1 files changed, 147 insertions, 0 deletions
diff --git a/modules/packages/composer/metadata.go b/modules/packages/composer/metadata.go
new file mode 100644
index 0000000000..797576b1e7
--- /dev/null
+++ b/modules/packages/composer/metadata.go
@@ -0,0 +1,147 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package composer
+
+import (
+	"archive/zip"
+	"errors"
+	"io"
+	"regexp"
+	"strings"
+
+	"code.gitea.io/gitea/modules/json"
+	"code.gitea.io/gitea/modules/validation"
+
+	"github.com/hashicorp/go-version"
+)
+
+// TypeProperty is the name of the property for Composer package types
+const TypeProperty = "composer.type"
+
+var (
+	// ErrMissingComposerFile indicates a missing composer.json file
+	ErrMissingComposerFile = errors.New("composer.json file is missing")
+	// ErrInvalidName indicates an invalid package name
+	ErrInvalidName = errors.New("package name is invalid")
+	// ErrInvalidVersion indicates an invalid package version
+	ErrInvalidVersion = errors.New("package version is invalid")
+)
+
+// Package represents a Composer package
+type Package struct {
+	Name     string
+	Version  string
+	Type     string
+	Metadata *Metadata
+}
+
+// Metadata represents the metadata of a Composer package
+type Metadata struct {
+	Description string                 `json:"description,omitempty"`
+	Keywords    []string               `json:"keywords,omitempty"`
+	Homepage    string                 `json:"homepage,omitempty"`
+	License     Licenses               `json:"license,omitempty"`
+	Authors     []Author               `json:"authors,omitempty"`
+	Autoload    map[string]interface{} `json:"autoload,omitempty"`
+	AutoloadDev map[string]interface{} `json:"autoload-dev,omitempty"`
+	Extra       map[string]interface{} `json:"extra,omitempty"`
+	Require     map[string]string      `json:"require,omitempty"`
+	RequireDev  map[string]string      `json:"require-dev,omitempty"`
+	Suggest     map[string]string      `json:"suggest,omitempty"`
+	Provide     map[string]string      `json:"provide,omitempty"`
+}
+
+// Licenses represents the licenses of a Composer package
+type Licenses []string
+
+// UnmarshalJSON reads from a string or array
+func (l *Licenses) UnmarshalJSON(data []byte) error {
+	switch data[0] {
+	case '"':
+		var value string
+		if err := json.Unmarshal(data, &value); err != nil {
+			return err
+		}
+		*l = Licenses{value}
+	case '[':
+		values := make([]string, 0, 5)
+		if err := json.Unmarshal(data, &values); err != nil {
+			return err
+		}
+		*l = Licenses(values)
+	}
+	return nil
+}
+
+// Author represents an author
+type Author struct {
+	Name     string `json:"name,omitempty"`
+	Email    string `json:"email,omitempty"`
+	Homepage string `json:"homepage,omitempty"`
+}
+
+var nameMatch = regexp.MustCompile(`\A[a-z0-9]([_\.-]?[a-z0-9]+)*/[a-z0-9](([_\.]?|-{0,2})[a-z0-9]+)*\z`)
+
+// ParsePackage parses the metadata of a Composer package file
+func ParsePackage(r io.ReaderAt, size int64) (*Package, error) {
+	archive, err := zip.NewReader(r, size)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, file := range archive.File {
+		if strings.Count(file.Name, "/") > 1 {
+			continue
+		}
+		if strings.HasSuffix(strings.ToLower(file.Name), "composer.json") {
+			f, err := archive.Open(file.Name)
+			if err != nil {
+				return nil, err
+			}
+			defer f.Close()
+
+			return ParseComposerFile(f)
+		}
+	}
+	return nil, ErrMissingComposerFile
+}
+
+// ParseComposerFile parses a composer.json file to retrieve the metadata of a Composer package
+func ParseComposerFile(r io.Reader) (*Package, error) {
+	var cj struct {
+		Name    string `json:"name"`
+		Version string `json:"version"`
+		Type    string `json:"type"`
+		Metadata
+	}
+	if err := json.NewDecoder(r).Decode(&cj); err != nil {
+		return nil, err
+	}
+
+	if !nameMatch.MatchString(cj.Name) {
+		return nil, ErrInvalidName
+	}
+
+	if cj.Version != "" {
+		if _, err := version.NewSemver(cj.Version); err != nil {
+			return nil, ErrInvalidVersion
+		}
+	}
+
+	if !validation.IsValidURL(cj.Homepage) {
+		cj.Homepage = ""
+	}
+
+	if cj.Type == "" {
+		cj.Type = "library"
+	}
+
+	return &Package{
+		Name:     cj.Name,
+		Version:  cj.Version,
+		Type:     cj.Type,
+		Metadata: &cj.Metadata,
+	}, nil
+}