package parser

import (
	"testing"
)

func TestSplitFrontmatter(t *testing.T) {
	tests := []struct {
		name     string
		input    string
		wantFM   string
		wantBody string
	}{
		{
			name:     "no frontmatter",
			input:    "# Just markdown\n",
			wantFM:   "",
			wantBody: "# Just markdown\n",
		},
		{
			name:     "with frontmatter",
			input:    "---\ntitle: Hello\n---\n# Body\n",
			wantFM:   "title: Hello",
			wantBody: "# Body\n",
		},
		{
			name:     "frontmatter with no trailing body",
			input:    "---\ntitle: Hello\n---\n",
			wantFM:   "title: Hello",
			wantBody: "",
		},
		{
			name:     "unterminated frontmatter treated as body",
			input:    "---\ntitle: Hello\n# Body\n",
			wantFM:   "",
			wantBody: "---\ntitle: Hello\n# Body\n",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			fm, body := splitFrontmatter([]byte(tt.input))
			if string(fm) != tt.wantFM {
				t.Errorf("frontmatter = %q, want %q", fm, tt.wantFM)
			}
			if string(body) != tt.wantBody {
				t.Errorf("body = %q, want %q", body, tt.wantBody)
			}
		})
	}
}

func TestParseFrontmatter(t *testing.T) {
	tests := []struct {
		name    string
		input   string
		want    frontmatter
		wantErr bool
	}{
		{
			name:  "all fields",
			input: "---\ntitle: Intro\nclass: center\nnotes: speaker notes\nskip: true\nincremental: true\n---\nbody\n",
			want:  frontmatter{Title: "Intro", Class: "center", Notes: "speaker notes", Skip: true, Incremental: true},
		},
		{
			name:  "no frontmatter defaults to zero values",
			input: "just body\n",
			want:  frontmatter{},
		},
		{
			name:    "invalid yaml",
			input:   "---\ntitle: [unterminated\n---\nbody\n",
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, _, err := parseFrontmatter([]byte(tt.input))
			if (err != nil) != tt.wantErr {
				t.Fatalf("err = %v, wantErr %v", err, tt.wantErr)
			}
			if err != nil {
				return
			}
			if got != tt.want {
				t.Errorf("frontmatter = %+v, want %+v", got, tt.want)
			}
		})
	}
}