package main

import (
	"context"
	"encoding/base64"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"
)

func postAndReceive(t *testing.T, ts *httptest.Server, broker *Broker, contentType string, body string) *Event {
	t.Helper()
	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
	defer cancel()

	ch, unsub := broker.Subscribe("test", "")
	defer unsub()

	req, _ := http.NewRequestWithContext(ctx, "POST", ts.URL+"/test", strings.NewReader(body))
	req.Header.Set("Content-Type", contentType)
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("POST failed: %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusAccepted {
		t.Fatalf("expected 202, got %d", resp.StatusCode)
	}

	select {
	case event := <-ch:
		return event
	case <-ctx.Done():
		t.Fatal("timed out waiting for event")
		return nil
	}
}

func TestServer_postFormDataStoredAsText(t *testing.T) {
	ts, broker, cancel := newTestServer(nil)
	defer cancel()
	defer ts.Close()

	event := postAndReceive(t, ts, broker, "application/x-www-form-urlencoded", "foo=bar&baz=qux")

	s, ok := event.Payload.(string)
	if !ok {
		t.Fatalf("expected string payload, got %T", event.Payload)
	}
	if s != "foo=bar&baz=qux" {
		t.Errorf("expected raw form data, got %s", s)
	}
}

func TestServer_postPlainTextStoredAsText(t *testing.T) {
	ts, broker, cancel := newTestServer(nil)
	defer cancel()
	defer ts.Close()

	event := postAndReceive(t, ts, broker, "text/plain", "hello world")

	s, ok := event.Payload.(string)
	if !ok {
		t.Fatalf("expected string payload, got %T", event.Payload)
	}
	if s != "hello world" {
		t.Errorf("expected raw text, got %s", s)
	}
}

func TestServer_postBinaryBase64Encoded(t *testing.T) {
	ts, broker, cancel := newTestServer(nil)
	defer cancel()
	defer ts.Close()

	event := postAndReceive(t, ts, broker, "application/octet-stream", "\x00\x01\x02\x03")

	s, ok := event.Payload.(string)
	if !ok {
		t.Fatalf("expected string payload, got %T", event.Payload)
	}
	expected := base64.StdEncoding.EncodeToString([]byte("\x00\x01\x02\x03"))
	if s != expected {
		t.Errorf("expected base64 %s, got %s", expected, s)
	}
}

func TestServer_postIncludesMethod(t *testing.T) {
	ts, broker, cancel := newTestServer(nil)
	defer cancel()
	defer ts.Close()

	event := postAndReceive(t, ts, broker, "application/json", `{"ok":true}`)

	if event.Method != "POST" {
		t.Errorf("expected method POST, got %s", event.Method)
	}
}

func TestServer_postMalformedContentTypeFallsBackToBase64(t *testing.T) {
	ts, broker, cancel := newTestServer(nil)
	defer cancel()
	defer ts.Close()

	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
	defer cancel()

	ch, unsub := broker.Subscribe("test", "")
	defer unsub()

	req, _ := http.NewRequestWithContext(ctx, "POST", ts.URL+"/test", strings.NewReader("some data"))
	req.Header.Set("Content-Type", ";;;malformed")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("POST failed: %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusAccepted {
		t.Fatalf("expected 202, got %d", resp.StatusCode)
	}

	select {
	case event := <-ch:
		s, ok := event.Payload.(string)
		if !ok {
			t.Fatalf("expected string payload, got %T", event.Payload)
		}
		expected := base64.StdEncoding.EncodeToString([]byte("some data"))
		if s != expected {
			t.Errorf("expected base64 %s, got %s", expected, s)
		}
	case <-ctx.Done():
		t.Fatal("timed out waiting for event")
	}
}

func TestIsTextContent(t *testing.T) {
	tests := []struct {
		name      string
		mediaType string
		params    map[string]string
		want      bool
	}{
		{"text/plain", "text/plain", nil, true},
		{"text/html", "text/html", nil, true},
		{"text/xml", "text/xml", nil, true},
		{"form urlencoded", "application/x-www-form-urlencoded", nil, true},
		{"application/xml", "application/xml", nil, true},
		{"application/xhtml+xml", "application/xhtml+xml", nil, true},
		{"charset param on non-text", "application/octet-stream", map[string]string{"charset": "utf-8"}, true},
		{"application/json", "application/json", nil, false},
		{"application/octet-stream", "application/octet-stream", nil, false},
		{"image/png", "image/png", nil, false},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := isTextContent(tt.mediaType, tt.params)
			if got != tt.want {
				t.Errorf("isTextContent(%q, %v) = %v, want %v", tt.mediaType, tt.params, got, tt.want)
			}
		})
	}
}

func TestServer_postJSONViaSSERoundTrip(t *testing.T) {
	ts, _, cancel := newTestServer(nil)
	defer cancel()
	defer ts.Close()

	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
	defer cancel()

	events := sseSubscribe(ctx, ts.URL+"/test", nil)
	time.Sleep(50 * time.Millisecond)

	http.Post(ts.URL+"/test", "application/json", strings.NewReader(`{"key":"value"}`))

	select {
	case event := <-events:
		if event.Method != "POST" {
			t.Errorf("expected method POST in SSE event, got %s", event.Method)
		}
		data, _ := json.Marshal(event.Payload)
		var m map[string]string
		json.Unmarshal(data, &m)
		if m["key"] != "value" {
			t.Errorf("expected key=value, got %v", m)
		}
	case <-ctx.Done():
		t.Fatal("timed out waiting for SSE event")
	}
}