package aptrepo

import (
	"crypto/sha256"
	"fmt"
	"os"
	"path"
	"path/filepath"
	"reflect"
	"testing"

	"server-deploy/internal/installplan"
)

func artifactFixture(t *testing.T) (string, installplan.Lock) {
	t.Helper()
	dir := t.TempDir()
	index := fixtureIndex()
	lock, err := Resolve(fixtureRelease(index), index, "resolute", "amd64", fixturePins(), fixtureNow)
	if err != nil {
		t.Fatal(err)
	}
	for i := range lock.Packages {
		p := &lock.Packages[i]
		data := []byte("artifact fixture " + p.Name)
		p.Size = uint64(len(data))
		p.Digest = fmt.Sprintf("sha256:%x", sha256.Sum256(data))
		if err := os.WriteFile(filepath.Join(dir, path.Base(p.Filename)), data, 0600); err != nil {
			t.Fatal(err)
		}
	}
	return dir, lock
}

func TestArtifactBytesAndIdentity(t *testing.T) {
	dir, lock := artifactFixture(t)
	before := lock
	before.Packages = append([]installplan.Package(nil), lock.Packages...)
	if err := verifyArtifacts(dir, lock); err != nil {
		t.Fatal(err)
	}
	if !reflect.DeepEqual(before, lock) {
		t.Fatal("lock mutated")
	}
	for _, p := range lock.Packages {
		data, err := os.ReadFile(filepath.Join(dir, path.Base(p.Filename)))
		if err != nil || string(data) != "artifact fixture "+p.Name {
			t.Fatal("artifact modified")
		}
	}
}

func TestArtifactRejectsTamperWithoutPartialSuccess(t *testing.T) {
	for _, kind := range []string{"same-size", "truncated", "extra-byte", "missing", "directory", "bad-lock", "relative-root", "extra-file"} {
		t.Run(kind, func(t *testing.T) {
			dir, lock := artifactFixture(t)
			p := lock.Packages[4] // The last artifact must fail the whole set.
			filename := filepath.Join(dir, path.Base(p.Filename))
			switch kind {
			case "same-size":
				data := []byte("artifact fixture " + p.Name)
				data[0] = 'X'
				if err := os.WriteFile(filename, data, 0600); err != nil {
					t.Fatal(err)
				}
			case "truncated":
				if err := os.Truncate(filename, int64(p.Size)-1); err != nil {
					t.Fatal(err)
				}
			case "extra-byte":
				if err := os.Truncate(filename, int64(p.Size)+1); err != nil {
					t.Fatal(err)
				}
			case "missing":
				if err := os.Remove(filename); err != nil {
					t.Fatal(err)
				}
			case "directory":
				if err := os.Remove(filename); err != nil {
					t.Fatal(err)
				}
				if err := os.Mkdir(filename, 0700); err != nil {
					t.Fatal(err)
				}
			case "bad-lock":
				lock.Packages[0].Filename = "../../secret.deb"
			case "relative-root":
				dir = "relative"
			case "extra-file":
				if err := os.WriteFile(filepath.Join(dir, "unexpected.deb"), []byte("x"), 0600); err != nil {
					t.Fatal(err)
				}
			}
			if err := verifyArtifacts(dir, lock); err == nil {
				t.Fatal("invalid artifacts accepted")
			}
		})
	}
}