package schema

import (
	"os"
	"testing"
)

func TestParseSourceTranscriptJSON_BareArray(t *testing.T) {
	raw, err := os.ReadFile("testdata/transcript_bare_array.json")
	if err != nil {
		t.Fatalf("failed to read test fixture: %v", err)
	}

	transcript, err := ParseSourceTranscriptJSON(raw)
	if err != nil {
		t.Fatalf("ParseSourceTranscriptJSON failed: %v", err)
	}

	if len(transcript.Segments) != 2 {
		t.Fatalf("expected 2 segments, got %d", len(transcript.Segments))
	}

	s1 := transcript.Segments[0]
	if *s1.ID != 1 {
		t.Errorf("expected segment[0].id = 1, got %d", *s1.ID)
	}
	if s1.Speaker != "Alice" {
		t.Errorf("expected segment[0].speaker = Alice, got %q", s1.Speaker)
	}
	if s1.Start != 0.0 {
		t.Errorf("expected segment[0].start = 0.0, got %g", s1.Start)
	}
	if s1.End != 1.5 {
		t.Errorf("expected segment[0].end = 1.5, got %g", s1.End)
	}
	if s1.Text != "Hello world." {
		t.Errorf("expected segment[0].text = Hello world., got %q", s1.Text)
	}
	if s1.Categories != nil {
		t.Errorf("expected segment[0].categories = nil, got %v", s1.Categories)
	}

	s2 := transcript.Segments[1]
	if *s2.ID != 2 {
		t.Errorf("expected segment[1].id = 2, got %d", *s2.ID)
	}
	if len(s2.Categories) != 1 || s2.Categories[0] != "greeting" {
		t.Errorf("expected segment[1].categories = [greeting], got %v", s2.Categories)
	}
}

func TestParseSourceTranscriptJSON_ObjectWithSegments(t *testing.T) {
	raw, err := os.ReadFile("testdata/transcript_object.json")
	if err != nil {
		t.Fatalf("failed to read test fixture: %v", err)
	}

	transcript, err := ParseSourceTranscriptJSON(raw)
	if err != nil {
		t.Fatalf("ParseSourceTranscriptJSON failed: %v", err)
	}

	if len(transcript.Segments) != 2 {
		t.Fatalf("expected 2 segments, got %d", len(transcript.Segments))
	}

	if *transcript.Segments[0].ID != 1 {
		t.Errorf("expected segment[0].id = 1, got %d", *transcript.Segments[0].ID)
	}
}

func TestParseSourceTranscriptJSON_MalformedJSON(t *testing.T) {
	raw, err := os.ReadFile("testdata/transcript_malformed.json")
	if err != nil {
		t.Fatalf("failed to read test fixture: %v", err)
	}

	_, err = ParseSourceTranscriptJSON(raw)
	if err == nil {
		t.Fatal("expected error for malformed JSON, got nil")
	}

	parseErr, ok := err.(*ParseError)
	if !ok {
		t.Errorf("expected *ParseError, got %T", err)
	} else if parseErr.Message != "transcript is not valid JSON" {
		t.Errorf("expected 'transcript is not valid JSON', got %q", parseErr.Message)
	}
}

func TestParseSourceTranscriptJSON_EmptySpeaker(t *testing.T) {
	raw, err := os.ReadFile("testdata/transcript_empty_speaker.json")
	if err != nil {
		t.Fatalf("failed to read test fixture: %v", err)
	}

	_, err = ParseSourceTranscriptJSON(raw)
	if err == nil {
		t.Fatal("expected error for empty speaker, got nil")
	}

	assertValidationError(t, err, "speaker", "must not be empty")
}

func TestParseSourceTranscriptJSON_EmptyText(t *testing.T) {
	raw, err := os.ReadFile("testdata/transcript_empty_text.json")
	if err != nil {
		t.Fatalf("failed to read test fixture: %v", err)
	}

	_, err = ParseSourceTranscriptJSON(raw)
	if err == nil {
		t.Fatal("expected error for empty text, got nil")
	}

	assertValidationError(t, err, "text", "must not be empty")
}

func TestParseSourceTranscriptJSON_InvalidTimes(t *testing.T) {
	raw, err := os.ReadFile("testdata/transcript_invalid_times.json")
	if err != nil {
		t.Fatalf("failed to read test fixture: %v", err)
	}

	_, err = ParseSourceTranscriptJSON(raw)
	if err == nil {
		t.Fatal("expected error for invalid times, got nil")
	}

	assertValidationErrorContains(t, err, "end", "must be greater than or equal to start")
}

func TestParseSourceTranscriptJSON_DuplicateIDs(t *testing.T) {
	raw, err := os.ReadFile("testdata/transcript_duplicate_ids.json")
	if err != nil {
		t.Fatalf("failed to read test fixture: %v", err)
	}

	_, err = ParseSourceTranscriptJSON(raw)
	if err == nil {
		t.Fatal("expected error for duplicate IDs, got nil")
	}

	assertValidationErrorContains(t, err, "id", "duplicate id")
}

func TestParseSourceTranscriptJSON_EmptyArray(t *testing.T) {
	raw, err := os.ReadFile("testdata/transcript_empty_array.json")
	if err != nil {
		t.Fatalf("failed to read test fixture: %v", err)
	}

	_, err = ParseSourceTranscriptJSON(raw)
	if err == nil {
		t.Fatal("expected error for empty array, got nil")
	}

	parseErr, ok := err.(*ParseError)
	if !ok {
		t.Errorf("expected *ParseError, got %T", err)
	} else if parseErr.Message != "transcript must contain at least one segment" {
		t.Errorf("expected 'transcript must contain at least one segment', got %q", parseErr.Message)
	}
}

func TestParseTranscriptJSON_NonSequentialID(t *testing.T) {
	raw, err := os.ReadFile("testdata/transcript_non_sequential_id.json")
	if err != nil {
		t.Fatalf("failed to read test fixture: %v", err)
	}

	_, err = ParseTranscriptJSON(raw)
	if err == nil {
		t.Fatal("expected error for non-sequential ID, got nil")
	}

	assertValidationErrorContains(t, err, "id", "must be sequential")
}

func TestParseTranscriptJSONLenient_AssignsSequentialIDs(t *testing.T) {
	raw, err := os.ReadFile("testdata/transcript_no_ids.json")
	if err != nil {
		t.Fatalf("failed to read test fixture: %v", err)
	}

	transcript, err := ParseTranscriptJSONLenient(raw)
	if err != nil {
		t.Fatalf("ParseTranscriptJSONLenient failed: %v", err)
	}

	if len(transcript.Segments) != 2 {
		t.Fatalf("expected 2 segments, got %d", len(transcript.Segments))
	}

	if transcript.Segments[0].ID != 1 {
		t.Errorf("expected segment[0].id = 1, got %d", transcript.Segments[0].ID)
	}
	if transcript.Segments[1].ID != 2 {
		t.Errorf("expected segment[1].id = 2, got %d", transcript.Segments[1].ID)
	}
}

func TestParseSourceTranscriptJSON_UnsupportedTopLevelShape(t *testing.T) {
	raw := []byte(`"just a string"`)

	_, err := ParseSourceTranscriptJSON(raw)
	if err == nil {
		t.Fatal("expected error for unsupported top-level shape, got nil")
	}

	parseErr, ok := err.(*ParseError)
	if !ok {
		t.Errorf("expected *ParseError, got %T", err)
	} else if parseErr.Message != "transcript must be a JSON array or an object with a segments array" {
		t.Errorf("expected unsupported shape message, got %q", parseErr.Message)
	}
}

func TestParseSourceTranscriptJSON_ObjectWithoutSegments(t *testing.T) {
	raw := []byte(`{"metadata": {"version": "1.0"}}`)

	_, err := ParseSourceTranscriptJSON(raw)
	if err == nil {
		t.Fatal("expected error for object without segments, got nil")
	}

	parseErr, ok := err.(*ParseError)
	if !ok {
		t.Errorf("expected *ParseError, got %T", err)
	} else if parseErr.Message != "transcript object must contain a segments array" {
		t.Errorf("expected 'transcript object must contain a segments array', got %q", parseErr.Message)
	}
}

func TestTranscriptToJSON(t *testing.T) {
	transcript := &Transcript{
		Segments: []Segment{
			{ID: 1, Speaker: "Alice", Start: 0.0, End: 1.5, Text: "Hello world."},
			{ID: 2, Speaker: "Bob", Start: 2.0, End: 3.5, Text: "Hi there.", Categories: []string{"greeting"}},
		},
	}

	raw, err := TranscriptToJSON(transcript)
	if err != nil {
		t.Fatalf("TranscriptToJSON failed: %v", err)
	}

	parsed, err := ParseTranscriptJSON(raw)
	if err != nil {
		t.Fatalf("failed to parse round-trip JSON: %v", err)
	}

	if len(parsed.Segments) != 2 {
		t.Fatalf("expected 2 segments after round-trip, got %d", len(parsed.Segments))
	}

	if parsed.Segments[0].Speaker != "Alice" {
		t.Errorf("expected segment[0].speaker = Alice, got %q", parsed.Segments[0].Speaker)
	}
	if len(parsed.Segments[1].Categories) != 1 || parsed.Segments[1].Categories[0] != "greeting" {
		t.Errorf("expected segment[1].categories = [greeting], got %v", parsed.Segments[1].Categories)
	}
}

func assertValidationError(t *testing.T, err error, fieldContains, messageContains string) {
	t.Helper()

	valErr, ok := err.(*ValidationError)
	if !ok {
		t.Errorf("expected *ValidationError, got %T", err)
		return
	}

	if fieldContains != "" && valErr.Field == "" {
		t.Errorf("expected field to contain %q, got empty field", fieldContains)
	}
	if messageContains != "" && valErr.Message == "" {
		t.Errorf("expected message to contain %q, got empty message", messageContains)
	}
}

func assertValidationErrorContains(t *testing.T, err error, fieldContains, messageContains string) {
	t.Helper()

	valErr, ok := err.(*ValidationError)
	if !ok {
		t.Errorf("expected *ValidationError, got %T", err)
		return
	}

	if fieldContains != "" && valErr.Field == "" {
		t.Errorf("expected field to contain %q, got empty field", fieldContains)
	}
	if messageContains != "" && valErr.Message == "" {
		t.Errorf("expected message to contain %q, got empty message", messageContains)
	}
}