package schema

import (
	"strings"
	"testing"
)

func TestValidateTranscriptAcceptsValidTranscript(t *testing.T) {
	transcript := validTranscript()

	if err := ValidateTranscript(transcript); err != nil {
		t.Fatalf("validate transcript: %v", err)
	}
}

func TestValidateJSONRejectsMissingRequiredField(t *testing.T) {
	err := ValidateJSON([]byte(`{
		"metadata": {
			"application": "seriatim",
			"version": "dev",
			"input_reader": "json-files",
			"input_files": [],
			"preprocessing_modules": [],
			"postprocessing_modules": [],
			"output_modules": []
		},
		"segments": []
	}`))
	assertErrorContains(t, err, "overlap_groups")
}

func TestValidateJSONRejectsWrongFieldType(t *testing.T) {
	err := ValidateJSON([]byte(`{
		"metadata": {
			"application": "seriatim",
			"version": "dev",
			"input_reader": "json-files",
			"input_files": [],
			"preprocessing_modules": [],
			"postprocessing_modules": [],
			"output_modules": []
		},
		"segments": [
			{
				"id": "1",
				"source": "input.json",
				"speaker": "Alice",
				"start": 1,
				"end": 2,
				"text": "hello"
			}
		],
		"overlap_groups": []
	}`))
	assertErrorContains(t, err, "id")
}

func TestValidateJSONRejectsUnexpectedInternalFields(t *testing.T) {
	tests := []struct {
		name  string
		field string
	}{
		{name: "internal ref", field: `"internal_ref": "internal-1",`},
		{name: "words", field: `"words": [],`},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			err := ValidateJSON([]byte(`{
				"metadata": {
					"application": "seriatim",
					"version": "dev",
					"input_reader": "json-files",
					"input_files": [],
					"preprocessing_modules": [],
					"postprocessing_modules": [],
					"output_modules": []
				},
				"segments": [
					{
						"id": 1,
						` + test.field + `
						"source": "input.json",
						"speaker": "Alice",
						"start": 1,
						"end": 2,
						"text": "hello"
					}
				],
				"overlap_groups": []
			}`))
			assertErrorContains(t, err, "additional properties")
		})
	}
}

func TestValidateTranscriptRejectsMissingOrNonSequentialIDs(t *testing.T) {
	tests := []struct {
		name string
		ids  []int
		want string
	}{
		{name: "missing zero id", ids: []int{0}, want: "segment 0 has id 0; want 1"},
		{name: "does not start at one", ids: []int{2}, want: "segment 0 has id 2; want 1"},
		{name: "gap", ids: []int{1, 3}, want: "segment 1 has id 3; want 2"},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			transcript := validTranscript()
			transcript.Segments = transcript.Segments[:0]
			for index, id := range test.ids {
				transcript.Segments = append(transcript.Segments, Segment{
					ID:      id,
					Source:  "input.json",
					Speaker: "Alice",
					Start:   float64(index),
					End:     float64(index) + 1,
					Text:    "hello",
				})
			}

			err := ValidateTranscript(transcript)
			assertErrorContains(t, err, test.want)
		})
	}
}

func TestValidateTranscriptRejectsInvalidTiming(t *testing.T) {
	transcript := validTranscript()
	transcript.Segments[0].Start = 2
	transcript.Segments[0].End = 1

	err := ValidateTranscript(transcript)
	assertErrorContains(t, err, "segment 0 has end")
}

func TestValidateTranscriptRejectsInvalidOverlapGroupTiming(t *testing.T) {
	transcript := validTranscript()
	transcript.OverlapGroups = []OverlapGroup{
		{
			ID:         1,
			Start:      3,
			End:        2,
			Segments:   []string{"input.json#0"},
			Speakers:   []string{"Alice"},
			Class:      "unknown",
			Resolution: "unresolved",
		},
	}

	err := ValidateTranscript(transcript)
	assertErrorContains(t, err, "overlap_group 0 has end")
}

func validTranscript() Transcript {
	sourceIndex := 0
	return Transcript{
		Metadata: Metadata{
			Application:           "seriatim",
			Version:               "dev",
			InputReader:           "json-files",
			InputFiles:            []string{"input.json"},
			PreprocessingModules:  []string{"validate-raw", "normalize-speakers", "trim-text"},
			PostprocessingModules: []string{"assign-ids", "validate-output"},
			OutputModules:         []string{"json"},
		},
		Segments: []Segment{
			{
				ID:                 1,
				Source:             "input.json",
				SourceSegmentIndex: &sourceIndex,
				Speaker:            "Alice",
				Start:              1,
				End:                2,
				Text:               "hello",
			},
		},
		OverlapGroups: []OverlapGroup{},
	}
}

func assertErrorContains(t *testing.T, err error, want string) {
	t.Helper()
	if err == nil {
		t.Fatalf("expected error containing %q", want)
	}
	if !strings.Contains(err.Error(), want) {
		t.Fatalf("expected error containing %q, got %v", want, err)
	}
}