package api

import (
	"encoding/json"
	"io"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	"github.com/ponzischeme89/memby/server/internal/config"
	"github.com/ponzischeme89/memby/server/internal/store"
)

func testServer(cfg config.Config) *Server {
	return New(cfg, Deps{Log: slog.New(slog.NewTextHandler(io.Discard, nil))})
}

func TestMaintenanceGatePassesTrafficWhenOnline(t *testing.T) {
	server := testServer(config.Config{})
	var reached bool
	handler := server.maintenanceGate(http.HandlerFunc(func(http.ResponseWriter, *http.Request) {
		reached = true
	}))

	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/v1/home", nil))

	if !reached || rec.Code != http.StatusOK {
		t.Fatalf("request should have passed through, got %d", rec.Code)
	}
}

func TestMaintenanceGateBlocksWithTheOperatorsMessage(t *testing.T) {
	server := testServer(config.Config{})
	server.maintenance.set(store.Maintenance{Enabled: true, Message: "Back at 9pm"})

	handler := server.maintenanceGate(http.HandlerFunc(func(http.ResponseWriter, *http.Request) {
		t.Fatal("handler must not run while offline")
	}))

	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/v1/home", nil))

	if rec.Code != http.StatusServiceUnavailable {
		t.Fatalf("expected 503, got %d", rec.Code)
	}
	if rec.Header().Get("Retry-After") == "" {
		t.Fatal("expected a Retry-After header")
	}

	var body map[string]any
	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
		t.Fatalf("body: %v", err)
	}
	// The TV keys off `maintenance` to tell "we turned it off" from "the network died".
	if body["maintenance"] != true {
		t.Fatalf("expected maintenance:true, got %v", body)
	}
	if body["message"] != "Back at 9pm" {
		t.Fatalf("operator message not surfaced: %v", body["message"])
	}
}

func TestMaintenanceGateFallsBackToADefaultMessage(t *testing.T) {
	server := testServer(config.Config{})
	server.maintenance.set(store.Maintenance{Enabled: true})

	rec := httptest.NewRecorder()
	server.maintenanceGate(http.NotFoundHandler()).
		ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/v1/home", nil))

	var body map[string]any
	_ = json.Unmarshal(rec.Body.Bytes(), &body)
	if body["message"] != store.DefaultMaintenanceMessage {
		t.Fatalf("expected the default message, got %v", body["message"])
	}
}

func TestHealthAndAdminStayReachableDuringMaintenance(t *testing.T) {
	// Health checks and the admin page sit outside the gate on purpose: they are what
	// you need most while the app is deliberately down.
	server := testServer(config.Config{AdminToken: "secret"})
	server.maintenance.set(store.Maintenance{Enabled: true})

	rec := httptest.NewRecorder()
	server.handleHealth(rec, httptest.NewRequest(http.MethodGet, "/healthz", nil))
	if rec.Code != http.StatusOK {
		t.Fatalf("healthz should stay 200 during maintenance, got %d", rec.Code)
	}

	rec = httptest.NewRecorder()
	server.adminRoutes().ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/admin/", nil))
	if rec.Code != http.StatusOK {
		t.Fatalf("admin page should stay reachable, got %d", rec.Code)
	}
}

func TestServiceStatusReportsMaintenanceOutsideTheGate(t *testing.T) {
	server := testServer(config.Config{})
	server.maintenance.set(store.Maintenance{Enabled: true, Message: "Back after dinner"})

	rec := httptest.NewRecorder()
	server.handleServiceStatus(
		rec,
		httptest.NewRequest(http.MethodGet, "/v1/status", nil),
		store.Session{},
	)
	if rec.Code != http.StatusOK {
		t.Fatalf("status endpoint returned %d", rec.Code)
	}
	var body map[string]any
	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
		t.Fatal(err)
	}
	if body["maintenance"] != true || body["message"] != "Back after dinner" {
		t.Fatalf("unexpected status response: %v", body)
	}
}

func TestServiceStatusMakesProtocolMismatchVisible(t *testing.T) {
	server := testServer(config.Config{})
	req := httptest.NewRequest(http.MethodGet, "/v1/status", nil)
	req.Header.Set("X-Memby-Version", "0.9.1")
	req.Header.Set("X-Memby-Protocol", "99")
	rec := httptest.NewRecorder()

	server.handleServiceStatus(rec, req, store.Session{})

	var body map[string]any
	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
		t.Fatal(err)
	}
	if body["compatible"] != false || body["compatibilityMessage"] == "" {
		t.Fatalf("mismatch was not explicit: %v", body)
	}
	if body["clientVersion"] != "0.9.1" || body["serverProtocol"] != float64(membyProtocolVersion) {
		t.Fatalf("version diagnostics missing: %v", body)
	}
}

func TestServiceStatusAcceptsCurrentProtocol(t *testing.T) {
	server := testServer(config.Config{})
	req := httptest.NewRequest(http.MethodGet, "/v1/status", nil)
	req.Header.Set("X-Memby-Protocol", "1")
	rec := httptest.NewRecorder()
	server.handleServiceStatus(rec, req, store.Session{})

	var body map[string]any
	_ = json.Unmarshal(rec.Body.Bytes(), &body)
	if body["compatible"] != true || body["compatibilityMessage"] != "" {
		t.Fatalf("current protocol should be compatible: %v", body)
	}
}

func TestAdminIsDisabledWithoutAToken(t *testing.T) {
	server := testServer(config.Config{})

	for _, path := range []string{"/admin/", "/admin/api/status"} {
		rec := httptest.NewRecorder()
		server.adminRoutes().ServeHTTP(rec, httptest.NewRequest(http.MethodGet, path, nil))
		if rec.Code != http.StatusNotFound {
			t.Fatalf("%s should 404 when no admin token is configured, got %d", path, rec.Code)
		}
	}
}

func TestAdminAuthRejectsAWrongToken(t *testing.T) {
	server := testServer(config.Config{AdminToken: "secret"})
	handler := server.adminAuth(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusOK)
	})

	cases := map[string]string{
		"missing": "",
		"wrong":   "Bearer nope",
		"prefix":  "Bearer secretish",
	}
	for name, header := range cases {
		req := httptest.NewRequest(http.MethodGet, "/admin/api/status", nil)
		if header != "" {
			req.Header.Set("Authorization", header)
		}
		rec := httptest.NewRecorder()
		handler.ServeHTTP(rec, req)
		if rec.Code != http.StatusUnauthorized {
			t.Fatalf("%s token should be rejected, got %d", name, rec.Code)
		}
	}

	req := httptest.NewRequest(http.MethodGet, "/admin/api/status", nil)
	req.Header.Set("Authorization", "Bearer secret")
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("the correct token should be accepted, got %d", rec.Code)
	}
}

func TestAdminPageEstablishesPersistentCookie(t *testing.T) {
	server := testServer(config.Config{AdminToken: "secret"})
	req := httptest.NewRequest(http.MethodGet, "https://memby.local/admin/", nil)
	rec := httptest.NewRecorder()

	server.handleAdminPage(rec, req)

	result := rec.Result()
	cookies := result.Cookies()
	if len(cookies) != 1 {
		t.Fatalf("expected one admin cookie, got %d", len(cookies))
	}
	cookie := cookies[0]
	if cookie.Name != adminCookieName || cookie.Value != "secret" {
		t.Fatalf("unexpected admin cookie: %#v", cookie)
	}
	if !cookie.HttpOnly || !cookie.Secure || cookie.SameSite != http.SameSiteStrictMode {
		t.Fatalf("admin cookie is not hardened: %#v", cookie)
	}
	if cookie.MaxAge <= 0 || cookie.Path != "/admin" {
		t.Fatalf("admin cookie is not persistent or scoped: %#v", cookie)
	}
}

func TestAdminAuthAcceptsPersistentCookie(t *testing.T) {
	server := testServer(config.Config{AdminToken: "secret"})
	handler := server.adminAuth(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusOK)
	})
	req := httptest.NewRequest(http.MethodGet, "/admin/api/status", nil)
	req.AddCookie(&http.Cookie{Name: adminCookieName, Value: "secret"})
	rec := httptest.NewRecorder()

	handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("the admin cookie should be accepted, got %d", rec.Code)
	}
}

func TestToRowEventValidatesAndClamps(t *testing.T) {
	now := time.Date(2026, 7, 27, 12, 0, 0, 0, time.UTC)

	t.Run("rejects unknown event kinds", func(t *testing.T) {
		if _, ok := toRowEvent(rowEventPayload{RowID: "r", Event: "scrolled"}, "u", now); ok {
			t.Fatal("unknown event kind should be dropped")
		}
	})

	t.Run("rejects events with no row", func(t *testing.T) {
		if _, ok := toRowEvent(rowEventPayload{Event: "focus"}, "u", now); ok {
			t.Fatal("an event with no row id should be dropped")
		}
	})

	t.Run("clamps implausible dwell", func(t *testing.T) {
		event, ok := toRowEvent(rowEventPayload{RowID: "r", Event: "focus", DwellMs: 99 * 60 * 60 * 1000}, "u", now)
		if !ok {
			t.Fatal("event should be accepted")
		}
		if event.DwellMs != maxDwellMs {
			t.Fatalf("dwell = %d, want clamped to %d", event.DwellMs, maxDwellMs)
		}

		event, _ = toRowEvent(rowEventPayload{RowID: "r", Event: "focus", DwellMs: -5}, "u", now)
		if event.DwellMs != 0 {
			t.Fatalf("negative dwell should floor at 0, got %d", event.DwellMs)
		}
	})

	t.Run("ignores a device clock that is wildly wrong", func(t *testing.T) {
		event, _ := toRowEvent(
			rowEventPayload{RowID: "r", Event: "impression", OccurredAt: "1970-01-01T00:00:00Z"}, "u", now)
		if !event.OccurredAt.Equal(now) {
			t.Fatalf("expected the server clock to win, got %v", event.OccurredAt)
		}
	})

	t.Run("accepts a plausible device timestamp", func(t *testing.T) {
		earlier := now.Add(-30 * time.Second).Format(time.RFC3339)
		event, _ := toRowEvent(rowEventPayload{RowID: "r", Event: "select", OccurredAt: earlier}, "u", now)
		if event.OccurredAt.Equal(now) {
			t.Fatal("a recent device timestamp should be kept")
		}
	})

	t.Run("stamps the session's user", func(t *testing.T) {
		event, _ := toRowEvent(rowEventPayload{RowID: "r", Event: "focus"}, "user-9", now)
		if event.UserID != "user-9" {
			t.Fatalf("user should come from the session, got %q", event.UserID)
		}
	})
}