package storage

import (
	"context"
	"errors"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestFakeBackendListPrefixFiltering(t *testing.T) {
	fake := &FakeBackend{}
	fake.SeedObject(FakeObject{Key: "dnd/campaigns/forsaken/audio/a.flac", Data: []byte("a")})
	fake.SeedObject(FakeObject{Key: "dnd/campaigns/forsaken/audio/b.flac", Data: []byte("b")})
	fake.SeedObject(FakeObject{Key: "dnd/campaigns/other/audio/c.flac", Data: []byte("c")})

	items, err := fake.List(context.Background(), "dnd/campaigns/forsaken/audio/")
	if err != nil {
		t.Fatalf("List() error = %v", err)
	}
	if len(items) != 2 {
		t.Fatalf("List() len = %d, want 2", len(items))
	}
	if items[0].Key != "dnd/campaigns/forsaken/audio/a.flac" || items[1].Key != "dnd/campaigns/forsaken/audio/b.flac" {
		t.Fatalf("List() keys = %#v", items)
	}
}

func TestFakeBackendDownload(t *testing.T) {
	fake := &FakeBackend{}
	fake.SeedObject(FakeObject{Key: "audio/a.flac", Data: []byte("audio-a")})

	dst := filepath.Join(t.TempDir(), "nested", "a.flac")
	if err := fake.Download(context.Background(), `audio\a.flac`, dst); err != nil {
		t.Fatalf("Download() error = %v", err)
	}
	data, err := os.ReadFile(dst)
	if err != nil {
		t.Fatalf("ReadFile() error = %v", err)
	}
	if string(data) != "audio-a" {
		t.Fatalf("downloaded content = %q, want %q", string(data), "audio-a")
	}
}

func TestFakeBackendUploadAndExists(t *testing.T) {
	fake := &FakeBackend{}

	local := filepath.Join(t.TempDir(), "upload.txt")
	if err := os.WriteFile(local, []byte("payload"), 0o644); err != nil {
		t.Fatalf("WriteFile() error = %v", err)
	}

	info, err := fake.Upload(context.Background(), local, `runs\id\artifact.txt`, UploadOptions{
		Metadata: map[string]string{"kind": "artifact"},
	})
	if err != nil {
		t.Fatalf("Upload() error = %v", err)
	}
	if info.Key != "runs/id/artifact.txt" {
		t.Fatalf("Upload() key = %q, want normalized key", info.Key)
	}

	ok, err := fake.Exists(context.Background(), "runs/id/artifact.txt")
	if err != nil {
		t.Fatalf("Exists() error = %v", err)
	}
	if !ok {
		t.Fatal("Exists() = false, want true")
	}
}

func TestFakeBackendConditionalUploadRejectsStaleGeneration(t *testing.T) {
	fake := &FakeBackend{}
	fake.SeedObject(FakeObject{Key: "locks.yml", Data: []byte("old")})
	old := fake.Objects["locks.yml"].ETag
	if _, err := fake.UploadConditional(context.Background(), strings.NewReader("new"), "locks.yml", UploadOptions{}, WriteCondition{MatchETag: old}); err != nil {
		t.Fatalf("UploadConditional() error = %v", err)
	}
	if _, err := fake.UploadConditional(context.Background(), strings.NewReader("lost"), "locks.yml", UploadOptions{}, WriteCondition{MatchETag: old}); !errors.Is(err, ErrConditionNotMet) {
		t.Fatalf("UploadConditional() error = %v, want ErrConditionNotMet", err)
	}
	if got := string(fake.Objects["locks.yml"].Data); got != "new" {
		t.Fatalf("locks object = %q, want successful replacement preserved", got)
	}
}

func TestFakeBackendObjectErrors(t *testing.T) {
	fake := &FakeBackend{DownloadErr: errors.New("download fail"), UploadErr: errors.New("upload fail"), ListErr: errors.New("list fail"), ExistsErr: errors.New("exists fail")}

	if _, err := fake.List(context.Background(), "x"); err == nil || !strings.Contains(err.Error(), "list fail") {
		t.Fatalf("List() error = %v, want list fail", err)
	}
	if err := fake.Download(context.Background(), "x", filepath.Join(t.TempDir(), "x")); err == nil || !strings.Contains(err.Error(), "download fail") {
		t.Fatalf("Download() error = %v, want download fail", err)
	}
	local := filepath.Join(t.TempDir(), "x.txt")
	_ = os.WriteFile(local, []byte("x"), 0o644)
	if _, err := fake.Upload(context.Background(), local, "x", UploadOptions{}); err == nil || !strings.Contains(err.Error(), "upload fail") {
		t.Fatalf("Upload() error = %v, want upload fail", err)
	}
	if _, err := fake.Exists(context.Background(), "x"); err == nil || !strings.Contains(err.Error(), "exists fail") {
		t.Fatalf("Exists() error = %v, want exists fail", err)
	}
}