package api_test

import (
	"bytes"
	"encoding/json"
	"io"
	"net/http"
	"testing"
)

// The whole point of #4: two teams sharing one server must not see each other's
// work. These tests build two of them and check the boundary from both sides.

type teamFixture struct {
	id   int64
	key  string // integration key: how alerts get in
	call func(method, path string, body any) *http.Response
}

// newTeam creates a team with its own member, integration key and API key. The
// admin does the creating, as an install's first user would.
func newTeam(t *testing.T, s *ts, name string) teamFixture {
	t.Helper()

	var team struct {
		ID int64 `json:"id"`
	}
	decode(t, s.req(t, http.MethodPost, "/api/teams", map[string]string{"name": name}), &team)

	var integration struct {
		Key string `json:"key"`
		URL string `json:"url"`
	}
	decode(t, s.req(t, http.MethodPost, "/api/teams/"+id64(team.ID)+"/integrations",
		map[string]string{"name": name + " alertmanager"}), &integration)
	if integration.Key == "" {
		t.Fatalf("%s: integration key was not returned", name)
	}

	// A member of this team and no other.
	var user struct {
		ID int64 `json:"id"`
	}
	decode(t, s.req(t, http.MethodPost, "/api/users",
		map[string]string{"username": name + "-user", "email": name + "@test.com"}), &user)

	resp := s.req(t, http.MethodPost, "/api/teams/"+id64(team.ID)+"/members",
		map[string]any{"user_id": user.ID, "role": "owner"})
	resp.Body.Close()
	if resp.StatusCode != http.StatusNoContent {
		t.Fatalf("%s: add member: %d", name, resp.StatusCode)
	}

	var key struct {
		Key string `json:"key"`
	}
	decode(t, s.req(t, http.MethodPost, "/api/users/"+id64(user.ID)+"/api-keys",
		map[string]string{"name": "test"}), &key)

	return teamFixture{
		id:  team.ID,
		key: integration.Key,
		call: func(method, path string, body any) *http.Response {
			t.Helper()
			var r io.Reader
			if body != nil {
				data, _ := json.Marshal(body)
				r = bytes.NewReader(data)
			}
			req, _ := http.NewRequest(method, s.URL+path, r)
			req.Header.Set("Authorization", "Bearer "+key.Key)
			if body != nil {
				req.Header.Set("Content-Type", "application/json")
			}
			resp, err := http.DefaultClient.Do(req)
			if err != nil {
				t.Fatalf("%s %s: %v", method, path, err)
			}
			return resp
		},
	}
}

// postToIntegration sends one firing alert on a team's integration key, the way
// a real Alertmanager receiver would.
func postToIntegration(t *testing.T, s *ts, key, fingerprint, name string) {
	t.Helper()
	payload := map[string]any{
		"version":     "4",
		"status":      "firing",
		"groupKey":    "{}:{alertname=\"" + name + "\"}",
		"groupLabels": map[string]string{"alertname": name},
		"alerts": []map[string]any{
			amAlert(fingerprint, name, "firing", "2026-09-20T10:00:00Z", zeroTime, nil),
		},
	}
	data, _ := json.Marshal(payload)
	resp, err := http.Post(s.URL+"/api/integrations/"+key+"/alertmanager",
		"application/json", bytes.NewReader(data))
	if err != nil {
		t.Fatalf("post alert: %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("post alert: %d", resp.StatusCode)
	}
}

func list(t *testing.T, resp *http.Response) []map[string]any {
	t.Helper()
	var out []map[string]any
	decode(t, resp, &out)
	return out
}

// An alert posted on one team's key opens an incident in that team and nowhere
// else, and neither team can read the other's queue.
func TestTeams_IncidentsAreScopedToTheReceivingTeam(t *testing.T) {
	s := newTS(t)
	red := newTeam(t, s, "red")
	blue := newTeam(t, s, "blue")

	postToIntegration(t, s, red.key, "fp-red", "RedDiskFull")
	postToIntegration(t, s, blue.key, "fp-blue", "BlueDiskFull")

	redIncidents := list(t, red.call(http.MethodGet, "/api/incidents", nil))
	if len(redIncidents) != 1 {
		t.Fatalf("red should see exactly its own incident, saw %d", len(redIncidents))
	}
	if title := redIncidents[0]["title"]; title != "RedDiskFull" {
		t.Errorf("red saw %v", title)
	}
	if teamID := int64(redIncidents[0]["team_id"].(float64)); teamID != red.id {
		t.Errorf("red's incident belongs to team %d, want %d", teamID, red.id)
	}

	blueIncidents := list(t, blue.call(http.MethodGet, "/api/incidents", nil))
	if len(blueIncidents) != 1 || blueIncidents[0]["title"] != "BlueDiskFull" {
		t.Fatalf("blue should see exactly its own incident, saw %v", blueIncidents)
	}

	// Reading the other team's incident by id is not found rather than
	// forbidden: its existence is the other team's business.
	otherID := int64(blueIncidents[0]["id"].(float64))
	for _, path := range []string{
		"/api/incidents/" + id64(otherID),
		"/api/incidents/" + id64(otherID) + "/alerts",
		"/api/incidents/" + id64(otherID) + "/timeline",
	} {
		resp := red.call(http.MethodGet, path, nil)
		resp.Body.Close()
		if resp.StatusCode != http.StatusNotFound {
			t.Errorf("red reading %s: expected 404, got %d", path, resp.StatusCode)
		}
	}

	// And cannot act on it either.
	for _, path := range []string{"/acknowledge", "/resolve", "/archive"} {
		resp := red.call(http.MethodPost, "/api/incidents/"+id64(otherID)+path, nil)
		resp.Body.Close()
		if resp.StatusCode != http.StatusNotFound {
			t.Errorf("red posting %s: expected 404, got %d", path, resp.StatusCode)
		}
	}
}

// Alerts, the raw signal record, are scoped the same way.
func TestTeams_AlertsAndStatsAreScoped(t *testing.T) {
	s := newTS(t)
	red := newTeam(t, s, "red")
	blue := newTeam(t, s, "blue")

	postToIntegration(t, s, red.key, "fp-red", "RedDiskFull")
	postToIntegration(t, s, blue.key, "fp-blue-1", "BlueDiskFull")
	postToIntegration(t, s, blue.key, "fp-blue-2", "BlueMemory")

	if alerts := list(t, red.call(http.MethodGet, "/api/alerts", nil)); len(alerts) != 1 {
		t.Errorf("red should see 1 alert, saw %d", len(alerts))
	}
	if alerts := list(t, blue.call(http.MethodGet, "/api/alerts", nil)); len(alerts) != 2 {
		t.Errorf("blue should see 2 alerts, saw %d", len(alerts))
	}

	// Statistics count your own work only — otherwise a team's volume, and the
	// names of its alerts, leak through the totals.
	var stats map[string]any
	decode(t, red.call(http.MethodGet, "/api/stats/alerts", nil), &stats)
	if total := stats["total"].(float64); total != 1 {
		t.Errorf("red's alert stats counted %v alerts, want 1", total)
	}

	top := list(t, red.call(http.MethodGet, "/api/stats/alerts/top", nil))
	for _, row := range top {
		if name := row["name"].(string); name != "RedDiskFull" {
			t.Errorf("red's top alerts named %q, which is not theirs", name)
		}
	}
}

// The same fingerprint, the same groupKey and the same date are all legitimate
// in two teams at once: two clusters running the same rules, two rotas.
func TestTeams_SameFingerprintInTwoTeams(t *testing.T) {
	s := newTS(t)
	red := newTeam(t, s, "red")
	blue := newTeam(t, s, "blue")

	postToIntegration(t, s, red.key, "fp-shared", "DiskFull")
	postToIntegration(t, s, blue.key, "fp-shared", "DiskFull")

	for _, team := range []struct {
		name string
		f    teamFixture
	}{{"red", red}, {"blue", blue}} {
		incidents := list(t, team.f.call(http.MethodGet, "/api/incidents", nil))
		if len(incidents) != 1 {
			t.Errorf("%s: expected its own incident for the shared fingerprint, saw %d",
				team.name, len(incidents))
		}
	}

	// And both rotas can name somebody for the same day.
	for _, team := range []struct {
		name string
		f    teamFixture
	}{{"red", red}, {"blue", blue}} {
		var members []map[string]any
		decode(t, team.f.call(http.MethodGet, "/api/teams/"+id64(team.f.id)+"/members", nil), &members)
		userID := int64(members[0]["user_id"].(float64))

		resp := team.f.call(http.MethodPost, "/api/teams/"+id64(team.f.id)+"/schedule",
			map[string]any{"user_id": userID, "dates": []string{"2026-10-01"}})
		resp.Body.Close()
		if resp.StatusCode != http.StatusCreated {
			t.Errorf("%s: taking 2026-10-01 returned %d", team.name, resp.StatusCode)
		}
	}
}

// An unknown key delivers nothing, and says so rather than accepting silently.
func TestTeams_UnknownIntegrationKeyIsRejected(t *testing.T) {
	s := newTS(t)
	team := newTeam(t, s, "red")

	resp, err := http.Post(s.URL+"/api/integrations/not-a-real-key/alertmanager",
		"application/json", bytes.NewReader([]byte(`{"version":"4","status":"firing","alerts":[]}`)))
	if err != nil {
		t.Fatalf("post: %v", err)
	}
	resp.Body.Close()
	if resp.StatusCode != http.StatusUnauthorized {
		t.Errorf("expected 401 for an unknown key, got %d", resp.StatusCode)
	}

	if incidents := list(t, team.call(http.MethodGet, "/api/incidents", nil)); len(incidents) != 0 {
		t.Errorf("a rejected payload opened %d incident(s)", len(incidents))
	}
}

// Team configuration is an owner's job; working incidents is a member's.
func TestTeams_MemberCannotConfigureTheTeam(t *testing.T) {
	s := newTS(t)
	team := newTeam(t, s, "red")

	// A plain member of the same team.
	var user struct {
		ID int64 `json:"id"`
	}
	decode(t, s.req(t, http.MethodPost, "/api/users",
		map[string]string{"username": "plain", "email": "plain@test.com"}), &user)
	resp := s.req(t, http.MethodPost, "/api/teams/"+id64(team.id)+"/members",
		map[string]any{"user_id": user.ID, "role": "member"})
	resp.Body.Close()
	var key struct {
		Key string `json:"key"`
	}
	decode(t, s.req(t, http.MethodPost, "/api/users/"+id64(user.ID)+"/api-keys",
		map[string]string{"name": "test"}), &key)

	call := func(method, path string, body any) *http.Response {
		t.Helper()
		var r io.Reader
		if body != nil {
			data, _ := json.Marshal(body)
			r = bytes.NewReader(data)
		}
		req, _ := http.NewRequest(method, s.URL+path, r)
		req.Header.Set("Authorization", "Bearer "+key.Key)
		if body != nil {
			req.Header.Set("Content-Type", "application/json")
		}
		resp, err := http.DefaultClient.Do(req)
		if err != nil {
			t.Fatalf("%s %s: %v", method, path, err)
		}
		return resp
	}

	base := "/api/teams/" + id64(team.id)
	for _, c := range []struct {
		name   string
		method string
		path   string
		body   any
	}{
		{"mint an integration key", http.MethodPost, base + "/integrations",
			map[string]string{"name": "mine"}},
		{"take a shift", http.MethodPost, base + "/schedule",
			map[string]any{"user_id": user.ID, "dates": []string{"2026-11-01"}}},
		{"add a member", http.MethodPost, base + "/members",
			map[string]any{"user_id": 1}},
		{"delete the team", http.MethodDelete, base, nil},
	} {
		resp := call(c.method, c.path, c.body)
		resp.Body.Close()
		if resp.StatusCode != http.StatusForbidden {
			t.Errorf("%s: expected 403, got %d", c.name, resp.StatusCode)
		}
	}

	// But they can read what the team is doing.
	for _, path := range []string{base + "/members", base + "/integrations", base + "/schedule"} {
		resp := call(http.MethodGet, path, nil)
		resp.Body.Close()
		if resp.StatusCode != http.StatusOK {
			t.Errorf("reading %s: expected 200, got %d", path, resp.StatusCode)
		}
	}
}

// A team is not somewhere an outsider can look, whatever they know about it.
func TestTeams_OutsiderSeesNothing(t *testing.T) {
	s := newTS(t)
	red := newTeam(t, s, "red")
	blue := newTeam(t, s, "blue")

	base := "/api/teams/" + id64(red.id)
	for _, path := range []string{base + "/members", base + "/integrations", base + "/schedule"} {
		resp := blue.call(http.MethodGet, path, nil)
		resp.Body.Close()
		if resp.StatusCode != http.StatusNotFound {
			t.Errorf("blue reading %s: expected 404, got %d", path, resp.StatusCode)
		}
	}

	// /api/teams lists your own, never the install's.
	teams := list(t, blue.call(http.MethodGet, "/api/teams", nil))
	if len(teams) != 1 || teams[0]["name"] != "blue" {
		t.Errorf("blue's team list: %v", teams)
	}
}