package editor

import (
	"strings"
	"testing"

	tea "github.com/charmbracelet/bubbletea"
)

func cacheDoc() *Editor {
	e := New()
	var b strings.Builder
	for i := 0; i < 200; i++ {
		b.WriteString("Some **prose** line with a [link](http://x) and `code` here.\n")
	}
	e.SetContent([]byte(b.String()))
	e.SetSize(80, 24)
	return e
}

// Scrolling and rendering must not re-scan the whole document: the visual model
// depends only on content/width/theme/spell, none of which a scroll changes.
func TestScrollReusesVisualCache(t *testing.T) {
	e := cacheDoc()
	e.buildCount = 0
	for i := 0; i < 10; i++ {
		e.ScrollBy(1)
		_ = e.View()
	}
	if e.buildCount > 1 {
		t.Errorf("scroll+view rebuilt visual %d times, want <= 1", e.buildCount)
	}
}

// An edit must invalidate the cache so the next render reflects new content.
func TestEditInvalidatesCache(t *testing.T) {
	e := cacheDoc()
	_ = e.View() // prime cache
	e.SetContent([]byte("brand new content\n"))
	out := e.View()
	if !strings.Contains(out, "brand new content") {
		t.Errorf("View after SetContent did not reflect new content:\n%s", out)
	}
}

// A bracketed-paste KeyMsg delivers the whole paste as one multi-rune
// tea.KeyMsg. Each rune it inserts must not rebuild the visual cache off a
// half-inserted buffer (that stale cache never gets invalidated again, so the
// screen would freeze on the first pasted character even though e.Lines has
// the rest of the text).
func TestPasteKeyMsgReflectsFullTextImmediately(t *testing.T) {
	e := New()
	e.SetContent([]byte(""))
	e.SetSize(80, 24)
	e.HandleKey(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("hello world"), Paste: true})

	if e.Lines[0] != "hello world" {
		t.Fatalf("Lines[0] = %q, want %q", e.Lines[0], "hello world")
	}
	if out := e.View(); !strings.Contains(out, "hello world") {
		t.Errorf("View after paste did not reflect full pasted text, only:\n%s", out)
	}
}

// A multi-line paste's embedded newlines must split into separate logical
// lines, not sit as literal '\n' runes inside one Lines[] entry.
func TestPasteKeyMsgSplitsEmbeddedNewlines(t *testing.T) {
	e := New()
	e.SetContent([]byte(""))
	e.SetSize(80, 24)
	e.HandleKey(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("line1\nline2"), Paste: true})

	want := []string{"line1", "line2"}
	if len(e.Lines) != len(want) || e.Lines[0] != want[0] || e.Lines[1] != want[1] {
		t.Fatalf("Lines = %#v, want %#v", e.Lines, want)
	}
}

// InsertText (the explicit Ctrl+V clipboard-paste path) shares the same bulk
// insert and must be equally immune to the stale-cache and embedded-newline
// bugs.
func TestInsertTextReflectsFullTextImmediately(t *testing.T) {
	e := New()
	e.SetContent([]byte(""))
	e.SetSize(80, 24)
	e.InsertText("line1\nline2")

	if len(e.Lines) != 2 || e.Lines[0] != "line1" || e.Lines[1] != "line2" {
		t.Fatalf("Lines = %#v, want [line1 line2]", e.Lines)
	}
	if out := e.View(); !strings.Contains(out, "line1") || !strings.Contains(out, "line2") {
		t.Errorf("View after InsertText did not reflect full text:\n%s", out)
	}
}