package main

import (
	"bufio"
	"errors"
	"fmt"
	"github.com/rdarius/boot-dev-pokedex/pokeapi"
	"os"
	"strings"
	"time"
)

type config struct {
	pokeapiClient    pokeapi.Client
	nextLocationsURL *string
	prevLocationsURL *string
}

type cliCommand struct {
	name        string
	description string
	callback    func(*config) error
}

var commands map[string]cliCommand

func main() {

	pokeClient := pokeapi.NewClient(5*time.Second, time.Minute*5)
	cfg := &config{
		pokeapiClient: pokeClient,
	}

	commands = map[string]cliCommand{
		"exit": {
			name:        "exit",
			description: "Exit the Pokedex",
			callback:    commandExit,
		},
		"help": {
			name:        "help",
			description: "Display a help message",
			callback:    printHelpMessage,
		},
		"map": {
			name:        "map",
			description: "Get the next page of locations",
			callback:    commandMapf,
		},
		"mapb": {
			name:        "mapb",
			description: "Get the previous page of locations",
			callback:    commandMapb,
		},
	}
	for {
		// read user input
		input := bufio.NewScanner(os.Stdin)
		fmt.Print("Pokedex > ")
		for input.Scan() {
			word := input.Text()
			cleanedWord := cleanInput(word)
			command := cleanedWord[0]

			//check if command is in commands map
			cmd, ok := commands[command]
			if ok {
				err := cmd.callback(cfg)
				if err != nil {
					fmt.Println(err)
				}
			} else {
				fmt.Println("Unknown command")
			}
			fmt.Print("Pokedex > ")
		}
	}
}

func commandExit(*config) error {
	fmt.Println("Closing the Pokedex... Goodbye!")
	os.Exit(0)
	return nil
}

func cleanInput(text string) []string {
	output := strings.ToLower(text)
	words := strings.Fields(output)
	return words
}

func printHelpMessage(*config) error {
	fmt.Print("Welcome to the Pokedex!\nUsage:\n\n")
	for _, v := range commands {
		fmt.Printf("%s: %s\n", v.name, v.description)
	}
	return nil
}

func commandMapf(cfg *config) error {
	locationsResp, err := cfg.pokeapiClient.ListLocations(cfg.nextLocationsURL)
	if err != nil {
		return err
	}

	cfg.nextLocationsURL = locationsResp.Next
	cfg.prevLocationsURL = locationsResp.Previous

	for _, loc := range locationsResp.Results {
		fmt.Println(loc.Name)
	}
	return nil
}

func commandMapb(cfg *config) error {
	if cfg.prevLocationsURL == nil {
		return errors.New("you're on the first page")
	}

	locationResp, err := cfg.pokeapiClient.ListLocations(cfg.prevLocationsURL)
	if err != nil {
		return err
	}

	cfg.nextLocationsURL = locationResp.Next
	cfg.prevLocationsURL = locationResp.Previous

	for _, loc := range locationResp.Results {
		fmt.Println(loc.Name)
	}
	return nil
}