package coalesce

import (
	"reflect"
	"testing"

	"gitea.maximumdirect.net/eric/seriatim/internal/model"
)

func TestApplyMergesConsecutiveSameSpeakerWithinGap(t *testing.T) {
	merged := model.MergedTranscript{
		Segments: []model.Segment{
			segment("a.json", 0, "Alice", 1, 2, " first "),
			segment("a.json", 1, "Alice", 4, 5, "second"),
		},
	}

	got, summary := Apply(merged, 3)
	if summary.OriginalSegmentsMerged != 2 || summary.CoalescedSegments != 1 {
		t.Fatalf("summary = %#v", summary)
	}
	if len(got.Segments) != 1 {
		t.Fatalf("segment count = %d, want 1", len(got.Segments))
	}
	segment := got.Segments[0]
	if segment.Text != "first second" {
		t.Fatalf("text = %q", segment.Text)
	}
	if segment.Start != 1 || segment.End != 5 {
		t.Fatalf("bounds = %f-%f, want 1-5", segment.Start, segment.End)
	}
	if segment.Source != "a.json" {
		t.Fatalf("source = %q, want a.json", segment.Source)
	}
	if segment.SourceRef != "coalesce:1" {
		t.Fatalf("source_ref = %q, want coalesce:1", segment.SourceRef)
	}
	if segment.SourceSegmentIndex != nil {
		t.Fatalf("source_segment_index = %d, want nil", *segment.SourceSegmentIndex)
	}
	if !reflect.DeepEqual(segment.DerivedFrom, []string{"a.json#0", "a.json#1"}) {
		t.Fatalf("derived_from = %v", segment.DerivedFrom)
	}
}

func TestApplyDoesNotMergeSameSpeakerBeyondGap(t *testing.T) {
	merged := model.MergedTranscript{
		Segments: []model.Segment{
			segment("a.json", 0, "Alice", 1, 2, "first"),
			segment("a.json", 1, "Alice", 5.1, 6, "second"),
		},
	}

	got, summary := Apply(merged, 3)
	if summary.OriginalSegmentsMerged != 0 || summary.CoalescedSegments != 0 {
		t.Fatalf("summary = %#v", summary)
	}
	if !reflect.DeepEqual(got.Segments, merged.Segments) {
		t.Fatalf("segments changed:\ngot  %#v\nwant %#v", got.Segments, merged.Segments)
	}
}

func TestApplyDoesNotMergeAcrossDifferentSpeaker(t *testing.T) {
	merged := model.MergedTranscript{
		Segments: []model.Segment{
			segment("a.json", 0, "Alice", 1, 2, "first"),
			segment("b.json", 0, "Bob", 2.5, 3, "bob"),
			segment("a.json", 1, "Alice", 3.5, 4, "second"),
		},
	}

	got, summary := Apply(merged, 3)
	if summary.OriginalSegmentsMerged != 0 || summary.CoalescedSegments != 0 {
		t.Fatalf("summary = %#v", summary)
	}
	if len(got.Segments) != 3 {
		t.Fatalf("segment count = %d, want 3", len(got.Segments))
	}
}

func TestApplyMergesNegativeGapOverlap(t *testing.T) {
	merged := model.MergedTranscript{
		Segments: []model.Segment{
			segment("a.json", 0, "Alice", 1, 4, "first"),
			segment("a.json", 1, "Alice", 3, 5, "second"),
		},
	}

	got, summary := Apply(merged, 0)
	if summary.OriginalSegmentsMerged != 2 || summary.CoalescedSegments != 1 {
		t.Fatalf("summary = %#v", summary)
	}
	if got.Segments[0].Start != 1 || got.Segments[0].End != 5 {
		t.Fatalf("bounds = %f-%f, want 1-5", got.Segments[0].Start, got.Segments[0].End)
	}
}

func TestApplyHonorsCurrentOrder(t *testing.T) {
	merged := model.MergedTranscript{
		Segments: []model.Segment{
			segment("a.json", 0, "Alice", 10, 11, "later"),
			segment("a.json", 1, "Alice", 1, 2, "earlier"),
		},
	}

	got, summary := Apply(merged, 3)
	if summary.OriginalSegmentsMerged != 2 || summary.CoalescedSegments != 1 {
		t.Fatalf("summary = %#v", summary)
	}
	if got.Segments[0].Text != "later earlier" {
		t.Fatalf("text = %q, want current-order merge", got.Segments[0].Text)
	}
	if got.Segments[0].Start != 1 || got.Segments[0].End != 11 {
		t.Fatalf("bounds = %f-%f, want 1-11", got.Segments[0].Start, got.Segments[0].End)
	}
}

func TestApplyDerivedProvenanceForMixedSourcesAndDerivedInputs(t *testing.T) {
	first := segment("a.json", 0, "Alice", 1, 2, "first")
	second := model.Segment{
		Source:      "b.json",
		SourceRef:   "word-run:1:1:1",
		DerivedFrom: []string{"b.json#0"},
		Speaker:     "Alice",
		Start:       2.5,
		End:         3,
		Text:        "second",
	}

	got, _ := Apply(model.MergedTranscript{Segments: []model.Segment{first, second}}, 3)
	segment := got.Segments[0]
	if segment.Source != "derived" {
		t.Fatalf("source = %q, want derived", segment.Source)
	}
	if !reflect.DeepEqual(segment.DerivedFrom, []string{"a.json#0", "word-run:1:1:1"}) {
		t.Fatalf("derived_from = %v", segment.DerivedFrom)
	}
}

func TestApplyDropsBackchannelCategoryFromMergedSameSpeakerRun(t *testing.T) {
	first := segment("a.json", 0, "Alice", 1, 2, "yeah")
	first.Categories = []string{"backchannel"}
	second := segment("a.json", 1, "Alice", 2.5, 3, "more")

	got, _ := Apply(model.MergedTranscript{Segments: []model.Segment{first, second}}, 3)
	if len(got.Segments) != 1 {
		t.Fatalf("segment count = %d, want 1", len(got.Segments))
	}
	if got.Segments[0].Categories != nil {
		t.Fatalf("categories = %v, want nil", got.Segments[0].Categories)
	}
}

func TestApplyDropsFillerCategoryFromMergedSameSpeakerRun(t *testing.T) {
	first := segment("a.json", 0, "Alice", 1, 2, "um")
	first.Categories = []string{"filler"}
	second := segment("a.json", 1, "Alice", 2.5, 3, "more")

	got, _ := Apply(model.MergedTranscript{Segments: []model.Segment{first, second}}, 3)
	if len(got.Segments) != 1 {
		t.Fatalf("segment count = %d, want 1", len(got.Segments))
	}
	if got.Segments[0].Categories != nil {
		t.Fatalf("categories = %v, want nil", got.Segments[0].Categories)
	}
}

func TestApplyMergesSameSpeakerBackchannelIntoDerivedRun(t *testing.T) {
	first := segment("zach.json", 110, "Zach", 7811.778, 7812.478, "That makes sense.")
	first.Categories = []string{"backchannel"}
	second := model.Segment{
		Source:      "zach.json",
		SourceRef:   "coalesce:347",
		DerivedFrom: []string{"zach.json#111", "zach.json#112"},
		Speaker:     "Zach",
		Start:       7812.498,
		End:         7824.045,
		Text:        "So, like, I'm above the silence field.",
	}

	got, summary := Apply(model.MergedTranscript{Segments: []model.Segment{first, second}}, 3)
	if summary.OriginalSegmentsMerged != 2 || summary.CoalescedSegments != 1 {
		t.Fatalf("summary = %#v", summary)
	}
	if len(got.Segments) != 1 {
		t.Fatalf("segment count = %d, want 1", len(got.Segments))
	}
	if got.Segments[0].Text != "That makes sense. So, like, I'm above the silence field." {
		t.Fatalf("text = %q", got.Segments[0].Text)
	}
	if got.Segments[0].SourceRef != "coalesce:1" {
		t.Fatalf("source_ref = %q, want coalesce:1", got.Segments[0].SourceRef)
	}
	if !reflect.DeepEqual(got.Segments[0].DerivedFrom, []string{"zach.json#110", "coalesce:347"}) {
		t.Fatalf("derived_from = %v", got.Segments[0].DerivedFrom)
	}
	if got.Segments[0].Categories != nil {
		t.Fatalf("categories = %v, want nil", got.Segments[0].Categories)
	}
}

func TestApplyMergesSameSpeakerFillerIntoDerivedRun(t *testing.T) {
	first := segment("zach.json", 110, "Zach", 1, 1.5, "um")
	first.Categories = []string{"filler"}
	second := model.Segment{
		Source:      "zach.json",
		SourceRef:   "coalesce:12",
		DerivedFrom: []string{"zach.json#111", "zach.json#112"},
		Speaker:     "Zach",
		Start:       1.6,
		End:         4,
		Text:        "next thought",
	}

	got, summary := Apply(model.MergedTranscript{Segments: []model.Segment{first, second}}, 3)
	if summary.OriginalSegmentsMerged != 2 || summary.CoalescedSegments != 1 {
		t.Fatalf("summary = %#v", summary)
	}
	if len(got.Segments) != 1 {
		t.Fatalf("segment count = %d, want 1", len(got.Segments))
	}
	if got.Segments[0].Text != "um next thought" {
		t.Fatalf("text = %q", got.Segments[0].Text)
	}
	if !reflect.DeepEqual(got.Segments[0].DerivedFrom, []string{"zach.json#110", "coalesce:12"}) {
		t.Fatalf("derived_from = %v", got.Segments[0].DerivedFrom)
	}
	if got.Segments[0].Categories != nil {
		t.Fatalf("categories = %v, want nil", got.Segments[0].Categories)
	}
}

func TestApplyUsesSkippedBackchannelToSeedNextSameSpeakerRun(t *testing.T) {
	mike := segment("mike.json", 367, "Mike", 7803.57, 7810.719, "It's very easy to notice.")
	backchannel := segment("zach.json", 110, "Zach", 7811.778, 7812.478, "That makes sense.")
	backchannel.Categories = []string{"backchannel"}
	next := segment("zach.json", 111, "Zach", 7812.498, 7820, "So, like, next thought.")

	got, summary := Apply(model.MergedTranscript{Segments: []model.Segment{mike, backchannel, next}}, 3)
	if summary.OriginalSegmentsMerged != 2 || summary.CoalescedSegments != 1 {
		t.Fatalf("summary = %#v", summary)
	}
	if len(got.Segments) != 2 {
		t.Fatalf("segment count = %d, want 2", len(got.Segments))
	}
	if got.Segments[0].Text != "It's very easy to notice." {
		t.Fatalf("first text = %q", got.Segments[0].Text)
	}
	if got.Segments[1].Speaker != "Zach" || got.Segments[1].Text != "That makes sense. So, like, next thought." {
		t.Fatalf("second segment = %#v", got.Segments[1])
	}
	if !reflect.DeepEqual(got.Segments[1].DerivedFrom, []string{"zach.json#110", "zach.json#111"}) {
		t.Fatalf("derived_from = %v", got.Segments[1].DerivedFrom)
	}
	if got.Segments[1].Categories != nil {
		t.Fatalf("categories = %v, want nil", got.Segments[1].Categories)
	}
}

func TestApplyUsesSkippedFillerToSeedNextSameSpeakerRun(t *testing.T) {
	alice := segment("alice.json", 0, "Alice", 1, 2, "first")
	filler := segment("bob.json", 0, "Bob", 2.1, 2.3, "um")
	filler.Categories = []string{"filler"}
	bob := segment("bob.json", 1, "Bob", 2.4, 4, "actual thought")

	got, summary := Apply(model.MergedTranscript{Segments: []model.Segment{alice, filler, bob}}, 3)
	if summary.OriginalSegmentsMerged != 2 || summary.CoalescedSegments != 1 {
		t.Fatalf("summary = %#v", summary)
	}
	if len(got.Segments) != 2 {
		t.Fatalf("segment count = %d, want 2", len(got.Segments))
	}
	if got.Segments[1].Text != "um actual thought" {
		t.Fatalf("second text = %q", got.Segments[1].Text)
	}
	if got.Segments[1].Categories != nil {
		t.Fatalf("categories = %v, want nil", got.Segments[1].Categories)
	}
}

func TestApplySkipsDifferentSpeakerBackchannelAsMergeBlocker(t *testing.T) {
	first := segment("a.json", 0, "Alice", 1, 2, "first")
	backchannel := segment("b.json", 0, "Bob", 2.2, 2.5, "yeah")
	backchannel.Categories = []string{"backchannel"}
	second := segment("a.json", 1, "Alice", 3, 4, "second")

	got, summary := Apply(model.MergedTranscript{Segments: []model.Segment{first, backchannel, second}}, 3)
	if summary.OriginalSegmentsMerged != 2 || summary.CoalescedSegments != 1 {
		t.Fatalf("summary = %#v", summary)
	}
	if len(got.Segments) != 2 {
		t.Fatalf("segment count = %d, want 2", len(got.Segments))
	}
	if got.Segments[0].Text != "first second" {
		t.Fatalf("first output text = %q, want first second", got.Segments[0].Text)
	}
	if got.Segments[1].Text != "yeah" || !reflect.DeepEqual(got.Segments[1].Categories, []string{"backchannel"}) {
		t.Fatalf("second output segment = %#v", got.Segments[1])
	}
}

func TestApplySkipsDifferentSpeakerFillerAsMergeBlocker(t *testing.T) {
	first := segment("a.json", 0, "Alice", 1, 2, "first")
	filler := segment("b.json", 0, "Bob", 2.2, 2.5, "um")
	filler.Categories = []string{"filler"}
	second := segment("a.json", 1, "Alice", 3, 4, "second")

	got, summary := Apply(model.MergedTranscript{Segments: []model.Segment{first, filler, second}}, 3)
	if summary.OriginalSegmentsMerged != 2 || summary.CoalescedSegments != 1 {
		t.Fatalf("summary = %#v", summary)
	}
	if len(got.Segments) != 2 {
		t.Fatalf("segment count = %d, want 2", len(got.Segments))
	}
	if got.Segments[0].Text != "first second" {
		t.Fatalf("first output text = %q, want first second", got.Segments[0].Text)
	}
	if got.Segments[1].Text != "um" || !reflect.DeepEqual(got.Segments[1].Categories, []string{"filler"}) {
		t.Fatalf("second output segment = %#v", got.Segments[1])
	}
}

func TestApplyDifferentSpeakerNonBackchannelStillBlocksMerge(t *testing.T) {
	first := segment("a.json", 0, "Alice", 1, 2, "first")
	bob := segment("b.json", 0, "Bob", 2.2, 2.5, "interruption")
	second := segment("a.json", 1, "Alice", 3, 4, "second")

	got, summary := Apply(model.MergedTranscript{Segments: []model.Segment{first, bob, second}}, 3)
	if summary.OriginalSegmentsMerged != 0 || summary.CoalescedSegments != 0 {
		t.Fatalf("summary = %#v", summary)
	}
	if len(got.Segments) != 3 {
		t.Fatalf("segment count = %d, want 3", len(got.Segments))
	}
}

func segment(source string, sourceIndex int, speaker string, start float64, end float64, text string) model.Segment {
	return model.Segment{
		Source:             source,
		SourceSegmentIndex: intPtr(sourceIndex),
		Speaker:            speaker,
		Start:              start,
		End:                end,
		Text:               text,
		Words: []model.Word{
			{Text: text, Start: start, End: end, Timed: true},
		},
	}
}

func intPtr(value int) *int {
	return &value
}