package api

import (
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"github.com/kami/hexis/internal/domain"
	"github.com/kami/hexis/internal/execution"
	"github.com/kami/hexis/internal/provider"
	"github.com/kami/hexis/internal/storage"
)

func newTestHandler(t *testing.T) (*Handler, *storage.Store) {
	t.Helper()
	path := filepath.Join(t.TempDir(), "hexis.db")
	store, err := storage.Open(path)
	if err != nil {
		t.Fatalf("open store: %v", err)
	}
	t.Cleanup(func() { store.Close() })
	engine := execution.New(store, provider.NewRegistry())
	return NewHandler(store, engine, testToken), store
}

const testToken = "test-token"

// TestHandleChanges_SinceFiltersEvents verifies the `since` query param
// actually filters to events after that sequence number, rather than being
// silently reset to 0 (the bug: `since = 0` unconditionally, ignoring the
// parsed value).
func TestHandleChanges_SinceFiltersEvents(t *testing.T) {
	h, store := newTestHandler(t)

	for i := 0; i < 3; i++ {
		if err := store.AppendEvent(&domain.Event{
			ID:        domain.NewEventID(),
			Type:      domain.EventCapabilityRegistered,
			Timestamp: time.Now().UTC(),
		}); err != nil {
			t.Fatalf("append event %d: %v", i, err)
		}
	}

	all, err := store.EventsAfter(0, 100)
	if err != nil {
		t.Fatalf("events after 0: %v", err)
	}
	if len(all) != 3 {
		t.Fatalf("expected 3 seed events, got %d", len(all))
	}
	cutoff := all[0].Sequence

	req := httptest.NewRequest(http.MethodGet, "/api/v1/changes?since="+itoa(cutoff), nil)
	w := httptest.NewRecorder()
	h.handleChanges(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}

	var events []*domain.Event
	if err := json.Unmarshal(w.Body.Bytes(), &events); err != nil {
		t.Fatalf("decode response: %v", err)
	}
	if len(events) != 2 {
		t.Fatalf("expected 2 events after sequence %d, got %d", cutoff, len(events))
	}
	for _, e := range events {
		if e.Sequence <= cutoff {
			t.Errorf("event with sequence %d should have been excluded by since=%d", e.Sequence, cutoff)
		}
	}
}

func itoa(n int64) string {
	b, _ := json.Marshal(n)
	return string(b)
}

// TestAPIV1_RequiresBearerToken pins finding 2: /api/v1/ must not be reachable
// without the shared token, while /health stays open for probes.
func TestAPIV1_RequiresBearerToken(t *testing.T) {
	h, _ := newTestHandler(t)
	mux := http.NewServeMux()
	h.Register(mux)

	body := `{"capability_id":"cap_x","target_entity_id":"ent_x"}`

	cases := []struct {
		name   string
		header string
		want   int
	}{
		{"no header", "", http.StatusUnauthorized},
		{"wrong token", "Bearer nope", http.StatusUnauthorized},
		{"not bearer", "Basic " + testToken, http.StatusUnauthorized},
		{"correct token", "Bearer " + testToken, http.StatusNotFound}, // past auth: capability missing
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			req := httptest.NewRequest(http.MethodPost, "/api/v1/execute", strings.NewReader(body))
			if tc.header != "" {
				req.Header.Set("Authorization", tc.header)
			}
			w := httptest.NewRecorder()
			mux.ServeHTTP(w, req)
			if w.Code != tc.want {
				t.Fatalf("expected %d, got %d: %s", tc.want, w.Code, w.Body.String())
			}
		})
	}

	// /health must remain unauthenticated.
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, httptest.NewRequest(http.MethodGet, "/health", nil))
	if w.Code != http.StatusOK {
		t.Fatalf("expected /health to stay open, got %d", w.Code)
	}
}

// TestAPIV1_UnsetTokenFailsClosed: an empty configured token must reject the
// API outright, never serve it openly.
func TestAPIV1_UnsetTokenFailsClosed(t *testing.T) {
	path := filepath.Join(t.TempDir(), "hexis.db")
	store, err := storage.Open(path)
	if err != nil {
		t.Fatalf("open store: %v", err)
	}
	t.Cleanup(func() { store.Close() })
	h := NewHandler(store, execution.New(store, provider.NewRegistry()), "")
	mux := http.NewServeMux()
	h.Register(mux)

	req := httptest.NewRequest(http.MethodGet, "/api/v1/capabilities", nil)
	req.Header.Set("Authorization", "Bearer anything")
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, req)
	if w.Code != http.StatusServiceUnavailable {
		t.Fatalf("expected 503 when no token is configured, got %d: %s", w.Code, w.Body.String())
	}
}

// TestCreateCapability_GuardsAreServerDerived pins finding 2: a caller cannot
// enable a destructive capability or opt out of confirmation via the body.
func TestCreateCapability_GuardsAreServerDerived(t *testing.T) {
	h, _ := newTestHandler(t)

	cases := []struct {
		name                     string
		body                     string
		wantEnabled              bool
		wantRequiresConfirmation bool
	}{
		{
			name:        "destructive cannot be enabled from the body",
			body:        `{"name":"prune","provider":"workspace_mcp","operation":"docker.prune","risk":"destructive","enabled":true}`,
			wantEnabled: false, wantRequiresConfirmation: true,
		},
		{
			name:        "medium risk gets confirmation even when the body says otherwise",
			body:        `{"name":"stop","provider":"workspace_mcp","operation":"docker.stop_container","risk":"medium","requires_confirmation":false}`,
			wantEnabled: true, wantRequiresConfirmation: true,
		},
		{
			name:        "read risk stays confirmation-free",
			body:        `{"name":"list","provider":"workspace_mcp","operation":"docker.list_containers","risk":"read"}`,
			wantEnabled: true, wantRequiresConfirmation: false,
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			req := httptest.NewRequest(http.MethodPost, "/api/v1/capabilities", strings.NewReader(tc.body))
			w := httptest.NewRecorder()
			h.createCapability(w, req)
			if w.Code != http.StatusCreated {
				t.Fatalf("expected 201, got %d: %s", w.Code, w.Body.String())
			}
			var cap domain.Capability
			if err := json.Unmarshal(w.Body.Bytes(), &cap); err != nil {
				t.Fatalf("decode: %v", err)
			}
			if cap.Enabled != tc.wantEnabled {
				t.Errorf("enabled = %v, want %v", cap.Enabled, tc.wantEnabled)
			}
			if cap.RequiresConfirmation != tc.wantRequiresConfirmation {
				t.Errorf("requires_confirmation = %v, want %v", cap.RequiresConfirmation, tc.wantRequiresConfirmation)
			}
			if cap.TimeoutSeconds != domain.DefaultCapabilityTimeoutSeconds {
				t.Errorf("timeout_seconds = %d, want %d", cap.TimeoutSeconds, domain.DefaultCapabilityTimeoutSeconds)
			}
		})
	}
}

// TestExecute_WorkspaceCapabilityEndToEnd pins finding 1: a capability
// registered by BuildCapabilities must actually execute, not 403 as disabled.
func TestExecute_WorkspaceCapabilityEndToEnd(t *testing.T) {
	ws := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/tool/docker.list_containers" {
			http.NotFound(w, r)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"containers":["hexis"]}`))
	}))
	t.Cleanup(ws.Close)

	allowlistPath := filepath.Join(t.TempDir(), "allowlist.yaml")
	allowlistYAML := "tools:\n" +
		"  docker.list_containers:\n" +
		"    capability: workspace.docker.list\n" +
		"    risk: read\n" +
		"    read_only: true\n"
	if err := os.WriteFile(allowlistPath, []byte(allowlistYAML), 0o600); err != nil {
		t.Fatalf("write allowlist: %v", err)
	}
	allowlist, err := provider.LoadToolAllowlist(allowlistPath)
	if err != nil {
		t.Fatalf("load allowlist: %v", err)
	}

	store, err := storage.Open(filepath.Join(t.TempDir(), "hexis.db"))
	if err != nil {
		t.Fatalf("open store: %v", err)
	}
	t.Cleanup(func() { store.Close() })

	wsProvider := provider.NewWorkspaceMCPProvider(ws.URL, allowlist)
	reg := provider.NewRegistry()
	reg.Register(wsProvider)

	caps := wsProvider.BuildCapabilities()
	if len(caps) != 1 {
		t.Fatalf("expected 1 built capability, got %d", len(caps))
	}
	built := caps[0]
	if !built.Enabled {
		t.Fatalf("BuildCapabilities produced a disabled capability: %+v", built)
	}
	if built.TimeoutSeconds <= 0 {
		t.Fatalf("BuildCapabilities produced timeout_seconds=%d", built.TimeoutSeconds)
	}
	if err := store.CreateCapability(&built); err != nil {
		t.Fatalf("create capability: %v", err)
	}

	h := NewHandler(store, execution.New(store, reg), testToken)
	mux := http.NewServeMux()
	h.Register(mux)

	body := `{"capability_id":"` + built.ID + `","target_entity_id":"ent_host_homesrv"}`
	req := httptest.NewRequest(http.MethodPost, "/api/v1/execute", strings.NewReader(body))
	req.Header.Set("Authorization", "Bearer "+testToken)
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}
	var exec domain.Execution
	if err := json.Unmarshal(w.Body.Bytes(), &exec); err != nil {
		t.Fatalf("decode execution: %v", err)
	}
	if exec.Status != domain.ExecutionSucceeded {
		t.Fatalf("expected succeeded, got %q (error: %s)", exec.Status, exec.Error)
	}
}

// TestBuildCapabilities_RiskDerivation pins that mutating workspace tools are
// registered enabled but confirmation-gated.
func TestBuildCapabilities_RiskDerivation(t *testing.T) {
	allowlist := provider.ToolAllowlist{Tools: map[string]provider.ToolMapping{
		"docker.stop_container": {Capability: "workspace.docker.stop", Risk: "medium", TargetType: "container"},
	}}
	caps := provider.NewWorkspaceMCPProvider("http://unused", allowlist).BuildCapabilities()
	if len(caps) != 1 {
		t.Fatalf("expected 1 capability, got %d", len(caps))
	}
	if !caps[0].Enabled {
		t.Errorf("medium-risk capability should be enabled")
	}
	if !caps[0].RequiresConfirmation {
		t.Errorf("medium-risk capability must require confirmation")
	}
}