package storage

import (
	"context"
	"errors"
	"testing"
)

type listedParts struct {
	MultipartStore
	parts []Part
	calls int
	loop  bool
}

func (s *listedParts) ListParts(ctx context.Context, u MultipartUpload, marker, limit int) (PartsPage, error) {
	s.calls++
	if s.loop {
		return PartsPage{Parts: []Part{{Number: 1, ETag: "a", Size: 5 << 20}}, NextMarker: marker}, nil
	}
	end := min(marker+limit, len(s.parts))
	next := 0
	if end < len(s.parts) {
		next = end
	}
	return PartsPage{Parts: s.parts[marker:end], NextMarker: next}, nil
}
func TestVerifyPartsUsesProviderSizes(t *testing.T) {
	upload := MultipartUpload{Key: "file", UploadID: "id"}
	first := Part{Number: 1, ETag: "a", Size: 5 << 20}
	last := Part{Number: 2, ETag: "b", Size: 3}
	supplied := []Part{{Number: 1, ETag: "a", Size: 1}, {Number: 2, ETag: "b", Size: 1}}
	s := &listedParts{parts: []Part{first, last}}
	n, err := VerifyParts(context.Background(), s, upload, supplied, 6<<20)
	if err != nil || n != (5<<20)+3 {
		t.Fatal(n, err)
	}
	if _, err = VerifyParts(context.Background(), s, upload, supplied, 5<<20); !errors.Is(err, ErrTooLarge) {
		t.Fatal(err)
	}
	for _, parts := range [][]Part{nil, {last, first}, {first, first}, {{Number: 1, ETag: "changed"}, last}, {first}} {
		if _, err := VerifyParts(context.Background(), s, upload, parts, 6<<20); err == nil {
			t.Fatal("bad completion accepted", parts)
		}
	}
	s.parts[0].Size = 1
	if _, err = VerifyParts(context.Background(), s, upload, supplied, 6<<20); err == nil {
		t.Fatal("small non-final part accepted")
	}
}
func TestVerifyPartsPagination(t *testing.T) {
	s := &listedParts{}
	for i := 1; i <= 1001; i++ {
		s.parts = append(s.parts, Part{Number: i, ETag: "etag", Size: 5 << 20})
	}
	n, err := VerifyParts(context.Background(), s, MultipartUpload{Key: "file", UploadID: "id"}, s.parts, 10<<30)
	if err != nil || s.calls != 2 || n != 1001*(5<<20) {
		t.Fatal(n, s.calls, err)
	}
}