// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
// SPDX-License-Identifier: GPL-3.0-or-later

package app

import (
	"context"
	"fmt"
	"net/http"
	"net/http/httptest"
	"os"
	"os/exec"
	"testing"
	"time"

	"git.stormux.org/storm/cthulhu/internal/atspi"
	"git.stormux.org/storm/cthulhu/internal/review"
)

func TestNativeBrowserInlineReplacementNavigation(t *testing.T) {
	run_native_replacement_navigation(t, false)
}

func TestNativeBrowserGeneratedLinkNavigation(t *testing.T) {
	run_native_replacement_navigation(t, true)
}

func run_native_replacement_navigation(t *testing.T, generated bool) {
	t.Helper()
	if os.Getenv("CTHULHU_NATIVE_BROWSER") != "1" {
		t.Skip("requires private browser session")
	}
	ctx, cancel := context.WithTimeout(context.Background(), 25*time.Second)
	defer cancel()
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if generated {
			fmt.Fprint(w, `<!doctype html><title>Inline replacement regression</title>
<style>
a:link {background-image:linear-gradient(blue,blue);background-size:0% 0.1em;background-position:50% 100%;background-repeat:no-repeat;transition:none;text-decoration:underline}
a:hover {background-size:100% 0.1em;text-decoration:none}
a[href^="http"]::before {content:"↺ ";color:black}
a[href^="http"]:hover {text-underline-offset:0.2em;transition:background-size 0.2s ease-in-out}
</style>
<p>Published <a id="attribution" href="https://example.invalid/source">by <em>Publisher</em> some hours ago</a>. Article continues</p>`)
			return
		}
		fmt.Fprint(w, `<!doctype html><title>Inline replacement regression</title>
<p id="paragraph">Published<br aria-hidden="true">↺ by Publisher<br aria-hidden="true">Article continues</p>
<script>
document.addEventListener('keydown', event => {
  if (event.key !== 'F8') return;
  event.preventDefault();
  const paragraph = document.getElementById('paragraph');
  paragraph.replaceChild(document.createTextNode('↺ by Publisher'), paragraph.childNodes[2]);
});
</script>`)
	}))
	defer server.Close()
	adapter := atspi.New()
	if err := adapter.Start(ctx); err != nil {
		t.Fatal(err)
	}
	defer adapter.Stop(context.Background())
	command := func(args ...string) {
		t.Helper()
		if output, err := exec.CommandContext(ctx, "xdotool", args...).CombinedOutput(); err != nil {
			t.Fatalf("xdotool: %v: %s", err, output)
		}
	}
	command("key", "--clearmodifiers", "ctrl+l")
	command("type", "--clearmodifiers", "--delay", "0", server.URL)
	command("key", "Return")
	var document atspi.ObjectID
	for !document.Valid() {
		select {
		case event := <-adapter.Events():
			if event.Type == atspi.DocumentLoadCompleteEvent && event.Source.Name == "Inline replacement regression" {
				document = event.Source.ID()
			}
		case <-ctx.Done():
			t.Fatal(ctx.Err())
		}
	}
	worker, err := review.NewWorker(adapter, 2*time.Second)
	if err != nil {
		t.Fatal(err)
	}
	if err := worker.Start(ctx); err != nil {
		t.Fatal(err)
	}
	defer worker.Stop(context.Background())
	worker.SyncFocus(document)
	dump_generated_tree := func() {
		if !generated {
			return
		}
		tree, captureErr := adapter.CaptureDocument(ctx, document)
		if captureErr != nil {
			return
		}
		ref, _ := tree.Reference(document)
		doc, _ := tree.Document(ctx, ref)
		for _, node := range doc.Nodes {
			if node.Snapshot.Role == "static" {
				text, err := adapter.ReadDocumentCaret(ctx, node.Reference, 0, atspi.DocumentCaretLine)
				t.Logf("native node %s parent=%s name=%q count=%d text=%+v err=%v", node.Snapshot.Path, node.Parent.Path, node.Snapshot.Name, node.Snapshot.CharacterCount, text, err)
			}
		}
	}
	move := func(command review.DocumentCaretCommand, want string) review.Result {
		t.Helper()
		if err := worker.MoveDocumentCaret(command); err != nil {
			t.Fatal(err)
		}
		select {
		case result := <-worker.Results():
			// Generated text can disappear between a successful virtual move
			// and native placement. A caret error must not undo that move;
			// require the exact text and subsequent navigation/replacement
			// checks rather than requiring the transient native caret to stick.
			if result.Err != nil || result.CaretErr != nil && !generated || !result.Moved || result.DocumentCaretText != want {
				dump_generated_tree()
				t.Fatalf("%s: text=%q want=%q err=%v caret=%v diagnostics=%+v", command,
					result.DocumentCaretText, want, result.Err, result.CaretErr, result.DocumentDiagnostics)
			}
			if generated && result.CaretErr != nil {
				t.Logf("generated native caret: %v; virtual movement succeeded", result.CaretErr)
			}
			return result
		case <-ctx.Done():
			t.Fatal(ctx.Err())
			return review.Result{}
		}
	}
	move(review.CaretNextLine, "Published")
	attribution, after := "↺ by Publisher", "Article continues"
	if generated {
		attribution, after = "↺ by Publisher some hours ago", ". Article continues"
	}
	current := move(review.CaretNextLine, attribution)
	for generation := 0; generation < 4; generation++ {
		old := current.DocumentPosition.Object
		if !generated {
			command("key", "--clearmodifiers", "F8")
		}
		// Require a genuinely replaced native static-text object. Merely
		// changing a label would not exercise recovery of a missing cursor.
		for {
			tree, err := adapter.CaptureDocument(ctx, document)
			if err != nil {
				t.Fatal(err)
			}
			if _, err := tree.Resolve(old); err != nil {
				break
			}
			select {
			case <-adapter.Events():
			case <-ctx.Done():
				t.Fatal("native attribution object was not replaced: ", ctx.Err())
			}
		}
		if generation%2 == 0 {
			move(review.CaretNextLine, after)
			current = move(review.CaretPreviousLine, attribution)
		} else {
			move(review.CaretPreviousLine, "Published")
			current = move(review.CaretNextLine, attribution)
		}
	}
	if err := worker.ReadAll(ctx); err != nil {
		t.Fatal(err)
	}
	select {
	case result := <-worker.Results():
		if result.Err != nil || len(result.ReadAllLines) != 2 {
			t.Fatalf("Read All after replacement: err=%v lines=%d", result.Err, len(result.ReadAllLines))
		}
		for index, want := range []string{attribution, after} {
			if got := result.ReadAllLines[index].Contents[0].Text; got != want {
				dump_generated_tree()
				t.Fatalf("Read All line %d: %q, want %q", index, got, want)
			}
		}
	case <-ctx.Done():
		t.Fatal(ctx.Err())
	}
}