package zeta

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

// validManifest returns a fully valid archive-mode manifest that every
// table case can copy-and-mutate.
func validManifest() *Manifest {
	return &Manifest{
		Name:    "hello",
		Version: "1.0",
		Summary: "A tiny demonstration program",
		URL:     "https://example.org/packages/hello/hello-1.0.tar.gz",
		SHA256:  "731887527d1a72c57d1e64bad85cc341a4285354e773b2cd277420b744df2943",
		Archive: &Archive{Strip: 1},
	}
}

func TestManifest(t *testing.T) {
	tests := []struct {
		name       string
		mutate     func(m *Manifest)
		wantErr    bool
		wantErrSub string
	}{
		{
			name:   "valid archive manifest",
			mutate: func(m *Manifest) {},
		},
		{
			name: "missing version",
			mutate: func(m *Manifest) {
				m.Version = ""
			},
			wantErr:    true,
			wantErrSub: "missing version",
		},
		{
			name: "bad sha256",
			mutate: func(m *Manifest) {
				m.SHA256 = "zzz"
			},
			wantErr:    true,
			wantErrSub: "64 hex",
		},
		{
			name: "archive without url",
			mutate: func(m *Manifest) {
				m.URL = ""
			},
			wantErr:    true,
			wantErrSub: "archive mode requires a url",
		},
		{
			name: "remote url without sha256",
			mutate: func(m *Manifest) {
				m.SHA256 = ""
			},
			wantErr:    true,
			wantErrSub: "must declare sha256 for a remote url",
		},
		{
			name: "self dep",
			mutate: func(m *Manifest) {
				m.Deps = []string{"hello>=1.0"}
			},
			wantErr:    true,
			wantErrSub: "depends on itself",
		},
		{
			name: "dep with bad operator",
			mutate: func(m *Manifest) {
				m.Deps = []string{"pcre2<<10.42"}
			},
			wantErr:    true,
			wantErrSub: "bad dependency constraint",
		},
		{
			name: "dep without operator",
			mutate: func(m *Manifest) {
				m.Deps = []string{"pcre2 10.42"}
			},
			wantErr:    true,
			wantErrSub: "bad dependency constraint",
		},
		{
			name: "dotdot in files",
			mutate: func(m *Manifest) {
				m.Files = []string{"../evil"}
			},
			wantErr:    true,
			wantErrSub: "escapes the root",
		},
		{
			name: "empty files entry",
			mutate: func(m *Manifest) {
				m.Files = []string{""}
			},
			wantErr:    true,
			wantErrSub: "empty files entry",
		},
		{
			name: "duplicate files entry",
			mutate: func(m *Manifest) {
				m.Files = []string{"usr/bin/hello", "usr/bin/hello"}
			},
			wantErr:    true,
			wantErrSub: "twice",
		},
		{
			name: "negative strip",
			mutate: func(m *Manifest) {
				m.Archive = &Archive{Strip: -1}
			},
			wantErr:    true,
			wantErrSub: "non-negative integer",
		},
		{
			name: "leading dot name",
			mutate: func(m *Manifest) {
				m.Name = ".hidden"
			},
			wantErr:    true,
			wantErrSub: "invalid package name",
		},
		{
			name: "slash in name",
			mutate: func(m *Manifest) {
				m.Name = "a/b"
			},
			wantErr:    true,
			wantErrSub: "invalid package name",
		},
		{
			name: "unsafe local url",
			mutate: func(m *Manifest) {
				m.URL = "/tmp/foo bar"
				m.SHA256 = ""
			},
			wantErr:    true,
			wantErrSub: "looks unsafe",
		},
		{
			name: "valid deps with constraints",
			mutate: func(m *Manifest) {
				m.Deps = []string{"pcre2>=10.42", "libffi", "libz=1.2.13", "foo == 1.0"}
			},
		},
		{
			name: "local url without sha256 ok",
			mutate: func(m *Manifest) {
				m.URL = "/var/cache/zeta/hello-1.0.tar.gz"
				m.SHA256 = ""
			},
		},
		{
			name: "valid files entries cleaned",
			mutate: func(m *Manifest) {
				m.Files = []string{"usr/bin/hello", "/usr/share/doc/", "./etc/zeta"}
			},
		},
		{
			name: "empty summary ok",
			mutate: func(m *Manifest) {
				m.Summary = ""
			},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			m := validManifest()
			tt.mutate(m)
			err := m.Validate()
			if tt.wantErr {
				if err == nil {
					t.Fatalf("Validate() = nil, want error containing %q", tt.wantErrSub)
				}
				if tt.wantErrSub != "" && !strings.Contains(err.Error(), tt.wantErrSub) {
					t.Fatalf("Validate() error = %q, want it to contain %q", err, tt.wantErrSub)
				}
				return
			}
			if err != nil {
				t.Fatalf("Validate() = %v, want nil", err)
			}
		})
	}
}

func TestManifestSHA256Lowered(t *testing.T) {
	m := validManifest()
	m.SHA256 = strings.ToUpper(m.SHA256)
	if err := m.Validate(); err != nil {
		t.Fatalf("Validate() = %v, want nil (uppercase hex accepted)", err)
	}
	if m.SHA256 != strings.ToLower(m.SHA256) {
		t.Fatalf("SHA256 = %q, want it lowercased", m.SHA256)
	}
}

func TestManifestEmitFormat(t *testing.T) {
	m := &Manifest{
		Name:    "tool",
		Version: "2.0",
		Summary: "say \"hi\"\nnewline",
		URL:     "https://example.org/packages/tool/tool-2.0.tar.gz",
		SHA256:  "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
		Deps:    []string{"libz>=1.2.13", "pcre2"},
		Archive: &Archive{Strip: 1},
	}
	want := `return {
  name    = "tool",
  version = "2.0",
  summary = "say \"hi\"\nnewline",
  url     = "https://example.org/packages/tool/tool-2.0.tar.gz",
  sha256  = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
  deps    = { "libz>=1.2.13", "pcre2" },
  archive = { strip = 1 },
}
`
	got, err := m.Emit()
	if err != nil {
		t.Fatalf("Emit() error = %v", err)
	}
	if got != want {
		t.Fatalf("Emit() output mismatch:\n--- got ---\n%s\n--- want ---\n%s", got, want)
	}
}

func TestManifestEmitInvalid(t *testing.T) {
	m := validManifest()
	m.Version = ""
	if _, err := m.Emit(); err == nil {
		t.Fatal("Emit() = nil error, want validation error for missing version")
	}
}

func TestManifestGolden(t *testing.T) {
	m := &Manifest{
		Name:    "hello",
		Version: "1.0",
		Summary: "A tiny demonstration program",
		URL:     "https://example.org/packages/hello/hello-1.0.tar.gz",
		SHA256:  "731887527d1a72c57d1e64bad85cc341a4285354e773b2cd277420b744df2943",
		Deps:    []string{},
	}
	got, err := m.Emit()
	if err != nil {
		t.Fatalf("Emit() error = %v", err)
	}

	goldenPath := filepath.Join("..", "..", "testdata", "golden", "hello.package.lua")
	if os.Getenv("UPDATE_GOLDEN") == "1" {
		if err := os.MkdirAll(filepath.Dir(goldenPath), 0o755); err != nil {
			t.Fatalf("MkdirAll: %v", err)
		}
		if err := os.WriteFile(goldenPath, []byte(got), 0o644); err != nil {
			t.Fatalf("WriteFile golden: %v", err)
		}
		t.Logf("wrote golden %s", goldenPath)
		return
	}

	want, err := os.ReadFile(goldenPath)
	if err != nil {
		t.Fatalf("ReadFile golden %s: %v (run UPDATE_GOLDEN=1 to regenerate)", goldenPath, err)
	}
	if got != string(want) {
		t.Fatalf("Emit() does not match golden %s:\n--- got ---\n%s\n--- want ---\n%s", goldenPath, got, want)
	}
}