package org.terst.feedreader.ui

import android.content.Context
import android.content.Intent
import android.net.Uri
import android.view.View
import android.webkit.WebResourceRequest
import android.webkit.WebView
import android.webkit.WebViewClient
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.material3.AlertDialog
import androidx.compose.material3.Text
import androidx.compose.material3.TextButton
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.text.style.TextOverflow

private fun isYouTubeWatchUrl(uri: Uri): Boolean {
    val host = uri.host?.lowercase() ?: return false
    return host == "youtu.be" || host.endsWith(".youtube.com") || host == "youtube.com"
}

/**
 * Shared factory for the read-only, dark-themed article WebView used by both the
 * per-article ReaderScreen and LinkReaderScreen (for links tapped inside an article).
 * JS is always off -- extracted/feed HTML never needs it, and this keeps articles
 * from running arbitrary scripts. Link taps are intercepted rather than left to
 * WebView's default behavior (handing off to the system browser) so following a
 * link stays inside the app's own reader/extraction pipeline -- except a YouTube
 * watch link (what ReaderExtractor turns an embedded video into a thumbnail link
 * to), which goes straight to the YouTube app/browser instead: there's nothing for
 * our own Readability-based reader pipeline to usefully extract from a video page.
 *
 * onLongPressLink fires for a long-press on a link (a plain one, or an image
 * wrapped in one, e.g. the YouTube thumbnail) with the target URL, instead of
 * WebView's own default long-press behavior (a native "open/copy link" popup) --
 * callers show their own save/share/open action menu instead.
 */
fun newReaderWebView(context: Context, onOpenLink: (String) -> Unit, onLongPressLink: (String) -> Unit = {}): WebView =
    WebView(context).apply {
        settings.javaScriptEnabled = false
        overScrollMode = View.OVER_SCROLL_NEVER
        isVerticalScrollBarEnabled = false
        isHorizontalScrollBarEnabled = false
        webViewClient = object : WebViewClient() {
            override fun shouldOverrideUrlLoading(view: WebView, request: WebResourceRequest): Boolean {
                val url = request.url
                if (isYouTubeWatchUrl(url)) {
                    context.startActivity(Intent(Intent.ACTION_VIEW, url))
                } else {
                    onOpenLink(url.toString())
                }
                return true
            }
        }
        setOnLongClickListener {
            val result = hitTestResult
            val url = when (result.type) {
                WebView.HitTestResult.SRC_ANCHOR_TYPE, WebView.HitTestResult.SRC_IMAGE_ANCHOR_TYPE -> result.extra
                else -> null
            }
            if (url != null) {
                onLongPressLink(url)
                true
            } else {
                false
            }
        }
    }

@Composable
fun LinkActionsDialog(
    url: String,
    onDismiss: () -> Unit,
    onOpenInBrowser: () -> Unit,
    onShare: () -> Unit,
    onSaveToStash: () -> Unit,
    onSaveForLater: () -> Unit
) {
    AlertDialog(
        onDismissRequest = onDismiss,
        title = { Text(url, maxLines = 2, overflow = TextOverflow.Ellipsis) },
        text = {
            Column {
                TextButton(onClick = { onDismiss(); onOpenInBrowser() }, modifier = Modifier.fillMaxWidth()) {
                    Text("Open in browser")
                }
                TextButton(onClick = { onDismiss(); onShare() }, modifier = Modifier.fillMaxWidth()) {
                    Text("Share")
                }
                TextButton(onClick = { onDismiss(); onSaveToStash() }, modifier = Modifier.fillMaxWidth()) {
                    Text("Save to Stash")
                }
                TextButton(onClick = { onDismiss(); onSaveForLater() }, modifier = Modifier.fillMaxWidth()) {
                    Text("Save for later")
                }
            }
        },
        confirmButton = {},
        dismissButton = { TextButton(onClick = onDismiss) { Text("Cancel") } }
    )
}

private fun escapeHtml(text: String): String = text
    .replace("&", "&")
    .replace("<", "&lt;")
    .replace(">", "&gt;")
    .replace("\"", "&quot;")
    .replace("'", "&#39;")

// Hardcoded dark palette, not @media (prefers-color-scheme) -- the app itself always
// forces dark colorScheme() regardless of system setting (see MainActivity), so reader
// content should match rather than following a system light/dark the app itself ignores.
//
// title is rendered here, as a real heading at the top of the content, rather than relying
// on whatever heading Readability happened to keep in bodyContent (increasingly nothing --
// see ReaderExtractor's <header> stripping) or on the top app bar's title, which truncates
// to one line and was the only place a long title showed up before this.
fun wrapReaderHtml(bodyContent: String, title: String? = null): String = """
    <html><head><meta name="viewport" content="width=device-width, initial-scale=1">
    <style>
    body { font-family: sans-serif; font-size: 18px; line-height: 1.5; padding: 16px;
           background-color: #121212; color: #e1e1e1; }
    h1.article-title { font-size: 1.5em; line-height: 1.3; margin: 0 0 0.6em 0; }
    a { color: #8ab4f8; }
    img { max-width: 100%; height: auto; }
    svg { max-width: 100%; }
    /* A decorative icon (section badge, share glyph, etc.) that slipped through
       extraction relies on the source site's own stylesheet for its real display
       size (commonly Tailwind classes like "h-5 w-5") -- which we don't load here.
       An <svg> with no explicit width/height falls back to the browser's default
       (much larger than any inline icon is meant to be, confirmed live: Ars
       Technica's per-article section-badge icon rendering "giant"). One WITH
       explicit width/height was deliberately sized by the page itself, so leave
       those alone -- just cap the ones that would otherwise size themselves. */
    svg:not([width]):not([height]) { max-width: 32px; max-height: 32px; }
    </style></head>
    <body>${if (!title.isNullOrBlank()) "<h1 class=\"article-title\">${escapeHtml(title)}</h1>" else ""}$bodyContent</body></html>
""".trimIndent()