package typdoc

import (
	"flag"
	"os"
	"path/filepath"
	"testing"

	"ukrrs.com/mopac/pdf/internal/frontmatter"
	"ukrrs.com/mopac/pdf/internal/markdown"
)

var update = flag.Bool("update", false, "rewrite golden files")

// Golden: fixture markdown -> composed typst document. The chart renderer
// and image stager are stubbed with deterministic bytes; golden files pin
// the emitted typst markup and template composition.
func TestGoldenCompose(t *testing.T) {
	for _, fixture := range []string{"sample-report", "sample-brief"} {
		t.Run(fixture, func(t *testing.T) {
			src, err := os.ReadFile(filepath.Join("..", "..", "testdata", fixture+".md"))
			if err != nil {
				t.Fatal(err)
			}
			meta, body, err := frontmatter.Split(string(src))
			if err != nil {
				t.Fatal(err)
			}
			name := meta.Template
			if name == "" {
				name = "report"
			}
			assets := Assets{}
			rendered, err := RenderBody(markdown.Parse(body), assets, Funcs{
				RenderChart: func(*markdown.Chart, string) ([]byte, error) { return []byte("PNG-STUB"), nil },
				StageImage:  func(string, string) ([]byte, error) { return []byte("IMG-STUB"), nil },
			})
			if err != nil {
				t.Fatal(err)
			}
			doc := Compose(name, meta, rendered)
			golden := filepath.Join("..", "..", "testdata", fixture+".typ.golden")
			if *update {
				if err := os.WriteFile(golden, []byte(doc), 0o644); err != nil {
					t.Fatal(err)
				}
				return
			}
			want, err := os.ReadFile(golden)
			if err != nil {
				t.Fatalf("golden missing (run go test ./internal/typdoc -update): %v", err)
			}
			if doc != string(want) {
				t.Errorf("composed typst drifted from golden %s", golden)
			}
			if len(assets) == 0 {
				t.Errorf("expected chart asset to be staged")
			}
		})
	}
}

func TestInlineEscapes(t *testing.T) {
	cases := map[string]string{
		"a # b":                 `a \# b`,
		"cost $5 @here":         `cost \$5 \@here`,
		"x [y] z":               `x \[y\] z`,
		"**b** and *i*":         `*b* and _i_`,
		"`c`":                   "`c`",
		"[t](https://x.co/a)":   `#link("https://x.co/a")[t]`,
		"see [docs](/a/b) here": `see #link("/a/b")[docs] here`,
		"~tilde":                `\~tilde`,
	}
	for in, want := range cases {
		if got := inline(in); got != want {
			t.Errorf("inline(%q) = %q want %q", in, got, want)
		}
	}
}

func TestTypstString(t *testing.T) {
	if got := typstString(`a "b" \c` + "\n"); got != `"a \"b\" \\c\n"` {
		t.Fatalf("got %s", got)
	}
}

func TestComposePreamble(t *testing.T) {
	doc := Compose("brief", frontmatter.Meta{Title: "T"}, "BODY")
	want := "#import \"/template.typ\": brief\n#show: brief.with(\n  title: \"T\",\n  subtitle: \"\",\n  author: \"\",\n  date: \"\",\n  classification: \"\",\n)\n\nBODY"
	if doc != want {
		t.Fatalf("got:\n%s", doc)
	}
}