From 242fb3d36108ca2de56a3f9d0339afe3c3c9233b Mon Sep 17 00:00:00 2001
From: "Stanislav N. aka pztrn" <pztrn@pztrn.name>
Date: Mon, 30 Apr 2018 22:31:48 +0500
Subject: [PATCH] DDD (Domain Design) partially implemented, added comments
 everywhere.

---
 api/echo_logger.go                      |  2 ++
 api/exported.go                         |  2 ++
 api/http/exported.go                    | 12 ++----------
 api/http/index.go                       |  1 +
 api/json/exported.go                    |  1 +
 cmd/fastpastebin/fastpastebin.go        |  3 +++
 config/database.go                      |  1 +
 config/http.go                          |  1 +
 config/logging.go                       |  1 +
 config/struct.go                        |  1 +
 context/context.go                      | 17 ++++++++++++++++
 context/exported.go                     |  1 +
 database/database.go                    |  5 +++++
 database/exported.go                    |  1 +
 database/handler.go                     |  4 ++++
 database/interface/databaseinterface.go |  2 ++
 database/migrations/exported.go         |  3 +++
 api/http/paste.go => pastes/api_http.go | 15 ++++++++------
 pastes/exported.go                      | 26 +++++++++++++++++++++++++
 models/paste.go => pastes/model.go      |  3 ++-
 20 files changed, 85 insertions(+), 17 deletions(-)
 rename api/http/paste.go => pastes/api_http.go (93%)
 create mode 100644 pastes/exported.go
 rename models/paste.go => pastes/model.go (96%)

diff --git a/api/echo_logger.go b/api/echo_logger.go
index 3887692..e1f6c52 100644
--- a/api/echo_logger.go
+++ b/api/echo_logger.go
@@ -5,6 +5,7 @@ import (
 	"github.com/labstack/echo"
 )
 
+// Logs Echo requests.
 func echoReqLog(ec echo.Context, next echo.HandlerFunc) error {
 	c.Logger.Info().
 		Str("IP", ec.RealIP()).
@@ -18,6 +19,7 @@ func echoReqLog(ec echo.Context, next echo.HandlerFunc) error {
 	return nil
 }
 
+// Wrapper around previous function.
 func echoReqLogger() echo.MiddlewareFunc {
 	return func(next echo.HandlerFunc) echo.HandlerFunc {
 		return func(c echo.Context) error {
diff --git a/api/exported.go b/api/exported.go
index 24a5d94..054017b 100644
--- a/api/exported.go
+++ b/api/exported.go
@@ -16,10 +16,12 @@ var (
 	e *echo.Echo
 )
 
+// New initializes variables for api package.
 func New(cc *context.Context) {
 	c = cc
 }
 
+// InitializeAPI initializes HTTP API and starts web server.
 func InitializeAPI() {
 	c.Logger.Info().Msg("Initializing HTTP server...")
 
diff --git a/api/http/exported.go b/api/http/exported.go
index 29fa70c..c609874 100644
--- a/api/http/exported.go
+++ b/api/http/exported.go
@@ -13,6 +13,8 @@ var (
 	c *context.Context
 )
 
+// New initializes basic HTTP API, which shows only index page and serves
+// static files.
 func New(cc *context.Context) {
 	c = cc
 	c.Logger.Info().Msg("Initializing HTTP API...")
@@ -22,14 +24,4 @@ func New(cc *context.Context) {
 
 	// Index.
 	c.Echo.GET("/", indexGet)
-
-	// New paste.
-	c.Echo.POST("/paste/", pastePOST)
-
-	// Show paste.
-	c.Echo.GET("/paste/:id", pasteGET)
-
-	// Pastes list.
-	c.Echo.GET("/pastes/", pastesGET)
-	c.Echo.GET("/pastes/:page", pastesGET)
 }
diff --git a/api/http/index.go b/api/http/index.go
index 6aee24c..b36d6c0 100644
--- a/api/http/index.go
+++ b/api/http/index.go
@@ -11,6 +11,7 @@ import (
 	"github.com/labstack/echo"
 )
 
+// Index of this site.
 func indexGet(ec echo.Context) error {
 	html, err := static.ReadFile("index.html")
 	if err != nil {
diff --git a/api/json/exported.go b/api/json/exported.go
index 5b5bd29..ca6ee9e 100644
--- a/api/json/exported.go
+++ b/api/json/exported.go
@@ -9,6 +9,7 @@ var (
 	c *context.Context
 )
 
+// New initializes basic JSON API.
 func New(cc *context.Context) {
 	c = cc
 	c.Logger.Info().Msg("Initializing JSON API...")
diff --git a/cmd/fastpastebin/fastpastebin.go b/cmd/fastpastebin/fastpastebin.go
index d13527f..9b75ffb 100644
--- a/cmd/fastpastebin/fastpastebin.go
+++ b/cmd/fastpastebin/fastpastebin.go
@@ -11,6 +11,7 @@ import (
 	"github.com/pztrn/fastpastebin/context"
 	"github.com/pztrn/fastpastebin/database"
 	"github.com/pztrn/fastpastebin/database/migrations"
+	"github.com/pztrn/fastpastebin/pastes"
 )
 
 func main() {
@@ -34,6 +35,8 @@ func main() {
 	api.New(c)
 	api.InitializeAPI()
 
+	pastes.New(c)
+
 	// CTRL+C handler.
 	signalHandler := make(chan os.Signal, 1)
 	shutdownDone := make(chan bool, 1)
diff --git a/config/database.go b/config/database.go
index 7102678..43d6762 100644
--- a/config/database.go
+++ b/config/database.go
@@ -1,5 +1,6 @@
 package config
 
+// ConfigDatabase describes database configuration.
 type ConfigDatabase struct {
 	Address  string `yaml:"address"`
 	Port     string `yaml:"port"`
diff --git a/config/http.go b/config/http.go
index 8b3960d..24dd461 100644
--- a/config/http.go
+++ b/config/http.go
@@ -1,5 +1,6 @@
 package config
 
+// ConfigHTTP describes HTTP server configuration.
 type ConfigHTTP struct {
 	Address       string `yaml:"address"`
 	Port          string `yaml:"port"`
diff --git a/config/logging.go b/config/logging.go
index e4cfa5d..f82bc92 100644
--- a/config/logging.go
+++ b/config/logging.go
@@ -1,5 +1,6 @@
 package config
 
+// ConfigLogging describes logger configuration.
 type ConfigLogging struct {
 	LogToFile bool   `yaml:"log_to_file"`
 	FileName  string `yaml:"filename"`
diff --git a/config/struct.go b/config/struct.go
index 4c62116..be5f594 100644
--- a/config/struct.go
+++ b/config/struct.go
@@ -1,5 +1,6 @@
 package config
 
+// ConfigStruct describes whole configuration.
 type ConfigStruct struct {
 	Database ConfigDatabase `yaml:"database"`
 	Logging  ConfigLogging  `yaml:"logging"`
diff --git a/context/context.go b/context/context.go
index 1410cb8..ad94823 100644
--- a/context/context.go
+++ b/context/context.go
@@ -17,6 +17,10 @@ import (
 	"gopkg.in/yaml.v2"
 )
 
+// Context is a some sort of singleton. Basically it's a structure that
+// initialized once and then passed to all parts of application. It
+// contains everything every part of application need, like configuration
+// access, logger, etc.
 type Context struct {
 	Config   *config.ConfigStruct
 	Database databaseinterface.Interface
@@ -25,6 +29,7 @@ type Context struct {
 	Logger   zerolog.Logger
 }
 
+// Initialize initializes context.
 func (c *Context) Initialize() {
 	c.Logger = zerolog.New(zerolog.ConsoleWriter{Out: os.Stdout}).With().Timestamp().Caller().Logger()
 
@@ -39,11 +44,17 @@ func (c *Context) Initialize() {
 	})
 }
 
+// LoadConfiguration loads configuration and executes right after Flagger
+// have parsed CLI flags, because it depends on "-config" defined in
+// Initialize().
 func (c *Context) LoadConfiguration() {
 	c.Logger.Info().Msg("Loading configuration...")
 
 	var configPath = ""
 
+	// We're accepting configuration path from "-config" CLI parameter
+	// and FASTPASTEBIN_CONFIG environment variable. Later have higher
+	// weight and can override "-config" value.
 	configPathFromCLI, err := c.Flagger.GetStringValue("config")
 	configPathFromEnv, configPathFromEnvFound := os.LookupEnv("FASTPASTEBIN_CONFIG")
 
@@ -65,27 +76,33 @@ func (c *Context) LoadConfiguration() {
 
 	c.Config = &config.ConfigStruct{}
 
+	// Read configuration file.
 	fileData, err2 := ioutil.ReadFile(normalizedConfigPath)
 	if err2 != nil {
 		c.Logger.Panic().Msgf("Failed to read configuration file: %s", err2.Error())
 	}
 
+	// Parse it into structure.
 	err3 := yaml.Unmarshal(fileData, c.Config)
 	if err3 != nil {
 		c.Logger.Panic().Msgf("Failed to parse configuration file: %s", err3.Error())
 	}
 
+	// Yay! See what it gets!
 	c.Logger.Debug().Msgf("Parsed configuration: %+v", c.Config)
 }
 
+// RegisterDatabaseInterface registers database interface for later use.
 func (c *Context) RegisterDatabaseInterface(di databaseinterface.Interface) {
 	c.Database = di
 }
 
+// RegisterEcho registers Echo instance for later usage.
 func (c *Context) RegisterEcho(e *echo.Echo) {
 	c.Echo = e
 }
 
+// Shutdown shutdowns entire application.
 func (c *Context) Shutdown() {
 	c.Logger.Info().Msg("Shutting down Fast Pastebin...")
 }
diff --git a/context/exported.go b/context/exported.go
index 9847d19..e58d87b 100644
--- a/context/exported.go
+++ b/context/exported.go
@@ -1,5 +1,6 @@
 package context
 
+// New creates new context.
 func New() *Context {
 	return &Context{}
 }
diff --git a/database/database.go b/database/database.go
index 3b66975..d8254d4 100644
--- a/database/database.go
+++ b/database/database.go
@@ -9,17 +9,22 @@ import (
 	"github.com/jmoiron/sqlx"
 )
 
+// Database represents control structure for database connection.
 type Database struct {
 	db *sqlx.DB
 }
 
+// GetDatabaseConnection returns current database connection.
 func (db *Database) GetDatabaseConnection() *sqlx.DB {
 	return db.db
 }
 
+// Initialize initializes connection to database.
 func (db *Database) Initialize() {
 	c.Logger.Info().Msg("Initializing database connection...")
 
+	// There might be only user, without password. MySQL/MariaDB driver
+	// in DSN wants "user" or "user:password", "user:" is invalid.
 	var userpass = ""
 	if c.Config.Database.Password == "" {
 		userpass = c.Config.Database.Username
diff --git a/database/exported.go b/database/exported.go
index 318a3f5..e60579e 100644
--- a/database/exported.go
+++ b/database/exported.go
@@ -11,6 +11,7 @@ var (
 	d *Database
 )
 
+// New initializes database structure.
 func New(cc *context.Context) {
 	c = cc
 	d = &Database{}
diff --git a/database/handler.go b/database/handler.go
index d778b3c..a3be8ab 100644
--- a/database/handler.go
+++ b/database/handler.go
@@ -5,12 +5,16 @@ import (
 	"github.com/jmoiron/sqlx"
 )
 
+// Handler is an interfaceable structure that proxifies calls from anyone
+// to Database structure.
 type Handler struct{}
 
+// GetDatabaseConnection returns current database connection.
 func (dbh Handler) GetDatabaseConnection() *sqlx.DB {
 	return d.GetDatabaseConnection()
 }
 
+// Initialize initializes connection to database.
 func (dbh Handler) Initialize() {
 	d.Initialize()
 }
diff --git a/database/interface/databaseinterface.go b/database/interface/databaseinterface.go
index 3e39823..e96554c 100644
--- a/database/interface/databaseinterface.go
+++ b/database/interface/databaseinterface.go
@@ -5,6 +5,8 @@ import (
 	"github.com/jmoiron/sqlx"
 )
 
+// Interface represents database interface which is available to all
+// parts of application and registers with context.Context.
 type Interface interface {
 	GetDatabaseConnection() *sqlx.DB
 	Initialize()
diff --git a/database/migrations/exported.go b/database/migrations/exported.go
index 5d7cc1e..f575b8d 100644
--- a/database/migrations/exported.go
+++ b/database/migrations/exported.go
@@ -13,15 +13,18 @@ var (
 	c *context.Context
 )
 
+// New initializes migrations.
 func New(cc *context.Context) {
 	c = cc
 }
 
+// Migrate launching migrations.
 func Migrate() {
 	c.Logger.Info().Msg("Migrating database...")
 
 	goose.SetDialect("mysql")
 	goose.AddNamedMigration("1_initial.go", InitialUp, nil)
+	// Add new migrations BEFORE this message.
 
 	dbConn := c.Database.GetDatabaseConnection()
 	err := goose.Up(dbConn.DB, ".")
diff --git a/api/http/paste.go b/pastes/api_http.go
similarity index 93%
rename from api/http/paste.go
rename to pastes/api_http.go
index d6818ba..4ddeee0 100644
--- a/api/http/paste.go
+++ b/pastes/api_http.go
@@ -1,4 +1,4 @@
-package http
+package pastes
 
 import (
 	// stdlib
@@ -10,7 +10,6 @@ import (
 
 	// local
 	"github.com/pztrn/fastpastebin/api/http/static"
-	"github.com/pztrn/fastpastebin/models"
 
 	// other
 	"github.com/labstack/echo"
@@ -20,6 +19,7 @@ var (
 	regexInts = regexp.MustCompile("[0-9]+")
 )
 
+// GET for "/paste/PASTE_ID".
 func pasteGET(ec echo.Context) error {
 	errhtml, err := static.ReadFile("error.html")
 	if err != nil {
@@ -33,7 +33,7 @@ func pasteGET(ec echo.Context) error {
 	c.Logger.Debug().Msgf("Requesting paste #%+v", pasteID)
 
 	// Get paste.
-	paste := &models.Paste{ID: pasteID}
+	paste := &Paste{ID: pasteID}
 	err1 := paste.GetByID(c.Database.GetDatabaseConnection())
 	if err1 != nil {
 		c.Logger.Error().Msgf("Failed to get paste #%d from database: %s", pasteID, err1.Error())
@@ -50,6 +50,8 @@ func pasteGET(ec echo.Context) error {
 	return ec.HTML(http.StatusOK, string(pasteHTMLAsString))
 }
 
+// POST for "/paste/" which will create new paste and redirect to
+// "/pastes/CREATED_PASTE_ID".
 func pastePOST(ec echo.Context) error {
 	errhtml, err := static.ReadFile("error.html")
 	if err != nil {
@@ -68,7 +70,7 @@ func pastePOST(ec echo.Context) error {
 		return ec.HTML(http.StatusBadRequest, string(errhtml))
 	}
 
-	paste := &models.Paste{
+	paste := &Paste{
 		Title: params["paste-title"][0],
 		Data:  params["paste-contents"][0],
 	}
@@ -91,7 +93,7 @@ func pastePOST(ec echo.Context) error {
 	paste.KeepFor = keepFor
 
 	keepForUnitRaw := keepForUnitRegex.FindAllString(params["paste-keep-for"][0], 1)[0]
-	keepForUnit := models.PASTE_KEEPS_CORELLATION[keepForUnitRaw]
+	keepForUnit := PASTE_KEEPS_CORELLATION[keepForUnitRaw]
 	paste.KeepForUnitType = keepForUnit
 
 	id, err2 := paste.Save(c.Database.GetDatabaseConnection())
@@ -105,6 +107,7 @@ func pastePOST(ec echo.Context) error {
 	return ec.Redirect(http.StatusFound, "/paste/"+newPasteIDAsString)
 }
 
+// GET for "/pastes/", a list of publicly available pastes.
 func pastesGET(ec echo.Context) error {
 	pasteListHTML, err1 := static.ReadFile("pastelist_list.html")
 	if err1 != nil {
@@ -125,7 +128,7 @@ func pastesGET(ec echo.Context) error {
 
 	c.Logger.Debug().Msgf("Requested page #%d", page)
 
-	p := &models.Paste{}
+	p := &Paste{}
 	// Get pastes IDs.
 	pastes, err3 := p.GetPagedPastes(c.Database.GetDatabaseConnection(), page)
 	c.Logger.Debug().Msgf("Got %d pastes", len(pastes))
diff --git a/pastes/exported.go b/pastes/exported.go
new file mode 100644
index 0000000..3148a32
--- /dev/null
+++ b/pastes/exported.go
@@ -0,0 +1,26 @@
+package pastes
+
+import (
+	// local
+	"github.com/pztrn/fastpastebin/context"
+)
+
+var (
+	c *context.Context
+)
+
+// New initializes pastes package and adds neccessary HTTP and API
+// endpoints.
+func New(cc *context.Context) {
+	c = cc
+
+	// New paste.
+	c.Echo.POST("/paste/", pastePOST)
+
+	// Show paste.
+	c.Echo.GET("/paste/:id", pasteGET)
+
+	// Pastes list.
+	c.Echo.GET("/pastes/", pastesGET)
+	c.Echo.GET("/pastes/:page", pastesGET)
+}
diff --git a/models/paste.go b/pastes/model.go
similarity index 96%
rename from models/paste.go
rename to pastes/model.go
index ee8efc4..7871765 100644
--- a/models/paste.go
+++ b/pastes/model.go
@@ -1,4 +1,4 @@
-package models
+package pastes
 
 import (
 	// stdlib
@@ -24,6 +24,7 @@ var (
 	}
 )
 
+// Paste represents paste itself.
 type Paste struct {
 	ID              int        `db:"id"`
 	Title           string     `db:"title"`