package store

import (
	"context"
	"reflect"
	"strings"
	"testing"
)

func TestDecodeWarnings(t *testing.T) {
	old := decodeWarnings(`["Only 3 of 9 folders match."]`)
	if len(old) != 1 || old[0].Title != "Only 3 of 9 folders match." {
		t.Fatalf("plain-string warnings from older scans should decode as titles, got %+v", old)
	}
	cur := decodeWarnings(`[{"title":"t","items":[{"slave":"a","master":"b","count":2}],"total":5}]`)
	if len(cur) != 1 || cur[0].Total != 5 || cur[0].Items[0].Count != 2 {
		t.Fatalf("structured warnings should round-trip, got %+v", cur)
	}
	if ws := decodeWarnings(`[]`); ws == nil || len(ws) != 0 {
		t.Fatalf("empty list should stay an empty (non-nil) list, got %#v", ws)
	}
}

func TestMatchLetters(t *testing.T) {
	ctx := context.Background()
	st, err := Open(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { st.DB.Close() })
	p := Pair{Name: "p", MasterRoot: "/m", SlaveRoot: "/s", RetentionDays: 30}
	if err := st.SavePair(ctx, &p); err != nil {
		t.Fatal(err)
	}
	for _, rel := range []string{"beck/a.flac", "ABBA/a.flac", "Air/a.flac", "2Pac/a.flac", "Björk/a.flac", "abba/b.flac"} {
		m := Match{PairID: p.ID, RelSlave: rel, Status: StatusUnmatched, Kind: KindNone}
		if err := st.UpsertMatch(ctx, &m); err != nil {
			t.Fatal(err)
		}
	}
	ls, err := st.MatchLetters(ctx, p.ID, MatchFilter{})
	if err != nil {
		t.Fatal(err)
	}
	want := []LetterStart{{"2", 0}, {"a", 1}, {"b", 4}}
	if !reflect.DeepEqual(ls, want) {
		t.Fatalf("letters = %+v, want %+v", ls, want)
	}
	// The offsets must agree with the listing order, whatever the case.
	ms, _, err := st.Matches(ctx, p.ID, MatchFilter{Limit: 10})
	if err != nil {
		t.Fatal(err)
	}
	for _, l := range ls {
		if got := strings.ToLower(ms[l.Offset].RelSlave[:1]); got != l.Letter {
			t.Fatalf("offset %d starts with %q, want %q (listing %v)", l.Offset, got, l.Letter, ms)
		}
	}
}