(responseBody).getJSONObject("error").getString("message")
                    } catch (e: Exception) {
                        "HTTP ${response.code}: $responseBody"
                    }
                    return@withContext Result.failure(IOException(errorMsg))
                }

                val json = JSONObject(responseBody)
                val reply = json.optString("response", "No response received.")
                Result.success(reply)

            } catch (e: Exception) {
                Result.failure(e)
            }
        }
    }

    /**
     * Send OpenAI-compatible multi-turn Chat Completion
     */
    suspend fun chatCompletion(
        messages: List<Pair<String, String>>, // role to content
        model: String = "millisa-auto"
    ): Result<String> {
        return withContext(Dispatchers.IO) {
            try {
                val jsonMessages = JSONArray()
                for ((role, content) in messages) {
                    jsonMessages.put(JSONObject().apply {
                        put("role", role)
                        put("content", content)
                    })
                }

                val payload = JSONObject().apply {
                    put("model", model)
                    put("messages", jsonMessages)
                }

                val request = Request.Builder()
                    .url("$baseUrl/chat/completions")
                    .addHeader("Authorization", "Bearer $apiKey")
                    .addHeader("Content-Type", "application/json")
                    .post(payload.toString().toRequestBody(jsonMediaType))
                    .build()

                val response = client.newCall(request).execute()
                val body = response.body?.string() ?: ""

                if (!response.isSuccessful) {
                    return@withContext Result.failure(IOException("Error ${response.code}: $body"))
                }

                val reply = JSONObject(body)
                    .getJSONArray("choices")
                    .getJSONObject(0)
                    .getJSONObject("message")
                    .getString("content")

                Result.success(reply)
            } catch (e: Exception) {
                Result.failure(e)
            }
        }
    }
}

// ─────────────────────────────────────────────────────────────────────────────
// Usage Example in Android ViewModel / Activity / Jetpack Compose:
// ─────────────────────────────────────────────────────────────────────────────
/*
val millisa = MillisaClient(apiKey = "mls_live_YOUR_MILLISA_API_KEY")

lifecycleScope.launch {
    val result = millisa.queryAgent("Hello Millisa, how do I build a modern Android UI?")
    result.onSuccess { reply ->
        println("Millisa replied: $reply")
    }.onFailure { error ->
        println("Error connecting to Millisa: ${error.message}")
    }
}
*/