refactor(backend/models): use pgtype for nullable fields

`sortToSQL` and unimplemented `filterToSQL`

backend/db/db.go

@@ -1,49 +1,50 @@
-package db
-
-import (
-	"context"
-	"fmt"
-	"net/http"
-	"time"
-
-	"github.com/jackc/pgx/v5"
-	"github.com/jackc/pgx/v5/pgxpool"
-)
-
-var connPool *pgxpool.Pool
-
-func InitDB(connString string) error {
-	poolConfig, err := pgxpool.ParseConfig(connString)
-	if err != nil {
-		return fmt.Errorf("error while parsing connection string: %w", err)
-	}
-
-	poolConfig.MaxConns = 100
-	poolConfig.MinConns = 0
-	poolConfig.MaxConnLifetime = time.Hour
-	poolConfig.HealthCheckPeriod = 30 * time.Second
-
-	connPool, err = pgxpool.NewWithConfig(context.Background(), poolConfig)
-	if err != nil {
-		return fmt.Errorf("error while initializing DB connections pool: %w", err)
-	}
-	return nil
-}
-
-func transaction(ctx context.Context, handler func(pgx.Tx) (statusCode int, err error)) (statusCode int, err error) {
-	tx, err := connPool.Begin(ctx)
-	if err != nil {
-		statusCode = http.StatusInternalServerError
-		return
-	}
-	statusCode, err = handler(tx)
-	if err != nil {
-		tx.Rollback(ctx)
-		return
-	}
-	err = tx.Commit(ctx)
-	if err != nil {
-		statusCode = http.StatusInternalServerError
-	}
-	return
-}
+package db
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+var connPool *pgxpool.Pool
+
+func InitDB(connString string) error {
+	poolConfig, err := pgxpool.ParseConfig(connString)
+	if err != nil {
+		return fmt.Errorf("error while parsing connection string: %w", err)
+	}
+
+	poolConfig.MaxConns = 100
+	poolConfig.MinConns = 0
+	poolConfig.MaxConnLifetime = time.Hour
+	poolConfig.HealthCheckPeriod = 30 * time.Second
+
+	connPool, err = pgxpool.NewWithConfig(context.Background(), poolConfig)
+	if err != nil {
+		return fmt.Errorf("error while initializing DB connections pool: %w", err)
+	}
+	return nil
+}
+
+func transaction(handler func(context.Context, pgx.Tx) (statusCode int, err error)) (statusCode int, err error) {
+	ctx := context.Background()
+	tx, err := connPool.Begin(ctx)
+	if err != nil {
+		statusCode = http.StatusInternalServerError
+		return
+	}
+	statusCode, err = handler(ctx, tx)
+	if err != nil {
+		tx.Rollback(ctx)
+		return
+	}
+	err = tx.Commit(ctx)
+	if err != nil {
+		statusCode = http.StatusInternalServerError
+	}
+	return
+}

backend/db/utils.go

@@ -0,0 +1,53 @@
+package db
+
+import (
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+// Convert "filter" URL param to SQL "WHERE" condition
+func filterToSQL(filter string) (sql string, statusCode int, err error) {
+	// filterTokens := strings.Split(string(filter), ";")
+	sql = "(true)"
+	return
+}
+
+// Convert "sort" URL param to SQL "ORDER BY"
+func sortToSQL(sort string) (sql string, statusCode int, err error) {
+	if sort == "" {
+		return
+	}
+	sortOptions := strings.Split(sort, ",")
+	sql = " ORDER BY "
+	for i, sortOption := range sortOptions {
+		sortOrder := sortOption[:1]
+		sortColumn := sortOption[1:]
+		// parse sorting order marker
+		switch sortOrder {
+		case "+":
+			sortOrder = "ASC"
+		case "-":
+			sortOrder = "DESC"
+		default:
+			err = fmt.Errorf("invalid sorting order mark: %q", sortOrder)
+			statusCode = http.StatusBadRequest
+			return
+		}
+		// validate sorting column
+		var n int
+		n, err = strconv.Atoi(sortColumn)
+		if err != nil || n < 0 {
+			err = fmt.Errorf("invalid sorting column: %q", sortColumn)
+			statusCode = http.StatusBadRequest
+			return
+		}
+		// add sorting option to query
+		if i > 0 {
+			sql += ","
+		}
+		sql += fmt.Sprintf("%s %s NULLS LAST", sortColumn, sortOrder)
+	}
+	return
+}

backend/models/models.go

@@ -1,71 +1,75 @@
-package models
-
-import "time"
-
-type User struct {
-	Name    string `json:"name"`
-	IsAdmin bool   `json:"is_admin"`
-}
-
-type MIME struct {
-	Name      string `json:"name"`
-	Extension string `json:"extension"`
-}
-
-type Category struct {
-	ID        string    `json:"id"`
-	Name      string    `json:"name"`
-	Color     string    `json:"color"`
-	CreatedAt time.Time `json:"created_at"`
-	Creator   User      `json:"creator"`
-}
-
-type File struct {
-	ID        string    `json:"id"`
-	Name      string    `json:"name"`
-	MIME      MIME      `json:"mime"`
-	CreatedAt time.Time `json:"created_at"`
-	Creator   User      `json:"creator"`
-}
-
-type Tag struct {
-	ID        string    `json:"id"`
-	Name      string    `json:"name"`
-	Color     string    `json:"color"`
-	Category  Category  `json:"category"`
-	CreatedAt time.Time `json:"created_at"`
-	Creator   User      `json:"creator"`
-}
-
-type Autotag struct {
-	TriggerTag Tag  `json:"trigger_tag"`
-	AddTag     Tag  `json:"add_tag"`
-	IsActive   bool `json:"is_active"`
-}
-
-type Pool struct {
-	ID        string    `json:"id"`
-	Name      string    `json:"name"`
-	CreatedAt time.Time `json:"created_at"`
-	Creator   User      `json:"creator"`
-}
-
-type Session struct {
-	ID           int       `json:"id"`
-	UserAgent    string    `json:"user_agent"`
-	StartedAt    time.Time `json:"started_at"`
-	ExpiresAt    time.Time `json:"expires_at"`
-	LastActivity time.Time `json:"last_activity"`
-}
-
-type Pagination struct {
-	Total  int `json:"total"`
-	Offset int `json:"offset"`
-	Limit  int `json:"limit"`
-	Count  int `json:"count"`
-}
-
-type Slice[T any] struct {
-	Pagination Pagination `json:"pagination"`
-	Data       []T        `json:"data"`
-}
+package models
+
+import (
+	"time"
+
+	"github.com/jackc/pgx/v5/pgtype"
+)
+
+type User struct {
+	Name    string `json:"name"`
+	IsAdmin bool   `json:"is_admin"`
+}
+
+type MIME struct {
+	Name      string `json:"name"`
+	Extension string `json:"extension"`
+}
+
+type Category struct {
+	ID        string      `json:"id"`
+	Name      string      `json:"name"`
+	Color     pgtype.Text `json:"color"`
+	CreatedAt time.Time   `json:"created_at"`
+	Creator   User        `json:"creator"`
+}
+
+type File struct {
+	ID        string      `json:"id"`
+	Name      pgtype.Text `json:"name"`
+	MIME      MIME        `json:"mime"`
+	CreatedAt time.Time   `json:"created_at"`
+	Creator   User        `json:"creator"`
+}
+
+type Tag struct {
+	ID        string      `json:"id"`
+	Name      string      `json:"name"`
+	Color     pgtype.Text `json:"color"`
+	Category  Category    `json:"category"`
+	CreatedAt time.Time   `json:"created_at"`
+	Creator   User        `json:"creator"`
+}
+
+type Autotag struct {
+	TriggerTag Tag  `json:"trigger_tag"`
+	AddTag     Tag  `json:"add_tag"`
+	IsActive   bool `json:"is_active"`
+}
+
+type Pool struct {
+	ID        string    `json:"id"`
+	Name      string    `json:"name"`
+	CreatedAt time.Time `json:"created_at"`
+	Creator   User      `json:"creator"`
+}
+
+type Session struct {
+	ID           int       `json:"id"`
+	UserAgent    string    `json:"user_agent"`
+	StartedAt    time.Time `json:"started_at"`
+	ExpiresAt    time.Time `json:"expires_at"`
+	LastActivity time.Time `json:"last_activity"`
+}
+
+type Pagination struct {
+	Total  int `json:"total"`
+	Offset int `json:"offset"`
+	Limit  int `json:"limit"`
+	Count  int `json:"count"`
+}
+
+type Slice[T any] struct {
+	Pagination Pagination `json:"pagination"`
+	Data       []T        `json:"data"`
+}