Add user/organization code search (#19977)

Fixes #19925 

Screenshots:

![attels](https://user-images.githubusercontent.com/165205/173864718-fe789429-55bc-4cad-808c-9f02f335cddf.png)

routers/web/user/code.go

@@ -0,0 +1,114 @@
+// Copyright 2022 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 user
+
+import (
+	"net/http"
+
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/modules/base"
+	"code.gitea.io/gitea/modules/context"
+	code_indexer "code.gitea.io/gitea/modules/indexer/code"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+const (
+	tplUserCode base.TplName = "user/code"
+)
+
+// CodeSearch render user/organization code search page
+func CodeSearch(ctx *context.Context) {
+	if !setting.Indexer.RepoIndexerEnabled {
+		ctx.Redirect(ctx.ContextUser.HomeLink())
+		return
+	}
+
+	ctx.Data["IsPackageEnabled"] = setting.Packages.Enabled
+	ctx.Data["IsRepoIndexerEnabled"] = setting.Indexer.RepoIndexerEnabled
+	ctx.Data["Title"] = ctx.Tr("code.title")
+	ctx.Data["ContextUser"] = ctx.ContextUser
+
+	language := ctx.FormTrim("l")
+	keyword := ctx.FormTrim("q")
+
+	queryType := ctx.FormTrim("t")
+	isMatch := queryType == "match"
+
+	ctx.Data["Keyword"] = keyword
+	ctx.Data["Language"] = language
+	ctx.Data["queryType"] = queryType
+	ctx.Data["IsCodePage"] = true
+
+	if keyword == "" {
+		ctx.HTML(http.StatusOK, tplUserCode)
+		return
+	}
+
+	var (
+		repoIDs []int64
+		err     error
+	)
+
+	page := ctx.FormInt("page")
+	if page <= 0 {
+		page = 1
+	}
+
+	repoIDs, err = repo_model.FindUserCodeAccessibleOwnerRepoIDs(ctx, ctx.ContextUser.ID, ctx.Doer)
+	if err != nil {
+		ctx.ServerError("FindUserCodeAccessibleOwnerRepoIDs", err)
+		return
+	}
+
+	var (
+		total                 int
+		searchResults         []*code_indexer.Result
+		searchResultLanguages []*code_indexer.SearchResultLanguages
+	)
+
+	if len(repoIDs) > 0 {
+		total, searchResults, searchResultLanguages, err = code_indexer.PerformSearch(ctx, repoIDs, language, keyword, page, setting.UI.RepoSearchPagingNum, isMatch)
+		if err != nil {
+			if code_indexer.IsAvailable() {
+				ctx.ServerError("SearchResults", err)
+				return
+			}
+			ctx.Data["CodeIndexerUnavailable"] = true
+		} else {
+			ctx.Data["CodeIndexerUnavailable"] = !code_indexer.IsAvailable()
+		}
+
+		loadRepoIDs := make([]int64, 0, len(searchResults))
+		for _, result := range searchResults {
+			var find bool
+			for _, id := range loadRepoIDs {
+				if id == result.RepoID {
+					find = true
+					break
+				}
+			}
+			if !find {
+				loadRepoIDs = append(loadRepoIDs, result.RepoID)
+			}
+		}
+
+		repoMaps, err := repo_model.GetRepositoriesMapByIDs(loadRepoIDs)
+		if err != nil {
+			ctx.ServerError("GetRepositoriesMapByIDs", err)
+			return
+		}
+
+		ctx.Data["RepoMaps"] = repoMaps
+	}
+	ctx.Data["SearchResults"] = searchResults
+	ctx.Data["SearchResultLanguages"] = searchResultLanguages
+
+	pager := context.NewPagination(total, setting.UI.RepoSearchPagingNum, page, 5)
+	pager.SetDefaultParams(ctx)
+	pager.AddParam(ctx, "l", "Language")
+	ctx.Data["Page"] = pager
+
+	ctx.HTML(http.StatusOK, tplUserCode)
+}