package com.example.privateamazon

import android.net.http.SslError
import android.os.Bundle
import android.view.View
import android.webkit.CookieManager
import android.webkit.SslErrorHandler
import android.webkit.WebResourceRequest
import android.webkit.WebResourceResponse
import android.webkit.WebSettings
import android.webkit.WebStorage
import android.webkit.WebView
import android.webkit.WebViewClient
import androidx.activity.ComponentActivity
import androidx.activity.OnBackPressedCallback
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import androidx.webkit.WebSettingsCompat
import androidx.webkit.WebViewCompat
import androidx.webkit.WebViewFeature
import java.io.ByteArrayInputStream

class MainActivity : ComponentActivity() {

    private lateinit var webView: WebView
    private val blockPatterns = mutableListOf<Regex>()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // 1. Fix Status Bar Overlay (Push app below the clock/battery)
        val mainContainer = findViewById<View>(R.id.main_container)
        ViewCompat.setOnApplyWindowInsetsListener(mainContainer) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }

        webView = findViewById(R.id.webview)

        // 2. Configure WebSettings
        val webSettings: WebSettings = webView.settings
        webSettings.javaScriptEnabled = true
        webSettings.domStorageEnabled = true
        webSettings.cacheMode = WebSettings.LOAD_DEFAULT
        webSettings.mixedContentMode = WebSettings.MIXED_CONTENT_NEVER_ALLOW

        // Privacy Hardening
        webSettings.allowFileAccess = false
        webSettings.allowContentAccess = false
        webSettings.setGeolocationEnabled(false)
        webSettings.userAgentString = "Mozilla/5.0 (Linux; Android 10; Mobile) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114 Mobile Safari/537.36"

        // 3. Feature Checks (Safe Browsing & Dark Mode)
        if (WebViewFeature.isFeatureSupported(WebViewFeature.START_SAFE_BROWSING)) {
            WebViewCompat.startSafeBrowsing(this) { }
        }

        if (WebViewFeature.isFeatureSupported(WebViewFeature.FORCE_DARK)) {
            WebSettingsCompat.setForceDark(webSettings, WebSettingsCompat.FORCE_DARK_ON)
        }

        // 4. --- COOKIE CONFIGURATION (STAY LOGGED IN) ---
        val cookieManager = CookieManager.getInstance()
        cookieManager.setAcceptCookie(true)
        cookieManager.setAcceptThirdPartyCookies(webView, false) // Block trackers, allow Amazon
        // ------------------------------------------------

        // 5. Handle Back Button
        onBackPressedDispatcher.addCallback(this, object : OnBackPressedCallback(true) {
            override fun handleOnBackPressed() {
                if (webView.canGoBack()) webView.goBack() else finish()
            }
        })

        loadFilterList()

        // 6. Set up the WebView Client
        webView.webViewClient = object : WebViewClient() {

            override fun shouldInterceptRequest(view: WebView?, request: WebResourceRequest?): WebResourceResponse? {
                val req = request ?: return null
                val urlStr = req.url.toString().lowercase()

                // Block Trackers from filters.txt
                for (pattern in blockPatterns) {
                    if (pattern.containsMatchIn(urlStr)) {
                        return WebResourceResponse("text/plain", "utf-8", ByteArrayInputStream("".toByteArray()))
                    }
                }

                // Block cleartext (Force HTTPS)
                if (urlStr.startsWith("http://")) {
                    return WebResourceResponse("text/plain", "utf-8", ByteArrayInputStream("".toByteArray()))
                }

                return null
            }

            override fun onReceivedSslError(view: WebView?, handler: SslErrorHandler?, error: SslError?) {
                handler?.cancel() // Security: Don't allow bad SSL
            }

            override fun onPageFinished(view: WebView?, url: String?) {
                super.onPageFinished(view, url)
                // Save cookies to disk immediately after page loads
                CookieManager.getInstance().flush()
                injectPrivacyScript()
            }
        }

        // 7. Load Amazon with a custom header to hide the "App" identity
        val extraHeaders = mapOf("X-Requested-With" to "")
        webView.loadUrl("https://www.amazon.co.uk", extraHeaders)
    }

    private fun loadFilterList() {
        try {
            assets.open("filters.txt").bufferedReader().useLines { lines ->
                lines.map { it.trim() }
                    .filter { it.isNotEmpty() && !it.startsWith("#") }
                    .forEach { rule ->
                        val escaped = rule.replace(".", "\\.").replace("*", ".*")
                        blockPatterns.add(Regex(escaped, RegexOption.IGNORE_CASE))
                    }
            }
        } catch (_: Exception) {}
    }

    private fun injectPrivacyScript() {
        val js = """
            (function() {
              try {
                navigator.sendBeacon = function(){ return true; };
                window.RTCPeerConnection = null;
                window.webkitRTCPeerConnection = null;
                
                const getContext = HTMLCanvasElement.prototype.getContext;
                HTMLCanvasElement.prototype.getContext = function(type) {
                    if (type.includes('webgl')) return null;
                    return getContext.apply(this, arguments);
                };
              } catch(_){}
            })();
        """.trimIndent()
        webView.evaluateJavascript(js, null)
    }

    override fun onPause() {
        super.onPause()
        // Save cookies to disk when app goes to background
        CookieManager.getInstance().flush()
    }
}