package mdl

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

func writeMDL(t *testing.T, name, body string) string {
	t.Helper()
	p := filepath.Join(t.TempDir(), name)
	if err := os.WriteFile(p, []byte(body), 0o644); err != nil {
		t.Fatal(err)
	}
	return p
}

func TestIsASCII(t *testing.T) {
	ascii := writeMDL(t, "foo.mdl", "newmodel foo\nbeginmodelgeom foo\n")
	if ok, err := IsASCII(ascii); err != nil || !ok {
		t.Fatalf("ascii: ok=%v err=%v, want true nil", ok, err)
	}
	bin := writeMDL(t, "bar.mdl", "\x00\x01binary\x00garbage")
	if ok, err := IsASCII(bin); err != nil || ok {
		t.Fatalf("binary: ok=%v err=%v, want false nil", ok, err)
	}
	hash := writeMDL(t, "baz.mdl", "# a comment\nnewmodel baz\n")
	if ok, _ := IsASCII(hash); !ok {
		t.Fatal("leading # should be ascii")
	}
}

func TestExpectedName(t *testing.T) {
	for in, want := range map[string]string{
		"a/b/Foo.MDL":     "Foo",
		"waxbt_b_091.mdl": "waxbt_b_091",
		"x.mdl":           "x",
	} {
		if got := ExpectedName(in); got != want {
			t.Errorf("ExpectedName(%q)=%q want %q", in, got, want)
		}
	}
}

func TestCheckNames(t *testing.T) {
	// Header token mismatch + base-node mismatch in one file.
	body := "newmodel wrong\n" +
		"setsupermodel wrong a_base\n" +
		"beginmodelgeom foo\n" +
		"  node dummy Wmgst_m_081\n" +
		"    parent null\n" +
		"  endnode\n" +
		"endmodelgeom foo\n" +
		"donemodel foo\n"
	p := writeMDL(t, "foo.mdl", body)
	got, err := CheckNames(p)
	if err != nil {
		t.Fatal(err)
	}
	// Expected stem "foo": newmodel(wrong), setsupermodel(wrong), base node(Wmgst_m_081).
	if len(got) != 3 {
		t.Fatalf("got %d mismatches, want 3: %+v", len(got), got)
	}
	if got[0].What != "newmodel" || got[0].Got != "wrong" || got[0].Line != 1 {
		t.Errorf("first mismatch = %+v", got[0])
	}
	base := got[len(got)-1]
	if base.What != "root node" || base.Got != "Wmgst_m_081" || base.Line != 0 {
		t.Errorf("base mismatch = %+v", base)
	}

	// Clean model -> no mismatches.
	clean := writeMDL(t, "bar.mdl",
		"newmodel bar\nbeginmodelgeom bar\n  node dummy bar\n    parent null\n  endnode\nendmodelgeom bar\ndonemodel bar\n")
	if got, _ := CheckNames(clean); len(got) != 0 {
		t.Fatalf("clean model reported mismatches: %+v", got)
	}

	// Binary model -> nil, no error.
	bin := writeMDL(t, "b.mdl", "\x00\x00binary")
	if got, _ := CheckNames(bin); got != nil {
		t.Fatalf("binary reported mismatches: %+v", got)
	}
}

func TestFixNamesRoundTrips(t *testing.T) {
	body := "newmodel wrong\n" +
		"setsupermodel wrong\n" +
		"beginmodelgeom wrong\n" +
		"  node dummy Wmgst_m_081\n" +
		"    parent null\n" +
		"  endnode\n" +
		"endmodelgeom wrong\n" +
		"donemodel wrong\n"
	out, changed := FixNames([]byte(body), "foo")
	if !changed {
		t.Fatal("expected changed=true")
	}
	p := filepath.Join(t.TempDir(), "foo.mdl")
	if err := os.WriteFile(p, out, 0o644); err != nil {
		t.Fatal(err)
	}
	got, err := CheckNames(p)
	if err != nil {
		t.Fatal(err)
	}
	if len(got) != 0 {
		t.Fatalf("fixed model still has mismatches: %+v\n%s", got, out)
	}
	// Idempotent: fixing a clean model changes nothing.
	if _, changed := FixNames(out, "foo"); changed {
		t.Fatal("second fix reported a change")
	}
}