package storage

import (
	"encoding/json"
	"errors"
	"fmt"
	"github.com/eslider/superherohub/pkg/deesee"
	"os"
	"strings"
)

// Json simple JSON memory storage.
type Json struct {
	path string              // Path to json file
	list []*deesee.Superhero // List of loaded superheroes
}

// NewJson Json storage.
func NewJson(path string) (d *Json, err error) {
	d = &Json{
		path: path,
	}
	err = d.Load(path)
	return
}

// Load superheroes from JSON file.
func (s *Json) Load(path string) error {
	f, err := os.OpenFile(path, os.O_RDONLY, 0644)
	if err != nil {
		return fmt.Errorf("unable to read f: %w", err)
	}

	return json.NewDecoder(f).Decode(&s.list)
}

// List superheros
func (s *Json) List() []*deesee.Superhero {
	return s.list
}

// Put superhero.
func (s *Json) Put(hero *deesee.Superhero) (err error) {
	// Check if superhero superpower is acceptable
	if !hero.IsAcceptable() {
		return errors.New(fmt.Sprintf("Hero power is not acceptable: %s", hero.Name))
	}

	// Prevent to store duplicate superheroes
	if deesee.FindByName(s.list, strings.TrimSpace(hero.Name)) != nil {
		return errors.New(fmt.Sprintf("Hero already exists: %s", hero.Name))
	}

	s.list = append(s.list, hero)
	return
}

// Persist superheroes to JSON file.
func (s *Json) Persist() error {
	f, err := os.OpenFile(s.path, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)
	if err != nil {
		return fmt.Errorf("unable to write file: %w", err)
	}
	return json.NewEncoder(f).Encode(s.list)
}