[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/license.go

@@ -0,0 +1,107 @@
+package pluginapi
+
+import (
+	"github.com/mattermost/mattermost/server/public/model"
+)
+
+const (
+	e10          = "E10"
+	e20          = "E20"
+	professional = "professional"
+	enterprise   = "enterprise"
+)
+
+// IsEnterpriseLicensedOrDevelopment returns true when the server is licensed with any Mattermost
+// Enterprise License, or has `EnableDeveloper` and `EnableTesting` configuration settings
+// enabled signaling a non-production, developer mode.
+func IsEnterpriseLicensedOrDevelopment(config *model.Config, license *model.License) bool {
+	if license != nil {
+		return true
+	}
+
+	return IsConfiguredForDevelopment(config)
+}
+
+// isValidSkuShortName returns whether the SKU short name is one of the known strings;
+// namely: E10 or professional, or E20 or enterprise
+func isValidSkuShortName(license *model.License) bool {
+	if license == nil {
+		return false
+	}
+
+	switch license.SkuShortName {
+	case e10, e20, professional, enterprise:
+		return true
+	default:
+		return false
+	}
+}
+
+// IsE10LicensedOrDevelopment returns true when the server is at least licensed with a legacy Mattermost
+// Enterprise E10 License or a Mattermost Professional License, or has `EnableDeveloper` and
+// `EnableTesting` configuration settings enabled, signaling a non-production, developer mode.
+func IsE10LicensedOrDevelopment(config *model.Config, license *model.License) bool {
+	if license != nil &&
+		(license.SkuShortName == e10 || license.SkuShortName == professional ||
+			license.SkuShortName == e20 || license.SkuShortName == enterprise) {
+		return true
+	}
+
+	if !isValidSkuShortName(license) {
+		// As a fallback for licenses whose SKU short name is unknown, make a best effort to try
+		// and use the presence of a known E10/Professional feature as a check to determine licensing.
+		if license != nil &&
+			license.Features != nil &&
+			license.Features.LDAP != nil &&
+			*license.Features.LDAP {
+			return true
+		}
+	}
+
+	return IsConfiguredForDevelopment(config)
+}
+
+// IsE20LicensedOrDevelopment returns true when the server is licensed with a legacy Mattermost
+// Enterprise E20 License or a Mattermost Enterprise License, or has `EnableDeveloper` and
+// `EnableTesting` configuration settings enabled, signaling a non-production, developer mode.
+func IsE20LicensedOrDevelopment(config *model.Config, license *model.License) bool {
+	if license != nil && (license.SkuShortName == e20 || license.SkuShortName == enterprise) {
+		return true
+	}
+
+	if !isValidSkuShortName(license) {
+		// As a fallback for licenses whose SKU short name is unknown, make a best effort to try
+		// and use the presence of a known E20/Enterprise feature as a check to determine licensing.
+		if license != nil &&
+			license.Features != nil &&
+			license.Features.FutureFeatures != nil &&
+			*license.Features.FutureFeatures {
+			return true
+		}
+	}
+
+	return IsConfiguredForDevelopment(config)
+}
+
+// IsConfiguredForDevelopment returns true when the server has `EnableDeveloper` and `EnableTesting`
+// configuration settings enabled, signaling a non-production, developer mode.
+func IsConfiguredForDevelopment(config *model.Config) bool {
+	if config != nil &&
+		config.ServiceSettings.EnableTesting != nil &&
+		*config.ServiceSettings.EnableTesting &&
+		config.ServiceSettings.EnableDeveloper != nil &&
+		*config.ServiceSettings.EnableDeveloper {
+		return true
+	}
+
+	return false
+}
+
+// IsCloud returns true when the server is on cloud, and false otherwise.
+func IsCloud(license *model.License) bool {
+	if license == nil || license.Features == nil || license.Features.Cloud == nil {
+		return false
+	}
+
+	return *license.Features.Cloud
+}