package editor

import (
	"testing"

	"glint/internal/theme"

	"github.com/charmbracelet/lipgloss"
)

// styleOf returns the foreground color of the span covering the first occurrence
// of sub within the line's spans, or "" if not found.
func styleOf(spans []Span, sub string) lipgloss.Color {
	for _, sp := range spans {
		if sp.Text == sub {
			return lipgloss.Color(sp.Style.GetForeground().(lipgloss.Color))
		}
	}
	return lipgloss.Color("")
}

func TestCodeScannerColorsStrings(t *testing.T) {
	th := theme.FlexokiDark()
	out := ScanCode([]string{`x := "hello"`}, "main.go", th)
	if got := styleOf(out[0], `"hello"`); got != th.Code {
		t.Errorf("string color = %q, want Code %q (spans: %+v)", got, th.Code, out[0])
	}
}

func TestCodeScannerColorsComments(t *testing.T) {
	th := theme.FlexokiDark()
	out := ScanCode([]string{"// a note"}, "main.go", th)
	// The whole comment line should be Comment-colored.
	for _, sp := range out[0] {
		if sp.Style.GetForeground() != th.Comment {
			t.Errorf("comment span %q color = %v, want Comment %v", sp.Text, sp.Style.GetForeground(), th.Comment)
		}
	}
}

func TestCodeScannerColorsNumbers(t *testing.T) {
	th := theme.FlexokiDark()
	out := ScanCode([]string{"x := 42"}, "main.go", th)
	if got := styleOf(out[0], "42"); got != th.Accent {
		t.Errorf("number color = %q, want Accent %q (spans: %+v)", got, th.Accent, out[0])
	}
}

func TestCodeScannerIdentifiersStayBase(t *testing.T) {
	th := theme.FlexokiDark()
	out := ScanCode([]string{"foo := bar"}, "main.go", th)
	if got := styleOf(out[0], "foo"); got != th.Text {
		t.Errorf("identifier color = %q, want base Text %q", got, th.Text)
	}
}

func TestCodeScannerInvariant(t *testing.T) {
	th := theme.FlexokiDark()
	lines := []string{
		`package main`,
		``,
		`func main() {`,
		`	x := "hi" // greet`,
		`	_ = x + 1`,
		`}`,
	}
	out := ScanCode(lines, "main.go", th)
	if len(out) != len(lines) {
		t.Fatalf("got %d lines of spans, want %d", len(out), len(lines))
	}
	for i, raw := range lines {
		if got := spanText(out[i]); got != raw {
			t.Errorf("line %d: span text %q != raw %q", i, got, raw)
		}
	}
}

func TestCodeScannerMultilineComment(t *testing.T) {
	th := theme.FlexokiDark()
	lines := []string{"/* first", "second */"}
	out := ScanCode(lines, "main.go", th)
	for i := range lines {
		if len(out[i]) == 0 {
			t.Fatalf("line %d empty", i)
		}
		for _, sp := range out[i] {
			if sp.Style.GetForeground() != th.Comment {
				t.Errorf("line %d span %q color = %v, want Comment", i, sp.Text, sp.Style.GetForeground())
			}
		}
	}
}

func TestBuildVisualUsesCodeScannerForCode(t *testing.T) {
	e := New()
	e.SetContent([]byte(`x := "hi"`))
	e.SetLanguage("main.go")
	var found bool
	for _, vr := range e.buildVisual() {
		if c := styleOf(vr.spans, `"hi"`); c == e.theme.Code {
			found = true
		}
	}
	if !found {
		t.Error("code file: string not colored via buildVisual")
	}
}

func TestBuildVisualKeepsMarkdownForMd(t *testing.T) {
	e := New()
	e.SetContent([]byte("# Title"))
	e.SetLanguage("notes.md")
	var found bool
	for _, vr := range e.buildVisual() {
		if c := styleOf(vr.spans, "Title"); c == e.theme.Heading {
			found = true
		}
	}
	if !found {
		t.Error("markdown file: heading not colored via buildVisual (wrong scanner?)")
	}
}

func TestSetLanguageRoutesScanner(t *testing.T) {
	e := New()
	e.SetLanguage("main.go")
	if e.codeFile == "" {
		t.Error("SetLanguage(main.go) should enable the code scanner")
	}
	e.SetLanguage("notes.md")
	if e.codeFile != "" {
		t.Errorf("SetLanguage(notes.md) should keep markdown scanner, got codeFile=%q", e.codeFile)
	}
	e.SetLanguage("plain.txt")
	if e.codeFile != "" {
		t.Errorf("SetLanguage(plain.txt) should keep markdown scanner, got codeFile=%q", e.codeFile)
	}
	e.SetLanguage("README")
	if e.codeFile != "" {
		t.Errorf("SetLanguage(README) (no ext) should keep markdown scanner, got codeFile=%q", e.codeFile)
	}
}