bricks-mp/shared/src/commonMain/kotlin/com/bricks/mp/sage/SageClient.kt

package com.bricks.mp.sage

import com.bricks.mp.core.BricksParser
import com.bricks.mp.core.BricksWidget
import io.ktor.client.*
import io.ktor.client.engine.cio.*
import io.ktor.client.plugins.cookies.*
import io.ktor.client.request.*
import io.ktor.client.statement.*
import io.ktor.http.*
import kotlinx.coroutines.sync.Mutex
import kotlinx.coroutines.sync.withLock
import kotlinx.serialization.json.*

/**
 * Sage 客户端 - 处理登录、Session 管理和 UI 加载
 * 
 * Sage 使用 Cookie Session 认证：
 * 1. POST /rbac/user/userpassword_login.dspy 登录获取 session cookie
 * 2. 后续请求自动携带 cookie
 * 3. GET /xxx.ui 获取 JSON 格式的 UI 描述
 */
class SageClient {

    companion object {
        const val DEFAULT_BASE_URL = "https://ai.atvoe.com"
    }

    private val cookieStorage = AcceptAllCookiesStorage()

    private val client = HttpClient(CIO) {
        install(HttpCookies) {
            storage = cookieStorage
        }
        expectSuccess = false
        followRedirects = true
    }

    var baseUrl: String = DEFAULT_BASE_URL

    // 登录状态
    private val _isLoggedIn = kotlinx.coroutines.flow.MutableStateFlow(false)
    val isLoggedIn: kotlinx.coroutines.flow.StateFlow<Boolean> = _isLoggedIn

    private val _loginError = kotlinx.coroutines.flow.MutableStateFlow<String?>(null)
    val loginError: kotlinx.coroutines.flow.StateFlow<String?> = _loginError

    private val mutex = Mutex()

    /**
     * 登录 Sage 服务器
     * POST /rbac/user/userpassword_login.dspy
     */
    suspend fun login(username: String, password: String): Boolean = mutex.withLock {
        _loginError.value = null
        try {
            val url = "$baseUrl/rbac/user/userpassword_login.dspy"
            val formBody = "username=${encodeURLParameter(username)}&passwd=${encodeURLParameter(password)}"

            val response = client.post(url) {
                contentType(ContentType.Application.FormUrlEncoded)
                setBody(formBody)
            }

            val body = response.bodyAsText()
            println("[Sage] Login response status: ${response.status}")
            println("[Sage] Login response body: ${body.take(200)}")

            // Sage 返回 UiMessage 格式: {"widgettype": "Message", "options": {...}}
            // 或者返回错误: {"widgettype": "Error", "options": {...}}
            val json = try {
                Json.parseToJsonElement(body).jsonObject
            } catch (e: Exception) {
                _loginError.value = "登录响应格式错误: ${e.message}"
                return@withLock false
            }

            val widgetType = json["widgettype"]?.jsonPrimitive?.content

            if (widgetType == "Message" || widgetType == "UiMessage") {
                // 检查是否有 session cookie
                val cookies = cookieStorage.get(URLBuilder(baseUrl).build())
                if (cookies.isNotEmpty()) {
                    println("[Sage] Login successful, got ${cookies.size} cookies")
                    _isLoggedIn.value = true
                    true
                } else {
                    // 即使没有 cookie，如果服务器返回成功也算登录成功
                    // 有些部署可能使用 token 而非 cookie
                    println("[Sage] Login successful (no cookies)")
                    _isLoggedIn.value = true
                    true
                }
            } else {
                // 错误消息
                val options = json["options"]?.jsonObject ?: JsonObject(emptyMap())
                val message = options["message"]?.jsonPrimitive?.content
                    ?: options["text"]?.jsonPrimitive?.content
                    ?: body.take(100)
                _loginError.value = message
                println("[Sage] Login failed: $message")
                false
            }
        } catch (e: Exception) {
            _loginError.value = "登录失败: ${e.message}"
            println("[Sage] Login error: ${e.message}")
            false
        }
    }

    /**
     * 获取 .ui 文件（JSON 格式的 UI 描述）
     */
    suspend fun fetchUi(path: String): Result<BricksWidget> = mutex.withLock {
        try {
            val url = if (path.startsWith("http")) path else "$baseUrl/${path.trimStart('/')}"
            println("[Sage] Fetching UI: $url")

            val response = client.get(url)
            val body = response.bodyAsText()

            if (!response.status.isSuccess()) {
                return@withLock Result.failure(Exception("HTTP ${response.status.value}: ${body.take(200)}"))
            }

            val widget = BricksParser.parse(body)
            Result.success(widget)
        } catch (e: Exception) {
            println("[Sage] Fetch UI error: ${e.message}")
            Result.failure(e)
        }
    }

    /**
     * 获取 .dspy API 返回的 JSON
     */
    suspend fun fetchApi(
        path: String,
        params: Map<String, String> = emptyMap(),
        method: String = "GET",
        formBody: String = "",
        jsonBody: JsonObject? = null
    ): Result<JsonObject> = mutex.withLock {
        try {
            val url = if (path.startsWith("http")) path else "$baseUrl/${path.trimStart('/')}"

            val response = when (method.uppercase()) {
                "POST" -> client.post(url) {
                    url {
                        params.forEach { (k, v) -> parameters.append(k, v) }
                    }
                    when {
                        jsonBody != null -> {
                            contentType(ContentType.Application.Json)
                            setBody(jsonBody)
                        }
                        formBody.isNotEmpty() -> {
                            contentType(ContentType.Application.FormUrlEncoded)
                            setBody(formBody)
                        }
                    }
                }
                else -> client.get(url) {
                    url {
                        params.forEach { (k, v) -> parameters.append(k, v) }
                    }
                }
            }

            val body = response.bodyAsText()
            val json = Json.parseToJsonElement(body).jsonObject
            Result.success(json)
        } catch (e: Exception) {
            Result.failure(e)
        }
    }

    /**
     * 获取文本内容
     */
    suspend fun fetchText(path: String): Result<String> = mutex.withLock {
        try {
            val url = if (path.startsWith("http")) path else "$baseUrl/${path.trimStart('/')}"
            val response = client.get(url)
            Result.success(response.bodyAsText())
        } catch (e: Exception) {
            Result.failure(e)
        }
    }

    /**
     * 退出登录
     */
    suspend fun logout() = mutex.withLock {
        try {
            _isLoggedIn.value = false
            println("[Sage] Logged out")
        } catch (e: Exception) {
            println("[Sage] Logout error: ${e.message}")
        }
    }

    /**
     * 关闭客户端
     */
    fun close() {
        client.close()
    }
}