Add Conda package registry (#22262)

This PR adds a [Conda](https://conda.io/) package registry.

models/packages/conda/search.go

@@ -0,0 +1,63 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package conda
+
+import (
+	"context"
+	"strings"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/packages"
+	conda_module "code.gitea.io/gitea/modules/packages/conda"
+
+	"xorm.io/builder"
+)
+
+type FileSearchOptions struct {
+	OwnerID  int64
+	Channel  string
+	Subdir   string
+	Filename string
+}
+
+// SearchFiles gets all files matching the search options
+func SearchFiles(ctx context.Context, opts *FileSearchOptions) ([]*packages.PackageFile, error) {
+	var cond builder.Cond = builder.Eq{
+		"package.type":                packages.TypeConda,
+		"package.owner_id":            opts.OwnerID,
+		"package_version.is_internal": false,
+	}
+
+	if opts.Filename != "" {
+		cond = cond.And(builder.Eq{
+			"package_file.lower_name": strings.ToLower(opts.Filename),
+		})
+	}
+
+	var versionPropsCond builder.Cond = builder.Eq{
+		"package_property.ref_type": packages.PropertyTypePackage,
+		"package_property.name":     conda_module.PropertyChannel,
+		"package_property.value":    opts.Channel,
+	}
+
+	cond = cond.And(builder.In("package.id", builder.Select("package_property.ref_id").Where(versionPropsCond).From("package_property")))
+
+	var filePropsCond builder.Cond = builder.Eq{
+		"package_property.ref_type": packages.PropertyTypeFile,
+		"package_property.name":     conda_module.PropertySubdir,
+		"package_property.value":    opts.Subdir,
+	}
+
+	cond = cond.And(builder.In("package_file.id", builder.Select("package_property.ref_id").Where(filePropsCond).From("package_property")))
+
+	sess := db.GetEngine(ctx).
+		Select("package_file.*").
+		Table("package_file").
+		Join("INNER", "package_version", "package_version.id = package_file.version_id").
+		Join("INNER", "package", "package.id = package_version.package_id").
+		Where(cond)
+
+	pfs := make([]*packages.PackageFile, 0, 10)
+	return pfs, sess.Find(&pfs)
+}

models/packages/descriptor.go

@@ -13,6 +13,7 @@ import (
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/packages/composer"
 	"code.gitea.io/gitea/modules/packages/conan"
+	"code.gitea.io/gitea/modules/packages/conda"
 	"code.gitea.io/gitea/modules/packages/container"
 	"code.gitea.io/gitea/modules/packages/helm"
 	"code.gitea.io/gitea/modules/packages/maven"
@@ -132,6 +133,8 @@ func GetPackageDescriptor(ctx context.Context, pv *PackageVersion) (*PackageDesc
 		metadata = &composer.Metadata{}
 	case TypeConan:
 		metadata = &conan.Metadata{}
+	case TypeConda:
+		metadata = &conda.VersionMetadata{}
 	case TypeContainer:
 		metadata = &container.Metadata{}
 	case TypeGeneric:

models/packages/package.go

@@ -32,6 +32,7 @@ type Type string
 const (
 	TypeComposer  Type = "composer"
 	TypeConan     Type = "conan"
+	TypeConda     Type = "conda"
 	TypeContainer Type = "container"
 	TypeGeneric   Type = "generic"
 	TypeHelm      Type = "helm"
@@ -47,6 +48,7 @@ const (
 var TypeList = []Type{
 	TypeComposer,
 	TypeConan,
+	TypeConda,
 	TypeContainer,
 	TypeGeneric,
 	TypeHelm,
@@ -66,6 +68,8 @@ func (pt Type) Name() string {
 		return "Composer"
 	case TypeConan:
 		return "Conan"
+	case TypeConda:
+		return "Conda"
 	case TypeContainer:
 		return "Container"
 	case TypeGeneric:
@@ -97,6 +101,8 @@ func (pt Type) SVGName() string {
 		return "gitea-composer"
 	case TypeConan:
 		return "gitea-conan"
+	case TypeConda:
+		return "gitea-conda"
 	case TypeContainer:
 		return "octicon-container"
 	case TypeGeneric: