package httpapi

import (
	"context"
	"encoding/json"
	"errors"
	"io"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"net/netip"
	"testing"

	"botpontos/internal/config"
	"botpontos/internal/domain"
)

type fakePinger struct{ err error }

func (f fakePinger) Ping(context.Context) error { return f.err }

var discard = slog.New(slog.NewTextHandler(io.Discard, nil))

func serve(t *testing.T, db Pinger, method, path string) *httptest.ResponseRecorder {
	t.Helper()
	rec := httptest.NewRecorder()
	NewHandler(db, nil, config.Config{}, discard).ServeHTTP(rec, httptest.NewRequest(method, path, nil))
	return rec
}

func TestLive(t *testing.T) {
	rec := serve(t, fakePinger{err: errors.New("banco fora")}, http.MethodGet, "/api/v1/health/live")

	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, esperado 200 (live não depende do banco)", rec.Code)
	}
	if rec.Header().Get("X-Request-ID") == "" {
		t.Error("X-Request-ID ausente")
	}
}

func TestReadyWithDatabase(t *testing.T) {
	rec := serve(t, fakePinger{}, http.MethodGet, "/api/v1/health/ready")
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, esperado 200", rec.Code)
	}
}

func TestReadyWithoutDatabase(t *testing.T) {
	rec := serve(t, fakePinger{err: errors.New("conexão recusada")}, http.MethodGet, "/api/v1/health/ready")
	if rec.Code != http.StatusServiceUnavailable {
		t.Fatalf("status = %d, esperado 503", rec.Code)
	}
	assertProblem(t, rec, "DB_UNAVAILABLE")
}

func TestUnknownRoute(t *testing.T) {
	rec := serve(t, fakePinger{}, http.MethodGet, "/api/v1/nao-existe")
	if rec.Code != http.StatusNotFound {
		t.Fatalf("status = %d, esperado 404", rec.Code)
	}
	assertProblem(t, rec, "NOT_FOUND")
}

func TestProtectedRouteWithoutSession(t *testing.T) {
	rec := serve(t, fakePinger{}, http.MethodGet, "/api/v1/users")
	if rec.Code != http.StatusUnauthorized {
		t.Fatalf("status = %d, esperado 401", rec.Code)
	}
	assertProblem(t, rec, "UNAUTHENTICATED")
}

func TestWriteErrorValidation(t *testing.T) {
	a := &API{log: discard}
	rec := httptest.NewRecorder()
	a.writeError(rec, domain.ValidationErrors{{Field: "lunch_minutes", Message: "inválido"}})
	if rec.Code != http.StatusUnprocessableEntity {
		t.Fatalf("status = %d, esperado 422", rec.Code)
	}
	var body struct {
		Errors []domain.ValidationError `json:"errors"`
	}
	_ = json.NewDecoder(rec.Body).Decode(&body)
	if len(body.Errors) != 1 || body.Errors[0].Field != "lunch_minutes" {
		t.Errorf("erros de campo inesperados: %+v", body.Errors)
	}
}

func TestSameOrigin(t *testing.T) {
	a := &API{cfg: config.Config{Web: config.Web{PublicURL: "https://botpontos.lan"}}}
	cases := []struct {
		origin, referer string
		want            bool
	}{
		{"https://botpontos.lan", "", true},
		{"https://evil.example", "", false},
		{"", "https://botpontos.lan/usuarios", true},
		{"", "https://botpontos.lan.evil.example/", false},
		{"", "", false},
	}
	for _, c := range cases {
		r := httptest.NewRequest(http.MethodPost, "/api/v1/users/1/activate", nil)
		if c.origin != "" {
			r.Header.Set("Origin", c.origin)
		}
		if c.referer != "" {
			r.Header.Set("Referer", c.referer)
		}
		if got := a.sameOrigin(r); got != c.want {
			t.Errorf("origin=%q referer=%q: %v, esperado %v", c.origin, c.referer, got, c.want)
		}
	}
}

func TestClientIP(t *testing.T) {
	a := &API{cfg: config.Config{Web: config.Web{TrustedProxies: []netip.Prefix{
		netip.MustParsePrefix("172.16.0.0/12"),
		netip.MustParsePrefix("192.168.18.10/32"), // NPM
	}}}}

	r := httptest.NewRequest(http.MethodGet, "/", nil)
	r.RemoteAddr = "172.18.0.5:41000" // container web
	// Cliente forjou um IP à esquerda; o NPM acrescentou o IP real; o Next acrescentou o NPM.
	r.Header.Set("X-Forwarded-For", "1.2.3.4, 192.168.18.50, 192.168.18.10")
	if got := a.clientIP(r); got != "192.168.18.50" {
		t.Errorf("clientIP = %s, esperado 192.168.18.50", got)
	}

	direct := httptest.NewRequest(http.MethodGet, "/", nil)
	direct.RemoteAddr = "10.9.9.9:1234"
	direct.Header.Set("X-Forwarded-For", "1.2.3.4")
	if got := a.clientIP(direct); got != "10.9.9.9" {
		t.Errorf("origem não confiável deveria ignorar X-Forwarded-For, veio %s", got)
	}
}

func assertProblem(t *testing.T, rec *httptest.ResponseRecorder, code string) {
	t.Helper()
	if ct := rec.Header().Get("Content-Type"); ct != "application/problem+json; charset=utf-8" {
		t.Errorf("Content-Type = %q", ct)
	}
	var body struct {
		Status int    `json:"status"`
		Code   string `json:"code"`
	}
	if err := json.NewDecoder(rec.Body).Decode(&body); err != nil {
		t.Fatalf("corpo inválido: %v", err)
	}
	if body.Code != code || body.Status != rec.Code {
		t.Errorf("problem = %+v, esperado code=%s status=%d", body, code, rec.Code)
	}
}