ch9.2-9.3

cmd/api/helpers.go

@@ -6,9 +6,11 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/url"
 	"strconv"
 	"strings"
 
+	"gitea.local.lab/Lbenedar/greenlight/internal/validator"
 	"github.com/julienschmidt/httprouter"
 )
 
@@ -83,3 +85,38 @@ func (app *application) readJSON(w http.ResponseWriter, r *http.Request, dst any
 	}
 	return nil
 }
+
+func (app *application) readString(qs url.Values, key string, defaultValue string) string {
+	s := qs.Get(key)
+
+	if s == "" {
+		return defaultValue
+	}
+
+	return s
+}
+
+func (app *application) readCSV(qs url.Values, key string, defaultValue []string) []string {
+	csv := qs.Get(key)
+
+	if csv == "" {
+		return defaultValue
+	}
+
+	return strings.Split(csv, ",")
+}
+
+func (app *application) readInt(qs url.Values, key string, defaultValue int, v *validator.Validator) int {
+	s := qs.Get(key)
+
+	if s == "" {
+		return defaultValue
+	}
+
+	i, err := strconv.Atoi(s)
+	if err != nil {
+		v.AddError(key, "must be an integer value")
+		return defaultValue
+	}
+	return i
+}

cmd/api/movies.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"strconv"
 
 	"gitea.local.lab/Lbenedar/greenlight/internal/data"
 	"gitea.local.lab/Lbenedar/greenlight/internal/validator"
@@ -93,6 +94,13 @@ func (app *application) updateMovieHandler(w http.ResponseWriter, r *http.Reques
 		return
 	}
 
+	if r.Header.Get("X-Expected-Version") != "" {
+		if strconv.FormatInt(int64(movie.Version), 32) != r.Header.Get("X-Expected-Version") {
+			app.editConflictResponse(w, r)
+			return
+		}
+	}
+
 	var input struct {
 		Title   *string       `json:"title"`
 		Year    *int32        `json:"year"`
@@ -165,3 +173,39 @@ func (app *application) deleteMovieHandler(w http.ResponseWriter, r *http.Reques
 		app.serverErrorResponse(w, r, err)
 	}
 }
+
+func (app *application) listMoviesHandler(w http.ResponseWriter, r *http.Request) {
+	var input struct {
+		Title  string
+		Genres []string
+		data.Filters
+	}
+
+	v := validator.New()
+
+	qs := r.URL.Query()
+
+	input.Title = app.readString(qs, "title", "")
+	input.Genres = app.readCSV(qs, "genres", []string{})
+	input.Filters.Page = app.readInt(qs, "page", 1, v)
+	input.Filters.PageSize = app.readInt(qs, "page_size", 20, v)
+	input.Filters.Sort = app.readString(qs, "sort", "id")
+
+	input.Filters.SortSafelist = []string{"id", "title", "year", "runtime", "-id", "-title", "-year", "-runtime"}
+
+	if data.ValidateFilters(v, input.Filters); !v.Valid() {
+		app.failedValidationResponse(w, r, v.Errors)
+		return
+	}
+
+	movies, err := app.models.Movies.GetAll(input.Title, input.Genres, input.Filters)
+	if err != nil {
+		app.serverErrorResponse(w, r, err)
+		return
+	}
+
+	err = app.writeJSON(w, http.StatusOK, envelope{"movies": movies}, nil)
+	if err != nil {
+		app.serverErrorResponse(w, r, err)
+	}
+}

cmd/api/routes.go

@@ -13,6 +13,8 @@ func (app *application) routes() *httprouter.Router {
 	router.MethodNotAllowed = http.HandlerFunc(app.methodNotAllowedResponse)
 
 	router.HandlerFunc(http.MethodGet, "/v1/healthcheck", app.healthcheckHandler)
+
+	router.HandlerFunc(http.MethodGet, "/v1/movies", app.listMoviesHandler)
 	router.HandlerFunc(http.MethodPost, "/v1/movies", app.createMovieHandler)
 	router.HandlerFunc(http.MethodGet, "/v1/movies/:id", app.showMovieHandler)
 	router.HandlerFunc(http.MethodPatch, "/v1/movies/:id", app.updateMovieHandler)

internal/data/filters.go

@@ -0,0 +1,19 @@
+package data
+
+import "gitea.local.lab/Lbenedar/greenlight/internal/validator"
+
+type Filters struct {
+	Page         int
+	PageSize     int
+	Sort         string
+	SortSafelist []string
+}
+
+func ValidateFilters(v *validator.Validator, f Filters) {
+	v.Check(f.Page > 0, "page", "must be greater than zero")
+	v.Check(f.Page <= 10_000_000, "page", "must be a maximum of 10 million")
+	v.Check(f.PageSize > 0, "page_size", "must be greater than zero")
+	v.Check(f.PageSize <= 100, "page_size", "must be a maximum of 100")
+
+	v.Check(validator.PermittedValue(f.Sort, f.SortSafelist...), "sort", "invalid sort values")
+}

internal/data/models.go

@@ -16,6 +16,7 @@ type Models struct {
 		Get(id int64) (*Movie, error)
 		Update(movie *Movie) error
 		Delete(id int64) error
+		GetAll(title string, genres []string, filter Filters) ([]*Movie, error)
 	}
 }
 

internal/data/movies.go

@@ -134,6 +134,48 @@ func (m MovieModel) Delete(id int64) error {
 	return nil
 }
 
+func (m MovieModel) GetAll(title string, genres []string, filter Filters) ([]*Movie, error) {
+	query := `
+		SELECT id, created_at, title, year, runtime, genres, version
+		FROM movies
+		ORDER BY id`
+
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	rows, err := m.DB.QueryContext(ctx, query)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	movies := []*Movie{}
+
+	for rows.Next() {
+		var movie Movie
+
+		err := rows.Scan(
+			&movie.ID,
+			&movie.CreatedAt,
+			&movie.Title,
+			&movie.Year,
+			&movie.Runtime,
+			pq.Array(&movie.Genres),
+			&movie.Version,
+		)
+		if err != nil {
+			return nil, err
+		}
+		movies = append(movies, &movie)
+	}
+
+	if err = rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return movies, nil
+}
+
 type MockMovieModel struct{}
 
 func (m MockMovieModel) Insert(movie *Movie) error {
@@ -152,6 +194,10 @@ func (m MockMovieModel) Delete(id int64) error {
 	return nil
 }
 
+func (m MockMovieModel) GetAll(title string, genres []string, filter Filters) ([]*Movie, error) {
+	return nil, nil
+}
+
 func ValidateMovie(v *validator.Validator, movie *Movie) {
 	v.Check(movie.Title != "", "title", "must be provided")
 	v.Check(len(movie.Title) <= 500, "title", "must not be more than 500 bytes long")