package picker

import (
	"os"
	"path/filepath"
	"sort"
	"strings"
	"testing"
	"time"

	"glint/internal/theme"
)

func TestFuzzyMatchSubsequence(t *testing.T) {
	if _, ok := fuzzyMatch("abc", "axbxc"); !ok {
		t.Error("abc should match axbxc as a subsequence")
	}
	if _, ok := fuzzyMatch("abc", "acb"); ok {
		t.Error("abc should NOT match acb (out of order)")
	}
	if _, ok := fuzzyMatch("", "anything"); !ok {
		t.Error("empty query should match anything")
	}
}

func TestFuzzyMatchCaseInsensitive(t *testing.T) {
	if _, ok := fuzzyMatch("DOC", "my-document"); !ok {
		t.Error("DOC should match my-document case-insensitively")
	}
}

func TestFuzzyMatchContiguousScoresHigher(t *testing.T) {
	tight, ok1 := fuzzyMatch("ab", "abxx")
	loose, ok2 := fuzzyMatch("ab", "axxb")
	if !ok1 || !ok2 {
		t.Fatal("both should match")
	}
	if tight <= loose {
		t.Errorf("contiguous match (%d) should score higher than gapped (%d)", tight, loose)
	}
}

func TestWalkMarkdownSkipsDotDirsAndNonMarkdown(t *testing.T) {
	root := t.TempDir()
	os.WriteFile(filepath.Join(root, "a.md"), nil, 0o644)
	os.WriteFile(filepath.Join(root, "b.txt"), nil, 0o644)
	os.MkdirAll(filepath.Join(root, ".git"), 0o755)
	os.WriteFile(filepath.Join(root, ".git", "c.md"), nil, 0o644)
	os.MkdirAll(filepath.Join(root, "sub"), 0o755)
	os.WriteFile(filepath.Join(root, "sub", "d.md"), nil, 0o644)

	entries, err := walkMarkdown(root)
	if err != nil {
		t.Fatal(err)
	}
	var got []string
	for _, e := range entries {
		got = append(got, e.path)
	}
	sort.Strings(got)
	want := []string{
		filepath.Join(root, "a.md"),
		filepath.Join(root, "sub", "d.md"),
	}
	if len(got) != len(want) {
		t.Fatalf("walkMarkdown = %v, want %v", got, want)
	}
	for i := range want {
		if got[i] != want[i] {
			t.Errorf("got[%d] = %q, want %q", i, got[i], want[i])
		}
	}
}

func TestRankEntriesMtimeDescending(t *testing.T) {
	base := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
	all := []fileEntry{
		{path: "/v/old.md", mod: base},
		{path: "/v/new.md", mod: base.Add(48 * time.Hour)},
		{path: "/v/mid.md", mod: base.Add(24 * time.Hour)},
	}
	got := rankEntries(all, "", "")
	want := []string{"/v/new.md", "/v/mid.md", "/v/old.md"}
	for i := range want {
		if got[i] != want[i] {
			t.Errorf("got[%d] = %q, want %q", i, got[i], want[i])
		}
	}
}

func TestRankEntriesTodayFloatsToTop(t *testing.T) {
	base := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
	all := []fileEntry{
		{path: "/v/new.md", mod: base.Add(48 * time.Hour)},
		{path: "/v/Daily/2026-06-28.md", mod: base}, // oldest, but today
	}
	got := rankEntries(all, "", "/v/Daily/2026-06-28.md")
	if got[0] != "/v/Daily/2026-06-28.md" {
		t.Errorf("today's note should float to top, got %q", got[0])
	}
}

func TestRankEntriesQueryFiltersAndTieBreaksByMtime(t *testing.T) {
	base := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
	all := []fileEntry{
		{path: "/v/alpha.md", mod: base},
		{path: "/v/alpha-new.md", mod: base.Add(24 * time.Hour)},
		{path: "/v/zzz.md", mod: base.Add(72 * time.Hour)},
	}
	got := rankEntries(all, "alpha", "")
	// zzz filtered out; both "alpha" files present, newer first on equal score is
	// not guaranteed (scores differ), but zzz must be absent.
	for _, p := range got {
		if p == "/v/zzz.md" {
			t.Error("zzz.md should not match query 'alpha'")
		}
	}
	if len(got) != 2 {
		t.Fatalf("got %d matches, want 2", len(got))
	}
}

func TestPickerPreviewRendersSelectedFile(t *testing.T) {
	root := t.TempDir()
	p := filepath.Join(root, "note.md")
	os.WriteFile(p, []byte("# Heading\n\nbody text"), 0o644)

	m, err := New(root, theme.FlexokiDark(), "", "dark")
	if err != nil {
		t.Fatal(err)
	}
	m.SetSize(120, 30)
	m.recompute() // selects note.md
	view := m.View()
	if !strings.Contains(view, "Heading") {
		t.Errorf("preview pane should render the selected file's heading; view:\n%s", view)
	}
}

func TestNewNotePath(t *testing.T) {
	root := "/v"
	cases := map[string]string{
		"foo":        filepath.Join("/v", "foo.md"),
		"Folder/Bar": filepath.Join("/v", "Folder", "Bar.md"),
		"x.md":       filepath.Join("/v", "x.md"),
		"  spaced  ": filepath.Join("/v", "spaced.md"),
	}
	for q, want := range cases {
		if got := NewNotePath(root, q); got != want {
			t.Errorf("NewNotePath(%q) = %q, want %q", q, got, want)
		}
	}
	if NewNotePath(root, "   ") != "" {
		t.Error("blank query should yield empty path")
	}
}