package com.harmness.toolwindow

import com.intellij.openapi.Disposable
import com.intellij.openapi.diagnostic.Logger
import java.lang.reflect.InvocationTargetException
import java.util.function.Function
import javax.swing.JComponent

/**
 * JCEF JS↔Java 桥的反射封装。
 *
 * 负责两件事：
 *  1. 通过反射创建 JBCefJSQuery 并注册 handler（把网页发来的字符串请求转发给 [onRequest]）
 *  2. 通过反射调用 JBCefJSQuery.inject() 生成注入到页面的 JS 代码
 *
 * 与 [EmbeddedBrowser] 一样，编译期零 JCEF 依赖。类缺失/调用失败时
 * 仅返回 null / 空串，不影响浏览器主体功能。
 */
class EmbeddedJsBridge private constructor(
    private val queryInstance: Any,
    private val onRequest: (String) -> Any?
) {

    /**
     * 返回可注入到页面 JS 的代码片段（调用插件 handler），
     * 失败返回空串。
     */
    fun injectJs(): String = try {
        val m = queryInstance.javaClass.getMethod(
            "inject", String::class.java, String::class.java, String::class.java
        )
        (m.invoke(queryInstance, "payload.query",
            "function(response){ if (payload.callbacks && payload.callbacks.onSuccess) payload.callbacks.onSuccess(response); }",
            "function(code,msg){ if (payload.callbacks && payload.callbacks.onFailure) payload.callbacks.onFailure(code,msg); }"
        ) as? String) ?: ""
    } catch (t: Throwable) {
        log.warn("injectJs failed", t)
        ""
    }

    fun dispose() {
        try {
            queryInstance.javaClass.getMethod("dispose").invoke(queryInstance)
        } catch (t: Throwable) {
            log.warn("bridge dispose failed", t)
        }
    }

    companion object {
        private val log = Logger.getInstance(EmbeddedJsBridge::class.java)

        /**
         * 为已创建的 [browser] 建立 JS 桥。
         * @return 成功返回桥对象；失败返回 null（浏览器仍可用，仅网页无法调用插件 API）
         */
        fun create(browser: EmbeddedBrowser, onRequest: (String) -> Any?): EmbeddedJsBridge? {
            try {
                val queryClass = Class.forName("com.intellij.ui.jcef.JBCefJSQuery")
                // create(JBCefBrowserBase) — 用可赋值参数类型查找
                val browserInst = browser.instance
                val createMethod = queryClass.methods.firstOrNull { m ->
                    m.name == "create" && m.parameterCount == 1 &&
                        m.parameterTypes[0].isAssignableFrom(browserInst.javaClass)
                } ?: return null
                val queryInstance = createMethod.invoke(null, browserInst)

                // addHandler(java.util.function.Function<String, Response>)
                val handlerFn = Function<String, Any?> { req -> onRequest(req ?: "") }
                val addMethod = queryClass.methods.firstOrNull { m ->
                    m.name == "addHandler" && m.parameterCount == 1 &&
                        m.parameterTypes[0] == Function::class.java
                } ?: return null
                addMethod.invoke(queryInstance, handlerFn)

                return EmbeddedJsBridge(queryInstance, onRequest)
            } catch (t: Throwable) {
                val real = when (t) {
                    is InvocationTargetException -> t.targetException ?: t
                    else -> t
                }
                log.warn("EmbeddedJsBridge.create failed: ${real.javaClass.simpleName}: ${real.message}", real)
                return null
            }
        }
    }
}