package auth

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"strconv"
	"strings"
	"time"
)

// GateStatus is what SE's server-status endpoint says about the login gate.
type GateStatus struct {
	Up      bool
	Message string // localized notice published while the gate is closed, lines joined with \n
	News    string // optional news lines published alongside the notice
}

// CheckGate asks frontier.ffxiv.com whether the game servers are accepting
// logins. FFXIVQuickLauncher does this before login and again right before it
// launches the game; we use its richer endpoint (gate_status.json, which
// carries a localized maintenance message) for both moments. lang is one of
// the client language codes: "ja", "en", "de" or "fr".
func CheckGate(lang string) (*GateStatus, error) {
	u := "https://frontier.ffxiv.com/worldStatus/gate_status.json?lang=" + lang + "&_=" + strconv.FormatInt(time.Now().UnixMilli(), 10)
	req, err := http.NewRequest(http.MethodGet, u, nil)
	if err != nil {
		return nil, err
	}
	setCommonHeaders(req, frontierReferer())

	resp, err := httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("gate status: %w", err)
	}
	defer resp.Body.Close()
	body, _ := io.ReadAll(io.LimitReader(resp.Body, 1<<20))
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("gate status: HTTP %d", resp.StatusCode)
	}
	return parseGateStatus(body)
}

// SE answers {"status":1} while the gate is open — a number, not a boolean.
// Json.NET coerces that for QL; we accept both shapes here.
type rawGate struct {
	Status  any      `json:"status"`
	Message []string `json:"message"`
	News    []string `json:"news"`
}

func parseGateStatus(body []byte) (*GateStatus, error) {
	var r rawGate
	if err := json.Unmarshal(body, &r); err != nil {
		return nil, fmt.Errorf("gate status: %w", err)
	}
	gs := &GateStatus{
		Message: strings.Join(r.Message, "\n"),
		News:    strings.Join(r.News, "\n"),
	}
	switch s := r.Status.(type) {
	case bool:
		gs.Up = s
	case float64:
		gs.Up = s != 0
	default:
		return nil, fmt.Errorf("gate status: unrecognized status value %v", r.Status)
	}
	return gs, nil
}