package httpapi

import (
	"errors"
	"io"
	"log"
	"net/http"
	"net/http/httptest"
	"net/netip"
	"path/filepath"
	"strings"
	"testing"

	"scratchbox/internal/config"
	"scratchbox/internal/storage"
)

func TestMultipartFileCount(t *testing.T) {
	t.Parallel()

	req := httptest.NewRequest(http.MethodPost, "/api/scratch", nil)
	if got := multipartFileCount(req); got != 0 {
		t.Fatalf("multipartFileCount() = %d, want 0", got)
	}
}

func TestWriteCreateErrorBranches(t *testing.T) {
	t.Parallel()

	s := &Server{}
	rec1 := httptest.NewRecorder()
	s.writeCreateError(rec1, &http.MaxBytesError{Limit: 5})
	if rec1.Code != http.StatusRequestEntityTooLarge {
		t.Fatalf("max bytes error status = %d, want %d", rec1.Code, http.StatusRequestEntityTooLarge)
	}

	rec2 := httptest.NewRecorder()
	s.writeCreateError(rec2, errors.New("request body too large"))
	if rec2.Code != http.StatusRequestEntityTooLarge {
		t.Fatalf("body too large string status = %d, want %d", rec2.Code, http.StatusRequestEntityTooLarge)
	}

	rec3 := httptest.NewRecorder()
	s.writeCreateError(rec3, errors.New("other parse failure"))
	if rec3.Code != http.StatusBadRequest {
		t.Fatalf("generic error status = %d, want %d", rec3.Code, http.StatusBadRequest)
	}
}

func TestNewServerInitializes(t *testing.T) {
	tmp := t.TempDir()
	store, err := storage.NewFilesystemStore(filepath.Join(tmp, "data"), testStorageKey)
	if err != nil {
		t.Fatalf("NewFilesystemStore() error = %v", err)
	}
	cfg := config.Config{
		Limits: config.LimitsConfig{MaxUploadSizeBytes: 1024},
		Security: config.SecurityConfig{
			RateLimitUI:       config.RateLimitConfig{Enabled: false, RequestsPerMinute: 30, Burst: 10},
			RateLimitAPIRead:  config.RateLimitConfig{Enabled: false, RequestsPerMinute: 30, Burst: 10},
			RateLimitAPIWrite: config.RateLimitConfig{Enabled: false, RequestsPerMinute: 30, Burst: 10},
			HSTSEnabled:       true,
		},
	}

	srv, err := NewServer(cfg, store, log.New(io.Discard, "", 0), log.New(io.Discard, "", 0))
	if err != nil {
		t.Fatalf("NewServer() error = %v", err)
	}
	if srv == nil {
		t.Fatalf("expected initialized server")
	}
}

func TestGetUIConfig(t *testing.T) {
	t.Parallel()

	s := &Server{
		cfg: config.Config{
			Limits: config.LimitsConfig{
				MaxUploadSizeBytes: 2048,
			},
		},
	}
	rec := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/api/config", nil)
	s.getUIConfig(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
	}
	if got := rec.Body.String(); got == "" || !containsAll(got, "max_upload_size_bytes", "2048", `"upload_allowed":true`) {
		t.Fatalf("unexpected body: %q", got)
	}
}

func TestGetUIConfigUploadDenied(t *testing.T) {
	t.Parallel()

	s := &Server{
		cfg: config.Config{
			Limits: config.LimitsConfig{
				MaxUploadSizeBytes: 2048,
			},
			Security: config.SecurityConfig{
				AllowedPrefixes: []netip.Prefix{
					netip.MustParsePrefix("10.0.0.0/8"),
				},
			},
		},
	}
	rec := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/api/config", nil)
	s.getUIConfig(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
	}
	if got := rec.Body.String(); got == "" || !containsAll(got, `"upload_allowed":false`) {
		t.Fatalf("unexpected body: %q", got)
	}
}

func TestWriteCreateErrorBranchesWithConfig(t *testing.T) {
	tmp := t.TempDir()
	store, err := storage.NewFilesystemStore(filepath.Join(tmp, "data"), testStorageKey)
	if err != nil {
		t.Fatalf("NewFilesystemStore() error = %v", err)
	}
	cfg := config.Config{
		Limits: config.LimitsConfig{MaxUploadSizeBytes: 1024},
		Security: config.SecurityConfig{
			RateLimitUI:       config.RateLimitConfig{Enabled: false, RequestsPerMinute: 30, Burst: 10},
			RateLimitAPIRead:  config.RateLimitConfig{Enabled: false, RequestsPerMinute: 30, Burst: 10},
			RateLimitAPIWrite: config.RateLimitConfig{Enabled: false, RequestsPerMinute: 30, Burst: 10},
			HSTSEnabled:       true,
		},
	}
	if _, err := NewServer(cfg, store, log.New(io.Discard, "", 0), log.New(io.Discard, "", 0)); err != nil {
		t.Fatalf("NewServer() error = %v", err)
	}
}

func containsAll(haystack string, needles ...string) bool {
	for _, needle := range needles {
		if !strings.Contains(haystack, needle) {
			return false
		}
	}
	return true
}

// TestInjectMetaEscapesSpecialChars exercises the server-side meta injection
// (used for /s/{id} and 410 pages) with filenames/titles containing HTML special
// chars. This provides basic coverage/golden-like check for the replace+escape
// logic against the exact literals in the committed static shell (addresses
// fragility note without changing to full template).
func TestInjectMetaEscapesSpecialChars(t *testing.T) {
	t.Parallel()

	// Minimal shell containing exactly the replace targets used by injectMeta.
	// (Real index.html from Vite is larger but uses these literal strings.)
	shell := []byte(`<!doctype html>
<html><head>
<title>Scratchbox</title>
<meta property="og:title" content="Scratchbox" />
<meta name="twitter:title" content="Scratchbox" />
<meta name="description" content="Minimal temporary file sharing. Upload once, share the link, auto-expires." />
<meta property="og:description" content="Minimal temporary file sharing. Upload once, share the link, auto-expires." />
<meta name="twitter:description" content="Minimal temporary file sharing. Upload once, share the link, auto-expires." />
</head><body></body></html>`)

	tricky := `report & "notes" <2026> 'foo'`
	gotBytes := injectMeta(shell, tricky, tricky, tricky)
	got := string(gotBytes)

	// Must have escaped the specials.
	if !strings.Contains(got, `&amp;`) || !strings.Contains(got, `&lt;`) || !strings.Contains(got, `&gt;`) || !strings.Contains(got, `&quot;`) {
		t.Fatalf("injectMeta did not escape specials in output: %q", got)
	}
	// Title etc updated (escaped form present).
	if !strings.Contains(got, `report &amp; &quot;notes&quot; &lt;2026&gt;`) {
		t.Fatalf("injectMeta title not updated or badly escaped: %q", got)
	}
	// Original static should be gone (count=1 replaces).
	if strings.Contains(got, `<title>Scratchbox</title>`) {
		t.Fatalf("static title not replaced")
	}
}