[MM-53968] Includes mattermost-plugin-api into the mono repo (#24235)

Include https://github.com/mattermost/mattermost-plugin-api into the mono repo

Co-authored-by: Jesse Hallam <jesse.hallam@gmail.com>
Co-authored-by: Michael Kochell <mjkochell@gmail.com>
Co-authored-by: Alejandro García Montoro <alejandro.garciamontoro@gmail.com>
Co-authored-by: Ben Schumacher <ben.schumacher@mattermost.com>
Co-authored-by: Alex Dovenmuehle <alex.dovenmuehle@mattermost.com>
Co-authored-by: Michael Kochell <6913320+mickmister@users.noreply.github.com>
Co-authored-by: Christopher Poile <cpoile@gmail.com>
Co-authored-by: İlker Göktuğ Öztürk <ilkergoktugozturk@gmail.com>
Co-authored-by: Shota Gvinepadze <wineson@gmail.com>
Co-authored-by: Ali Farooq <ali.farooq0@pm.me>
Co-authored-by: Maria A Nunez <maria.nunez@mattermost.com>
Co-authored-by: Daniel Espino García <larkox@gmail.com>
Co-authored-by: Christopher Speller <crspeller@gmail.com>
Co-authored-by: Alex Dovenmuehle <adovenmuehle@gmail.com>
Co-authored-by: Szymon Gibała <szymongib@gmail.com>
Co-authored-by: Lev <1187448+levb@users.noreply.github.com>
Co-authored-by: Jason Frerich <jason.frerich@mattermost.com>
Co-authored-by: Agniva De Sarker <agnivade@yahoo.co.in>
Co-authored-by: Artur M. Wolff <artur.m.wolff@gmail.com>
Co-authored-by: Madhav Hugar <16546715+madhavhugar@users.noreply.github.com>
Co-authored-by: Joe <security.joe@pm.me>
Co-authored-by: Ibrahim Serdar Acikgoz <serdaracikgoz86@gmail.com>
Co-authored-by: José Peso <trilopin@users.noreply.github.com>

server/public/pluginapi/experimental/common/kvstore.go

@@ -0,0 +1,21 @@
+package common
+
+import (
+	"errors"
+	"time"
+
+	"github.com/mattermost/mattermost/server/public/pluginapi"
+)
+
+var ErrNotFound = errors.New("not found")
+
+type KVStore interface {
+	Set(key string, value interface{}, options ...pluginapi.KVSetOption) (bool, error)
+	SetWithExpiry(key string, value interface{}, ttl time.Duration) error
+	CompareAndSet(key string, oldValue, value interface{}) (bool, error)
+	CompareAndDelete(key string, oldValue interface{}) (bool, error)
+	Get(key string, o interface{}) error
+	Delete(key string) error
+	DeleteAll() error
+	ListKeys(page, count int, options ...pluginapi.ListKeysOption) ([]string, error)
+}

server/public/pluginapi/experimental/common/logapi.go

@@ -0,0 +1,8 @@
+package common
+
+type LogAPI interface {
+	LogError(message string, keyValuePairs ...interface{})
+	LogWarn(message string, keyValuePairs ...interface{})
+	LogInfo(message string, keyValuePairs ...interface{})
+	LogDebug(message string, keyValuePairs ...interface{})
+}

server/public/pluginapi/experimental/common/markdown.go

@@ -0,0 +1,22 @@
+// Copyright (c) 2019-present Mattermost, Inc. All Rights Reserved.
+// See License for license information.
+
+package common
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+func JSON(ref interface{}) string {
+	bb, _ := json.MarshalIndent(ref, "", "  ")
+	return string(bb)
+}
+
+func CodeBlock(in string) string {
+	return fmt.Sprintf("\n```\n%s\n```\n", in)
+}
+
+func JSONBlock(ref interface{}) string {
+	return fmt.Sprintf("\n```json\n%s\n```\n", JSON(ref))
+}

server/public/pluginapi/experimental/common/slack_attachments.go

@@ -0,0 +1,24 @@
+package common
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/mattermost/mattermost/server/public/model"
+)
+
+func SlackAttachmentError(w http.ResponseWriter, err error) {
+	response := model.PostActionIntegrationResponse{
+		EphemeralText: "Error:" + err.Error(),
+	}
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(response)
+}
+
+func DialogError(w http.ResponseWriter, err error) {
+	response := model.SubmitDialogResponse{
+		Error: err.Error(),
+	}
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(response)
+}

server/public/pluginapi/experimental/common/url.go

@@ -0,0 +1,28 @@
+package common
+
+import (
+	"net/url"
+	"strings"
+
+	"github.com/mattermost/mattermost/server/public/pluginapi"
+)
+
+// GetPluginURL returns a url like siteURL/plugins/pluginID based on the information from the client.
+// If any error happens in the process, a empty string is returned.
+func GetPluginURL(client *pluginapi.Client) string {
+	mattermostSiteURL := client.Configuration.GetConfig().ServiceSettings.SiteURL
+	if mattermostSiteURL == nil {
+		return ""
+	}
+	_, err := url.Parse(*mattermostSiteURL)
+	if err != nil {
+		return ""
+	}
+	manifest, err := client.System.GetManifest()
+	if err != nil {
+		return ""
+	}
+
+	pluginURLPath := "/plugins/" + manifest.Id
+	return strings.TrimRight(*mattermostSiteURL, "/") + pluginURLPath
+}