internal: move packages under this directory (#5836)

* Rename pkg -> internal

* Rename routes -> route

* Move route -> internal/route

* Rename models -> db

* Move db -> internal/db

* Fix route2 -> route

* Move cmd -> internal/cmd

* Bump version

internal/context/api.go

@@ -0,0 +1,107 @@
+// Copyright 2016 The Gogs 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 context
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/unknwon/paginater"
+	log "gopkg.in/clog.v1"
+	"gopkg.in/macaron.v1"
+
+	"gogs.io/gogs/internal/setting"
+)
+
+type APIContext struct {
+	*Context // TODO: Reduce to only needed fields instead of full shadow
+
+	// Base URL for the version of API endpoints, e.g. https://try.gogs.io/api/v1
+	BaseURL string
+
+	Org *APIOrganization
+}
+
+// FIXME: move this constant to github.com/gogs/go-gogs-client
+const DocURL = "https://github.com/gogs/docs-api"
+
+// Error responses error message to client with given message.
+// If status is 500, also it prints error to log.
+func (c *APIContext) Error(status int, title string, obj interface{}) {
+	var message string
+	if err, ok := obj.(error); ok {
+		message = err.Error()
+	} else {
+		message = obj.(string)
+	}
+
+	if status == http.StatusInternalServerError {
+		log.Error(3, "%s: %s", title, message)
+	}
+
+	c.JSON(status, map[string]string{
+		"message": message,
+		"url":     DocURL,
+	})
+}
+
+// NoContent renders the 204 response.
+func (c *APIContext) NoContent() {
+	c.Status(http.StatusNoContent)
+}
+
+// NotFound renders the 404 response.
+func (c *APIContext) NotFound() {
+	c.Status(http.StatusNotFound)
+}
+
+// ServerError renders the 500 response.
+func (c *APIContext) ServerError(title string, err error) {
+	c.Error(http.StatusInternalServerError, title, err)
+}
+
+// NotFoundOrServerError use error check function to determine if the error
+// is about not found. It responses with 404 status code for not found error,
+// or error context description for logging purpose of 500 server error.
+func (c *APIContext) NotFoundOrServerError(title string, errck func(error) bool, err error) {
+	if errck(err) {
+		c.NotFound()
+		return
+	}
+	c.ServerError(title, err)
+}
+
+// SetLinkHeader sets pagination link header by given total number and page size.
+func (c *APIContext) SetLinkHeader(total, pageSize int) {
+	page := paginater.New(total, pageSize, c.QueryInt("page"), 0)
+	links := make([]string, 0, 4)
+	if page.HasNext() {
+		links = append(links, fmt.Sprintf("<%s%s?page=%d>; rel=\"next\"", setting.AppURL, c.Req.URL.Path[1:], page.Next()))
+	}
+	if !page.IsLast() {
+		links = append(links, fmt.Sprintf("<%s%s?page=%d>; rel=\"last\"", setting.AppURL, c.Req.URL.Path[1:], page.TotalPages()))
+	}
+	if !page.IsFirst() {
+		links = append(links, fmt.Sprintf("<%s%s?page=1>; rel=\"first\"", setting.AppURL, c.Req.URL.Path[1:]))
+	}
+	if page.HasPrevious() {
+		links = append(links, fmt.Sprintf("<%s%s?page=%d>; rel=\"prev\"", setting.AppURL, c.Req.URL.Path[1:], page.Previous()))
+	}
+
+	if len(links) > 0 {
+		c.Header().Set("Link", strings.Join(links, ","))
+	}
+}
+
+func APIContexter() macaron.Handler {
+	return func(ctx *Context) {
+		c := &APIContext{
+			Context: ctx,
+			BaseURL: setting.AppURL + "api/v1",
+		}
+		ctx.Map(c)
+	}
+}