package etoro

import (
	"encoding/json"
	"fmt"
	"net/http"
	"time"
)

const instrumentsURL = "https://api.etoro.com/metadata/instruments"

// InstrumentTypeID connus sur eToro
const (
	TypeStock  = 5
	TypeETF    = 10
	TypeCrypto = 12
	TypeIndex  = 21
	TypeCFD    = 6
)

type Client struct {
	http *http.Client
}

type Instrument struct {
	InstrumentID          int    `json:"InstrumentID"`
	InstrumentDisplayName string `json:"InstrumentDisplayName"`
	SymbolFull            string `json:"SymbolFull"`
	InstrumentTypeID      int    `json:"InstrumentTypeID"`
	IsActive              bool   `json:"IsActive"`
	StockIndustryID       int    `json:"StockIndustryID"`
	StockExchangeID       int    `json:"StockExchangeID"`
}

func New() *Client {
	return &Client{
		http: &http.Client{Timeout: 30 * time.Second},
	}
}

// FetchStocks retourne tous les instruments de type Stock actifs sur eToro.
func (c *Client) FetchStocks() ([]Instrument, error) {
	all, err := c.fetchAll()
	if err != nil {
		return nil, err
	}

	var stocks []Instrument
	for _, inst := range all {
		if inst.IsActive && inst.InstrumentTypeID == TypeStock {
			stocks = append(stocks, inst)
		}
	}
	return stocks, nil
}

// FetchAll retourne tous les instruments (stocks + ETFs + crypto + indices).
func (c *Client) FetchAll() ([]Instrument, error) {
	return c.fetchAll()
}

func (c *Client) fetchAll() ([]Instrument, error) {
	req, err := http.NewRequest("GET", instrumentsURL, nil)
	if err != nil {
		return nil, err
	}

	// Headers qui imitent le client web eToro
	req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36")
	req.Header.Set("accounttype", "Demo")
	req.Header.Set("ApplicationIdentifier", "ReToro")
	req.Header.Set("Version", "1.211.0")
	req.Header.Set("Accept", "application/json")

	resp, err := c.http.Do(req)
	if err != nil {
		return nil, fmt.Errorf("etoro: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != 200 {
		return nil, fmt.Errorf("etoro: HTTP %d", resp.StatusCode)
	}

	var instruments []Instrument
	if err := json.NewDecoder(resp.Body).Decode(&instruments); err != nil {
		return nil, fmt.Errorf("etoro: parse error: %w", err)
	}

	if len(instruments) == 0 {
		return nil, fmt.Errorf("etoro: empty response — l'API a peut-être changé")
	}

	return instruments, nil
}