main.go

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"regexp"
	"strconv"
)

// Movie is a struct
type Movie struct {
	ID        int     `json:"id"`
	Name      string  `json:"name"`
	FilmMaker string  `json:"filmMaker"`
	Rating    float32 `json:"rating"`
}

func findProduct(mid int) (int, error) {
	for i, p := range movies {
		if p.ID == mid {
			return i, nil
		}
	}
	return -1, fmt.Errorf("movie not Found")
}

func returnResponse(w http.ResponseWriter) {
	err := json.NewEncoder(w).Encode(movies)
	if err != nil {
		fmt.Println("There seems to be an error : ", err)
		return
	}
}

func returnError(w http.ResponseWriter, s string) {
	err := json.NewEncoder(w).Encode(s)
	if err != nil {
		fmt.Println("There seems to be an error : ", err)
		return
	}
}

func mainHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	if r.Method == http.MethodGet {
		fmt.Println("A GET request.")

		returnResponse(w) // Returns a json of all the Movies in the database
	}

	if r.Method == http.MethodPost {
		fmt.Println("A POST request.")
		var p Movie
		err := json.NewDecoder(r.Body).Decode(&p)
		if err != nil {
			returnError(w, "Couldn't decode your request body.")
			fmt.Println("There seems to be an error : ", err)
			return
		}
		p.ID = len(movies) + 1
		movies = append(movies, p)

		returnResponse(w)
	}

	if r.Method == http.MethodPut {
		fmt.Println("A PUT request.")

		reg := regexp.MustCompile(`/([0-9]+)`)
		g := reg.FindAllStringSubmatch(r.URL.Path, -1)
		strMid := g[0][1]
		mid, err := strconv.Atoi(strMid)
		if err != nil {
			returnError(w, "Couldn't decode the URI.")
			fmt.Println("Not a valid URI.")
			return
		}

		i, err := findProduct(mid)
		if err != nil {
			returnError(w, "Couldn't find the Movie id.")
			fmt.Println("There seems to be an error : ", err)
			return
		}

		var p Movie
		err = json.NewDecoder(r.Body).Decode(&p)
		if err != nil {
			returnError(w, "Couldn't decode your request body.")
			fmt.Println("There seems to be an error : ", err)
		}
		p.ID = mid
		movies[i] = p

		returnResponse(w)
	}

	if r.Method == http.MethodDelete {
		fmt.Println("A DELETE request.")

		reg := regexp.MustCompile(`/([0-9]+)`)
		g := reg.FindAllStringSubmatch(r.URL.Path, -1)
		strMid := g[0][1]
		mid, err := strconv.Atoi(strMid)
		if err != nil {
			returnError(w, "Couldn't decode the URI.")
			fmt.Println("Not a valid URI.")
			return
		}

		i, err := findProduct(mid)
		fmt.Println("i", i)
		fmt.Println(movies[i])
		if err != nil {
			returnError(w, "Couldn't find the Movie id.")
			fmt.Println("There seems to be an error : ", err)
			return
		}

		movies = append(movies[:i], movies[i+1:]...)

		returnResponse(w)

	}
}

func main() {
	http.HandleFunc("/", mainHandler)
	http.ListenAndServe(":8080", nil)
}

var movies = []Movie{
	Movie{1, "Chungking Express", "Wong Kar Wai", 9.0},
	Movie{ID: 2, Name: "Yi Yi", FilmMaker: "Edward Yang", Rating: 9.0},
	Movie{ID: 3, Name: "Memories of Murder", FilmMaker: "Bong Joon Ho", Rating: 8.9},
}