package steam

import (
	"context"
	"errors"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
)

const validTicket = "140000008bc0a1f45fd4b4b7e0af2c4a01001001"

func stubValve(t *testing.T, status int, body string, inspect func(*http.Request)) WebAPIVerifier {
	t.Helper()
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if inspect != nil {
			inspect(r)
		}
		w.WriteHeader(status)
		_, _ = w.Write([]byte(body))
	}))
	t.Cleanup(server.Close)
	return WebAPIVerifier{PublisherKey: "publisher-key", AppID: 480, Endpoint: server.URL, HTTP: server.Client()}
}

func TestVerifyReturnsIdentityForAnAcceptedTicket(t *testing.T) {
	var seen *http.Request
	verifier := stubValve(t, http.StatusOK,
		`{"response":{"params":{"result":"OK","steamid":"76561198000000001","ownersteamid":"76561198000000001","vacbanned":false,"publisherbanned":false}}}`,
		func(r *http.Request) { seen = r })
	identity, err := verifier.Verify(context.Background(), validTicket)
	if err != nil {
		t.Fatalf("verify: %v", err)
	}
	if identity.SteamID != "76561198000000001" {
		t.Fatalf("identity = %+v", identity)
	}
	// The publisher key must be sent to Valve and nowhere else; assert it is
	// carried in the request rather than, say, logged or returned.
	if seen.URL.Query().Get("key") != "publisher-key" || seen.URL.Query().Get("appid") != "480" {
		t.Fatalf("request query = %s", seen.URL.RawQuery)
	}
	if seen.URL.Query().Get("ticket") != validTicket {
		t.Fatalf("ticket was not forwarded verbatim: %s", seen.URL.Query().Get("ticket"))
	}
}

func TestVerifyRejectsTicketsValveDoesNotAccept(t *testing.T) {
	for name, body := range map[string]string{
		"explicit failure": `{"response":{"params":{"result":"Failure","steamid":"76561198000000001"}}}`,
		"error object":     `{"response":{"error":{"errorcode":101,"errordesc":"Invalid ticket"}}}`,
		"empty response":   `{"response":{}}`,
		"no steam id":      `{"response":{"params":{"result":"OK"}}}`,
		"bogus steam id":   `{"response":{"params":{"result":"OK","steamid":"not-a-steam-id"}}}`,
	} {
		t.Run(name, func(t *testing.T) {
			verifier := stubValve(t, http.StatusOK, body, nil)
			if _, err := verifier.Verify(context.Background(), validTicket); !errors.Is(err, ErrTicketRejected) {
				t.Fatalf("err = %v, want ErrTicketRejected", err)
			}
		})
	}
}

func TestVerifyRejectsFamilySharedAndBannedAccounts(t *testing.T) {
	shared := stubValve(t, http.StatusOK,
		`{"response":{"params":{"result":"OK","steamid":"76561198000000002","ownersteamid":"76561198000000001"}}}`, nil)
	if _, err := shared.Verify(context.Background(), validTicket); !errors.Is(err, ErrTicketRejected) {
		t.Fatalf("family-shared copy accepted: %v", err)
	}

	banned := stubValve(t, http.StatusOK,
		`{"response":{"params":{"result":"OK","steamid":"76561198000000001","ownersteamid":"76561198000000001","vacbanned":true}}}`, nil)
	banned.RejectBanned = true
	if _, err := banned.Verify(context.Background(), validTicket); !errors.Is(err, ErrTicketRejected) {
		t.Fatalf("VAC-banned account accepted: %v", err)
	}
	banned.RejectBanned = false
	if _, err := banned.Verify(context.Background(), validTicket); err != nil {
		t.Fatalf("ban enforcement should be configurable: %v", err)
	}
}

// A Valve outage or a revoked publisher key must not read as "this player's
// ticket is bad", or a legitimate player is told to fix an account that is
// fine while the real fault goes unnoticed.
func TestVerifyDistinguishesOurFaultsFromBadTickets(t *testing.T) {
	for name, status := range map[string]int{
		"revoked publisher key": http.StatusForbidden,
		"unauthorized":          http.StatusUnauthorized,
		"valve error":           http.StatusInternalServerError,
		"valve gateway":         http.StatusBadGateway,
	} {
		t.Run(name, func(t *testing.T) {
			verifier := stubValve(t, status, `{}`, nil)
			if _, err := verifier.Verify(context.Background(), validTicket); !errors.Is(err, ErrUnavailable) {
				t.Fatalf("err = %v, want ErrUnavailable", err)
			}
		})
	}

	t.Run("malformed response", func(t *testing.T) {
		verifier := stubValve(t, http.StatusOK, `not json`, nil)
		if _, err := verifier.Verify(context.Background(), validTicket); !errors.Is(err, ErrUnavailable) {
			t.Fatalf("err = %v, want ErrUnavailable", err)
		}
	})
}

func TestVerifyRefusesMalformedTicketsWithoutCallingValve(t *testing.T) {
	called := false
	verifier := stubValve(t, http.StatusOK, `{}`, func(*http.Request) { called = true })
	for name, ticket := range map[string]string{
		"empty":      "",
		"whitespace": "   ",
		"not hex":    "zzzz-not-a-ticket",
		"oversized":  strings.Repeat("a", MaxTicketBytes+1),
	} {
		t.Run(name, func(t *testing.T) {
			if _, err := verifier.Verify(context.Background(), ticket); !errors.Is(err, ErrTicketRejected) {
				t.Fatalf("err = %v, want ErrTicketRejected", err)
			}
		})
	}
	if called {
		t.Fatal("a malformed ticket was forwarded to Valve")
	}
}

func TestVerifyIsUnavailableWithoutCredentials(t *testing.T) {
	for name, verifier := range map[string]WebAPIVerifier{
		"no key":    {AppID: 480},
		"no app id": {PublisherKey: "publisher-key"},
		"neither":   {},
	} {
		t.Run(name, func(t *testing.T) {
			if _, err := verifier.Verify(context.Background(), validTicket); !errors.Is(err, ErrUnavailable) {
				t.Fatalf("err = %v, want ErrUnavailable", err)
			}
		})
	}
}