package control

import (
	"bytes"
	"encoding/json"
	"errors"
	"net/http"
	"net/http/httptest"
	"testing"

	cfgpkg "github.com/jan/fm-rds-tx/internal/config"
)

func TestHealthz(t *testing.T) {
	srv := NewServer(cfgpkg.Default())
	rec := httptest.NewRecorder()
	srv.Handler().ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/healthz", nil))
	if rec.Code != 200 {
		t.Fatalf("status: %d", rec.Code)
	}
}

func TestStatus(t *testing.T) {
	srv := NewServer(cfgpkg.Default())
	rec := httptest.NewRecorder()
	srv.Handler().ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/status", nil))
	if rec.Code != 200 {
		t.Fatalf("status: %d", rec.Code)
	}
	var body map[string]any
	json.Unmarshal(rec.Body.Bytes(), &body)
	if body["service"] != "fm-rds-tx" {
		t.Fatal("missing service")
	}
	if _, ok := body["preEmphasisTauUS"]; !ok {
		t.Fatal("missing preEmphasisTauUS")
	}
}

func TestStatusReportsRuntimeIndicator(t *testing.T) {
	srv := NewServer(cfgpkg.Default())
	srv.SetTXController(&fakeTXController{stats: map[string]any{"runtimeIndicator": "degraded"}})
	rec := httptest.NewRecorder()
	srv.Handler().ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/status", nil))
	if rec.Code != 200 {
		t.Fatalf("status: %d", rec.Code)
	}
	var body map[string]any
	json.Unmarshal(rec.Body.Bytes(), &body)
	if body["runtimeIndicator"] != "degraded" {
		t.Fatalf("expected runtimeIndicator degraded, got %v", body["runtimeIndicator"])
	}
}

func TestDryRunEndpoint(t *testing.T) {
	srv := NewServer(cfgpkg.Default())
	rec := httptest.NewRecorder()
	srv.Handler().ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/dry-run", nil))
	if rec.Code != 200 {
		t.Fatalf("status: %d", rec.Code)
	}
	var body map[string]any
	json.Unmarshal(rec.Body.Bytes(), &body)
	if body["mode"] != "dry-run" {
		t.Fatal("wrong mode")
	}
}

func TestConfigPatch(t *testing.T) {
	srv := NewServer(cfgpkg.Default())
	body := []byte(`{"toneLeftHz":900,"radioText":"hello world","preEmphasisTauUS":75}`)
	rec := httptest.NewRecorder()
	srv.Handler().ServeHTTP(rec, httptest.NewRequest(http.MethodPost, "/config", bytes.NewReader(body)))
	if rec.Code != 200 {
		t.Fatalf("status: %d body=%s", rec.Code, rec.Body.String())
	}
}

func TestRuntimeWithoutDriver(t *testing.T) {
	srv := NewServer(cfgpkg.Default())
	rec := httptest.NewRecorder()
	srv.Handler().ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/runtime", nil))
	if rec.Code != 200 {
		t.Fatalf("status: %d", rec.Code)
	}
}

func TestTXStartWithoutController(t *testing.T) {
	srv := NewServer(cfgpkg.Default())
	rec := httptest.NewRecorder()
	srv.Handler().ServeHTTP(rec, httptest.NewRequest(http.MethodPost, "/tx/start", nil))
	if rec.Code != http.StatusServiceUnavailable {
		t.Fatalf("expected 503, got %d", rec.Code)
	}
}

func TestConfigPatchUpdatesSnapshot(t *testing.T) {
	srv := NewServer(cfgpkg.Default())
	srv.SetTXController(&fakeTXController{})

	rec := httptest.NewRecorder()
	body := []byte(`{"outputDrive":1.2}`)
	srv.Handler().ServeHTTP(rec, httptest.NewRequest(http.MethodPost, "/config", bytes.NewReader(body)))
	if rec.Code != 200 {
		t.Fatalf("status: %d", rec.Code)
	}
	var resp map[string]any
	if err := json.Unmarshal(rec.Body.Bytes(), &resp); err != nil {
		t.Fatalf("unmarshal response: %v", err)
	}
	if live, ok := resp["live"].(bool); !ok || !live {
		t.Fatalf("expected live true, got %v", resp["live"])
	}

	rec = httptest.NewRecorder()
	srv.Handler().ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/config", nil))
	var cfg cfgpkg.Config
	if err := json.NewDecoder(rec.Body).Decode(&cfg); err != nil {
		t.Fatalf("decode config: %v", err)
	}
	if cfg.FM.OutputDrive != 1.2 {
		t.Fatalf("expected snapshot to reflect new drive, got %v", cfg.FM.OutputDrive)
	}
}

func TestConfigPatchEngineRejectsDoesNotUpdateSnapshot(t *testing.T) {
	srv := NewServer(cfgpkg.Default())
	srv.SetTXController(&fakeTXController{updateErr: errors.New("boom")})

	body := []byte(`{"outputDrive":2.2}`)
	rec := httptest.NewRecorder()
	srv.Handler().ServeHTTP(rec, httptest.NewRequest(http.MethodPost, "/config", bytes.NewReader(body)))
	if rec.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d", rec.Code)
	}

	rec = httptest.NewRecorder()
	srv.Handler().ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/config", nil))
	var cfg cfgpkg.Config
	if err := json.NewDecoder(rec.Body).Decode(&cfg); err != nil {
		t.Fatalf("decode config: %v", err)
	}
	if cfg.FM.OutputDrive != cfgpkg.Default().FM.OutputDrive {
		t.Fatalf("expected snapshot untouched, got %v", cfg.FM.OutputDrive)
	}
}

type fakeTXController struct {
	updateErr error
	stats     map[string]any
}

func (f *fakeTXController) StartTX() error { return nil }
func (f *fakeTXController) StopTX() error  { return nil }
func (f *fakeTXController) TXStats() map[string]any {
	if f.stats != nil {
		return f.stats
	}
	return map[string]any{}
}
func (f *fakeTXController) UpdateConfig(_ LivePatch) error { return f.updateErr }