feat: add initial project code

Add the initial code for the PokeDex project. For now the code can list
the next and previous 20 location areas within the Pokemon world.

.forgejo/workflows/workflow.yaml

@@ -22,5 +22,5 @@ jobs:
       with:
         target: test
       env:
-        PROJECT_TEST_VERBOSE: "1"
-        PROJECT_TEST_COVER: "1"
+        POKEDEX_TEST_VERBOSE: "1"
+        POKEDEX_TEST_COVER: "1"

.gitignore

@@ -1,2 +1 @@
-/__build/*
-!__build/.gitkeep
+pokedex

go.mod

@@ -0,0 +1,3 @@
+module codeflow.dananglin.me.uk/apollo/pokedex
+
+go 1.23.0

magefiles/go.mod

@@ -0,0 +1,5 @@
+module codeflow.dananglin.me.uk/apollo/pokedex/magefiles
+
+go 1.23.0
+
+require github.com/magefile/mage v1.15.0

magefiles/go.sum

@@ -0,0 +1,2 @@
+github.com/magefile/mage v1.15.0 h1:BvGheCMAsG3bWUDbZ8AyXXpCNwU9u5CB6sM+HNb9HYg=
+github.com/magefile/mage v1.15.0/go.mod h1:z5UZb/iS3GoOSn0JgWuiw7dxlurVYTu+/jHXqQg881A=

magefiles/mage.go

@@ -14,23 +14,23 @@ import (
 )
 
 const (
-	app                  = "binary"
+	app                  = "pokedex"
 	defaultInstallPrefix = "/usr/local"
-	envInstallPrefix     = "PROJECT_INSTALL_PREFIX"
-	envTestVerbose       = "PROJECT_TEST_VERBOSE"
-	envTestCover         = "PROJECT_TEST_COVER"
-	envBuildRebuildAll   = "PROJECT_BUILD_REBUILD_ALL"
-	envBuildVerbose      = "PROJECT_BUILD_VERBOSE"
+	envInstallPrefix     = "POKEDEX_INSTALL_PREFIX"
+	envTestVerbose       = "POKEDEX_TEST_VERBOSE"
+	envTestCover         = "POKEDEX_TEST_COVER"
+	envBuildRebuildAll   = "POKEDEX_BUILD_REBUILD_ALL"
+	envBuildVerbose      = "POKEDEX_BUILD_VERBOSE"
 )
 
 var (
 	Default = Build
-	binary  = "./__build/" + app
+	binary  = app
 )
 
 // Test run the go tests.
-// To enable verbose mode set PROJECT_TEST_VERBOSE=1.
-// To enable coverage mode set PROJECT_TEST_COVER=1.
+// To enable verbose mode set POKEDEX_TEST_VERBOSE=1.
+// To enable coverage mode set POKEDEX_TEST_COVER=1.
 func Test() error {
 	goTest := sh.RunCmd("go", "test")
 
@@ -53,8 +53,8 @@ func Lint() error {
 }
 
 // Build build the executable.
-// To rebuild packages that are already up-to-date set PROJECT_BUILD_REBUILD_ALL=1
-// To enable verbose mode set PROJECT_BUILD_VERBOSE=1
+// To rebuild packages that are already up-to-date set POKEDEX_BUILD_REBUILD_ALL=1
+// To enable verbose mode set POKEDEX_BUILD_VERBOSE=1
 func Build() error {
 	main := "main.go"
 	flags := ldflags()

main.go

@@ -1,24 +1,174 @@
 package main
 
 import (
+	"bufio"
+	"context"
+	"encoding/json"
 	"fmt"
+	"maps"
+	"net/http"
 	"os"
+	"slices"
+	"time"
 )
 
-var (
-	binaryVersion string
-	buildTime     string
-	goVersion     string
-	gitCommit     string
+const (
+	baseURL              string = "https://pokeapi.co/api/v2"
+	locationAreaEndpoint string = "/location-area"
 )
 
+type State struct {
+	Previous *string
+	Next     *string
+}
+
+var state State
+
+type command struct {
+	name        string
+	description string
+	callback    func() error
+}
+
 func main() {
-	if err := run(); err != nil {
+	run()
+}
+
+func run() {
+	fmt.Print("pokedex > ")
+
+	scanner := bufio.NewScanner(os.Stdin)
+
+	for scanner.Scan() {
+		command := scanner.Text()
+
+		cmdMap := getCommandMap()
+		if _, ok := cmdMap[command]; !ok {
+			fmt.Println("ERROR: Unrecognised command.")
+
+			fmt.Print("\npokedex > ")
+
+			continue
+		}
+
+		if err := cmdMap[command].callback(); err != nil {
 			fmt.Printf("ERROR: %v.\n", err)
-		os.Exit(1)
+		}
+
+		fmt.Print("pokedex > ")
 	}
 }
 
-func run() error {
+func getCommandMap() map[string]command {
+	return map[string]command{
+		"exit": {
+			name:        "exit",
+			description: "Exit the Pokedex",
+			callback:    commandExit,
+		},
+		"help": {
+			name:        "help",
+			description: "Displays a help message",
+			callback:    commandHelp,
+		},
+		"map": {
+			name:        "map",
+			description: "Displays the next 20 locations in the Pokemon world",
+			callback:    commandMap,
+		},
+		"mapb": {
+			name:        "map back",
+			description: "Displays the previous 20 locations in the Pokemon world",
+			callback:    commandMapB,
+		},
+	}
+}
+
+func commandHelp() error {
+	cmdMap := getCommandMap()
+
+	keys := []string{}
+
+	for key := range maps.All(cmdMap) {
+		keys = append(keys, key)
+	}
+
+	slices.Sort(keys)
+
+	fmt.Printf("\nWelcome to the Pokedex!\nUsage:\n")
+
+	for _, key := range slices.All(keys) {
+		fmt.Printf("\n%s: %s", key, cmdMap[key].description)
+	}
+
+	fmt.Println("\n")
+
+	return nil
+}
+
+func commandExit() error {
+	os.Exit(0)
+
+	return nil
+}
+
+func commandMap() error {
+	url := state.Next
+	if url == nil {
+		url = new(string)
+		*url = baseURL + locationAreaEndpoint
+	}
+
+	return printMap(*url)
+}
+
+func commandMapB() error {
+	url := state.Previous
+	if url == nil {
+		return fmt.Errorf("no previous locations available")
+	}
+
+	return printMap(*url)
+}
+
+func printMap(url string) error {
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return fmt.Errorf("error creating the HTTP request: %w", err)
+	}
+
+	client := http.Client{}
+
+	resp, err := client.Do(request)
+	if err != nil {
+		return fmt.Errorf("error getting the response from the server: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode >= 400 {
+		return fmt.Errorf(
+			"received a bad status from %s: (%d) %s",
+			url,
+			resp.StatusCode,
+			resp.Status,
+		)
+	}
+
+	var result NamedAPIResourceList
+
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return fmt.Errorf("unable to decode the JSON response: %w", err)
+	}
+
+	state.Next = result.Next
+	state.Previous = result.Previous
+
+	for _, location := range slices.All(result.Results) {
+		fmt.Println(location.Name)
+	}
+
 	return nil
 }

types.go

@@ -0,0 +1,59 @@
+package main
+
+// LocationArea is a section of areas such as floors in a building or a cave.
+type LocationArea struct {
+	ID                   int                   `json:"id"`
+	Name                 string                `json:"name"`
+	GameIndex            int                   `json:"game_index"`
+	EncounterMethodRates []EncounterMethodRate `json:"encounter_method_rates"`
+	Location             NamedAPIResource      `json:"location"`
+	Names                []Name                `json:"names"`
+	PokemonEncounters    []PokemonEncounter    `json:"pokemon_encounters"`
+}
+
+type EncounterMethodRate struct {
+	EncounterMethod NamedAPIResource        `json:"encounter_method"`
+	VersionDetails  EncounterVersionDetails `json:"version_details"`
+}
+
+type EncounterVersionDetails struct {
+	Rate    int              `json:"rate"`
+	Version NamedAPIResource `json:"version"`
+}
+
+type Name struct {
+	Name     string           `json:"name"`
+	Language NamedAPIResource `json:"language"`
+}
+
+// PokemonEncounter is details of a possible Pokemon encounter.
+type PokemonEncounter struct {
+	Pokemon        NamedAPIResource          `json:"pokemon"`
+	VersionDetails []VersionEncounterDetails `json:"version_details"`
+}
+
+type VersionEncounterDetails struct {
+	Version          NamedAPIResource `json:"version"`
+	MaxChance        int              `json:"max_chance"`
+	EncounterDetails []Encounter      `json:"encounter_details"`
+}
+
+type Encounter struct {
+	MinLevel        int                `json:"min_level"`
+	MaxLevel        int                `json:"max_level"`
+	ConditionValues []NamedAPIResource `json:"condition_values"`
+	Chance          int                `json:"chance"`
+	Method          NamedAPIResource   `json:"method"`
+}
+
+type NamedAPIResourceList struct {
+	Count    int                `json:"count"`
+	Next     *string             `json:"next"`
+	Previous *string             `json:"previous"`
+	Results  []NamedAPIResource `json:"results"`
+}
+
+type NamedAPIResource struct {
+	Name string `json:"name"`
+	URL  string `json:"url"`
+}