package httpapi

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"mime"
	"mime/multipart"
	"net/http"
	"net/http/httptest"
	"path/filepath"
	"strings"
	"sync"
	"testing"
	"time"

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

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      120 * time.Millisecond,
		rateLimitEnable: false,
	})

	createReq := httptest.NewRequest(http.MethodPost, "/api/scratch", bytes.NewBufferString("hello scratch"))
	createReq.Header.Set("Content-Type", "text/plain; charset=utf-8")
	createReq.RemoteAddr = "127.0.0.1:9999"
	createRec := httptest.NewRecorder()
	handler.ServeHTTP(createRec, createReq)
	if createRec.Code != http.StatusCreated {
		t.Fatalf("create status = %d, want %d", createRec.Code, http.StatusCreated)
	}

	var payload map[string]any
	if err := json.Unmarshal(createRec.Body.Bytes(), &payload); err != nil {
		t.Fatalf("decode create payload error = %v", err)
	}
	id, _ := payload["id"].(string)
	if id == "" {
		t.Fatalf("create payload missing id")
	}

	metaReq := httptest.NewRequest(http.MethodGet, "/api/scratch/"+id, nil)
	metaReq.RemoteAddr = "127.0.0.1:9999"
	metaRec := httptest.NewRecorder()
	handler.ServeHTTP(metaRec, metaReq)
	if metaRec.Code != http.StatusOK {
		t.Fatalf("read metadata status = %d, want %d", metaRec.Code, http.StatusOK)
	}

	rawReq := httptest.NewRequest(http.MethodGet, "/api/raw/"+id, nil)
	rawReq.RemoteAddr = "127.0.0.1:9999"
	rawRec := httptest.NewRecorder()
	handler.ServeHTTP(rawRec, rawReq)
	if rawRec.Code != http.StatusOK {
		t.Fatalf("read raw status = %d, want %d", rawRec.Code, http.StatusOK)
	}
	if got := rawRec.Body.String(); got != "hello scratch" {
		t.Fatalf("raw body = %q, want %q", got, "hello scratch")
	}

	time.Sleep(180 * time.Millisecond)

	expiredReq := httptest.NewRequest(http.MethodGet, "/api/scratch/"+id, nil)
	expiredReq.RemoteAddr = "127.0.0.1:9999"
	expiredRec := httptest.NewRecorder()
	handler.ServeHTTP(expiredRec, expiredReq)
	if expiredRec.Code != http.StatusGone {
		t.Fatalf("expired status = %d, want %d", expiredRec.Code, http.StatusGone)
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      120 * time.Millisecond,
		rateLimitEnable: false,
	})

	createReq := httptest.NewRequest(http.MethodPost, "/api/scratch", bytes.NewBufferString("hello from upload flow"))
	createReq.Header.Set("Content-Type", "text/plain; charset=utf-8")
	createReq.RemoteAddr = "127.0.0.1:5090"
	createRec := httptest.NewRecorder()
	handler.ServeHTTP(createRec, createReq)
	if createRec.Code != http.StatusCreated {
		t.Fatalf("create status = %d, want %d", createRec.Code, http.StatusCreated)
	}

	var payload map[string]any
	if err := json.Unmarshal(createRec.Body.Bytes(), &payload); err != nil {
		t.Fatalf("decode create payload error = %v", err)
	}
	id, _ := payload["id"].(string)
	if id == "" {
		t.Fatalf("create payload missing id")
	}

	viewReq := httptest.NewRequest(http.MethodGet, "/s/"+id, nil)
	viewReq.RemoteAddr = "127.0.0.1:5091"
	viewRec := httptest.NewRecorder()
	handler.ServeHTTP(viewRec, viewReq)
	if viewRec.Code != http.StatusOK {
		t.Fatalf("view-before-expiry status = %d, want %d", viewRec.Code, http.StatusOK)
	}
	if !strings.Contains(viewRec.Body.String(), `id="app"`) {
		t.Fatalf("expected SPA shell body for /s/{id}, got %q", viewRec.Body.String())
	}

	rawReq := httptest.NewRequest(http.MethodGet, "/api/raw/"+id, nil)
	rawReq.RemoteAddr = "127.0.0.1:5092"
	rawRec := httptest.NewRecorder()
	handler.ServeHTTP(rawRec, rawReq)
	if rawRec.Code != http.StatusOK {
		t.Fatalf("raw-before-expiry status = %d, want %d", rawRec.Code, http.StatusOK)
	}
	if got := rawRec.Body.String(); got != "hello from upload flow" {
		t.Fatalf("raw-before-expiry body = %q, want %q", got, "hello from upload flow")
	}

	time.Sleep(180 * time.Millisecond)

	viewExpiredReq := httptest.NewRequest(http.MethodGet, "/s/"+id, nil)
	viewExpiredReq.RemoteAddr = "127.0.0.1:5093"
	viewExpiredRec := httptest.NewRecorder()
	handler.ServeHTTP(viewExpiredRec, viewExpiredReq)
	if viewExpiredRec.Code != http.StatusGone {
		t.Fatalf("view-after-expiry status = %d, want %d", viewExpiredRec.Code, http.StatusGone)
	}
	if !strings.Contains(viewExpiredRec.Body.String(), `id="app"`) {
		t.Fatalf("expected SPA shell body for expired /s/{id}, got %q", viewExpiredRec.Body.String())
	}

	rawExpiredReq := httptest.NewRequest(http.MethodGet, "/api/raw/"+id, nil)
	rawExpiredReq.RemoteAddr = "127.0.0.1:5094"
	rawExpiredRec := httptest.NewRecorder()
	handler.ServeHTTP(rawExpiredRec, rawExpiredReq)
	if rawExpiredRec.Code != http.StatusGone {
		t.Fatalf("raw-after-expiry status = %d, want %d", rawExpiredRec.Code, http.StatusGone)
	}
	if rawExpiredRec.Body.Len() != 0 {
		t.Fatalf("expected empty raw body after expiry, got %q", rawExpiredRec.Body.String())
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: true,
	})

	createReq := httptest.NewRequest(http.MethodPost, "/api/scratch", bytes.NewBufferString("hello scratch"))
	createReq.Header.Set("Content-Type", "text/plain; charset=utf-8")
	createReq.RemoteAddr = "127.0.0.1:9111"
	createRec := httptest.NewRecorder()
	handler.ServeHTTP(createRec, createReq)
	if createRec.Code != http.StatusCreated {
		t.Fatalf("create status = %d, want %d", createRec.Code, http.StatusCreated)
	}

	var payload map[string]any
	if err := json.Unmarshal(createRec.Body.Bytes(), &payload); err != nil {
		t.Fatalf("decode create payload error = %v", err)
	}
	id, _ := payload["id"].(string)
	if id == "" {
		t.Fatalf("create payload missing id")
	}

	firstRawReq := httptest.NewRequest(http.MethodGet, "/api/raw/"+id, nil)
	firstRawReq.RemoteAddr = "127.0.0.1:9111"
	firstRawRec := httptest.NewRecorder()
	handler.ServeHTTP(firstRawRec, firstRawReq)
	if firstRawRec.Code != http.StatusOK {
		t.Fatalf("first raw status = %d, want %d", firstRawRec.Code, http.StatusOK)
	}

	secondRawReq := httptest.NewRequest(http.MethodGet, "/api/raw/"+id, nil)
	secondRawReq.RemoteAddr = "127.0.0.1:9111"
	secondRawRec := httptest.NewRecorder()
	handler.ServeHTTP(secondRawRec, secondRawReq)
	if secondRawRec.Code != http.StatusTooManyRequests {
		t.Fatalf("second raw status = %d, want %d", secondRawRec.Code, http.StatusTooManyRequests)
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  8,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	req := httptest.NewRequest(http.MethodPost, "/api/scratch", bytes.NewBufferString("this is too large"))
	req.Header.Set("Content-Type", "text/plain; charset=utf-8")
	req.RemoteAddr = "127.0.0.1:5050"
	rec := httptest.NewRecorder()

	handler.ServeHTTP(rec, req)
	if rec.Code != http.StatusRequestEntityTooLarge {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusRequestEntityTooLarge)
	}
	if !bytes.Contains(rec.Body.Bytes(), []byte("upload exceeds limits.max_upload_size")) {
		t.Fatalf("unexpected body: %q", rec.Body.String())
	}
	if !bytes.Contains(rec.Body.Bytes(), []byte("(8 bytes)")) {
		t.Fatalf("expected response to include configured max size, got: %q", rec.Body.String())
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  8,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	var body bytes.Buffer
	writer := multipart.NewWriter(&body)
	file, err := writer.CreateFormFile("file", "too-big.txt")
	if err != nil {
		t.Fatalf("CreateFormFile() error = %v", err)
	}
	if _, err := file.Write([]byte("this is too large")); err != nil {
		t.Fatalf("write file error = %v", err)
	}
	if err := writer.Close(); err != nil {
		t.Fatalf("multipart close error = %v", err)
	}

	req := httptest.NewRequest(http.MethodPost, "/api/scratch", &body)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.RemoteAddr = "127.0.0.1:5060"
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusRequestEntityTooLarge {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusRequestEntityTooLarge)
	}
	if !bytes.Contains(rec.Body.Bytes(), []byte("upload exceeds limits.max_upload_size")) {
		t.Fatalf("unexpected body: %q", rec.Body.String())
	}
	if !bytes.Contains(rec.Body.Bytes(), []byte("(8 bytes)")) {
		t.Fatalf("expected response to include configured max size, got: %q", rec.Body.String())
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	var body bytes.Buffer
	writer := multipart.NewWriter(&body)
	file1, err := writer.CreateFormFile("file", "first.txt")
	if err != nil {
		t.Fatalf("CreateFormFile first error = %v", err)
	}
	if _, err := file1.Write([]byte("first")); err != nil {
		t.Fatalf("write first file error = %v", err)
	}
	file2, err := writer.CreateFormFile("file", "second.txt")
	if err != nil {
		t.Fatalf("CreateFormFile second error = %v", err)
	}
	if _, err := file2.Write([]byte("second")); err != nil {
		t.Fatalf("write second file error = %v", err)
	}
	if err := writer.Close(); err != nil {
		t.Fatalf("multipart close error = %v", err)
	}

	req := httptest.NewRequest(http.MethodPost, "/api/scratch", &body)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.RemoteAddr = "127.0.0.1:5051"
	rec := httptest.NewRecorder()

	handler.ServeHTTP(rec, req)
	if rec.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusBadRequest)
	}
	if !bytes.Contains(rec.Body.Bytes(), []byte("only one file is allowed per scratch upload")) {
		t.Fatalf("unexpected body: %q", rec.Body.String())
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	var body bytes.Buffer
	writer := multipart.NewWriter(&body)
	if err := writer.WriteField("content", "hello from content field"); err != nil {
		t.Fatalf("WriteField() error = %v", err)
	}
	if err := writer.Close(); err != nil {
		t.Fatalf("multipart close error = %v", err)
	}

	req := httptest.NewRequest(http.MethodPost, "/api/scratch", &body)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.RemoteAddr = "127.0.0.1:5052"
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusCreated {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusCreated)
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	var body bytes.Buffer
	writer := multipart.NewWriter(&body)
	file, err := writer.CreateFormFile("file", "example upload.txt")
	if err != nil {
		t.Fatalf("CreateFormFile() error = %v", err)
	}
	if _, err := file.Write([]byte("uploaded file body")); err != nil {
		t.Fatalf("write file error = %v", err)
	}
	if err := writer.Close(); err != nil {
		t.Fatalf("multipart close error = %v", err)
	}

	createReq := httptest.NewRequest(http.MethodPost, "/api/scratch", &body)
	createReq.Header.Set("Content-Type", writer.FormDataContentType())
	createReq.RemoteAddr = "127.0.0.1:5058"
	createRec := httptest.NewRecorder()
	handler.ServeHTTP(createRec, createReq)
	if createRec.Code != http.StatusCreated {
		t.Fatalf("status = %d, want %d", createRec.Code, http.StatusCreated)
	}

	var payload map[string]any
	if err := json.Unmarshal(createRec.Body.Bytes(), &payload); err != nil {
		t.Fatalf("decode create payload error = %v", err)
	}
	id, _ := payload["id"].(string)
	if id == "" {
		t.Fatalf("create payload missing id")
	}

	rawReq := httptest.NewRequest(http.MethodGet, "/api/raw/"+id, nil)
	rawReq.RemoteAddr = "127.0.0.1:5059"
	rawRec := httptest.NewRecorder()
	handler.ServeHTTP(rawRec, rawReq)
	if rawRec.Code != http.StatusOK {
		t.Fatalf("raw status = %d, want %d", rawRec.Code, http.StatusOK)
	}
	if got := rawRec.Body.String(); got != "uploaded file body" {
		t.Fatalf("raw body = %q, want %q", got, "uploaded file body")
	}

	disposition := rawRec.Header().Get("Content-Disposition")
	if disposition == "" {
		t.Fatalf("expected Content-Disposition header")
	}
	_, params, err := mime.ParseMediaType(disposition)
	if err != nil {
		t.Fatalf("ParseMediaType() error = %v", err)
	}
	if got := params["filename"]; got != "example upload.txt" {
		t.Fatalf("filename = %q, want %q", got, "example upload.txt")
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	var body bytes.Buffer
	writer := multipart.NewWriter(&body)
	file, err := writer.CreateFormFile("file", "one.txt")
	if err != nil {
		t.Fatalf("CreateFormFile() error = %v", err)
	}
	if _, err := file.Write([]byte("file content")); err != nil {
		t.Fatalf("write file error = %v", err)
	}
	if err := writer.WriteField("content", "extra content"); err != nil {
		t.Fatalf("WriteField() error = %v", err)
	}
	if err := writer.Close(); err != nil {
		t.Fatalf("multipart close error = %v", err)
	}

	req := httptest.NewRequest(http.MethodPost, "/api/scratch", &body)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.RemoteAddr = "127.0.0.1:5053"
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusBadRequest)
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	var body bytes.Buffer
	writer := multipart.NewWriter(&body)
	if err := writer.Close(); err != nil {
		t.Fatalf("multipart close error = %v", err)
	}

	req := httptest.NewRequest(http.MethodPost, "/api/scratch", &body)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.RemoteAddr = "127.0.0.1:5054"
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)
	if rec.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusBadRequest)
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	req := httptest.NewRequest(http.MethodGet, "/api/scratch/does-not-exist", nil)
	req.RemoteAddr = "127.0.0.1:5055"
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)
	if rec.Code != http.StatusGone {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusGone)
	}
}

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

	handler, store := newTestHandlerAndStore(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	meta, err := store.Create(t.Context(), strings.NewReader("no content type"), "", time.Hour)
	if err != nil {
		t.Fatalf("store.Create() error = %v", err)
	}

	req := httptest.NewRequest(http.MethodGet, "/api/raw/"+meta.ID, nil)
	req.RemoteAddr = "127.0.0.1:5056"
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
	}
	if got := rec.Header().Get("Content-Type"); got != "application/octet-stream" {
		t.Fatalf("Content-Type = %q, want %q", got, "application/octet-stream")
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	createReq := httptest.NewRequest(http.MethodPost, "/api/scratch", bytes.NewBufferString("hello scratch"))
	createReq.Header.Set("Content-Type", "text/plain; charset=utf-8")
	createReq.RemoteAddr = "127.0.0.1:5061"
	createRec := httptest.NewRecorder()
	handler.ServeHTTP(createRec, createReq)
	if createRec.Code != http.StatusCreated {
		t.Fatalf("create status = %d, want %d", createRec.Code, http.StatusCreated)
	}

	var payload map[string]any
	if err := json.Unmarshal(createRec.Body.Bytes(), &payload); err != nil {
		t.Fatalf("decode create payload error = %v", err)
	}
	id, _ := payload["id"].(string)
	if id == "" {
		t.Fatalf("create payload missing id")
	}

	rangeReq := httptest.NewRequest(http.MethodGet, "/api/raw/"+id, nil)
	rangeReq.Header.Set("Range", "bytes=0-4")
	rangeReq.RemoteAddr = "127.0.0.1:5062"
	rangeRec := httptest.NewRecorder()
	handler.ServeHTTP(rangeRec, rangeReq)
	if rangeRec.Code != http.StatusPartialContent {
		t.Fatalf("range status = %d, want %d", rangeRec.Code, http.StatusPartialContent)
	}
	if got := rangeRec.Body.String(); got != "hello" {
		t.Fatalf("range body = %q, want %q", got, "hello")
	}
	if got := rangeRec.Header().Get("Content-Range"); got != "bytes 0-4/13" {
		t.Fatalf("Content-Range = %q, want %q", got, "bytes 0-4/13")
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	createReq := httptest.NewRequest(http.MethodPost, "/api/scratch", bytes.NewBufferString("hello scratch"))
	createReq.Header.Set("Content-Type", "text/plain; charset=utf-8")
	createReq.RemoteAddr = "127.0.0.1:5063"
	createRec := httptest.NewRecorder()
	handler.ServeHTTP(createRec, createReq)
	if createRec.Code != http.StatusCreated {
		t.Fatalf("create status = %d, want %d", createRec.Code, http.StatusCreated)
	}

	var payload map[string]any
	if err := json.Unmarshal(createRec.Body.Bytes(), &payload); err != nil {
		t.Fatalf("decode create payload error = %v", err)
	}
	id, _ := payload["id"].(string)
	if id == "" {
		t.Fatalf("create payload missing id")
	}

	rangeReq := httptest.NewRequest(http.MethodGet, "/api/raw/"+id, nil)
	rangeReq.Header.Set("Range", "bytes=999-1000")
	rangeReq.RemoteAddr = "127.0.0.1:5064"
	rangeRec := httptest.NewRecorder()
	handler.ServeHTTP(rangeRec, rangeReq)
	if rangeRec.Code != http.StatusRequestedRangeNotSatisfiable {
		t.Fatalf("range status = %d, want %d", rangeRec.Code, http.StatusRequestedRangeNotSatisfiable)
	}
	if got := rangeRec.Header().Get("Content-Range"); got != "bytes */13" {
		t.Fatalf("Content-Range = %q, want %q", got, "bytes */13")
	}
}

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

	handler, store := newTestHandlerAndStore(t, testServerOptions{
		maxUploadBytes:  10 * 1024 * 1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	meta, err := store.Create(t.Context(), strings.NewReader("hello view"), "text/plain; charset=utf-8", time.Hour)
	if err != nil {
		t.Fatalf("store.Create() error = %v", err)
	}

	indexReq := httptest.NewRequest(http.MethodGet, "/", nil)
	indexRec := httptest.NewRecorder()
	handler.ServeHTTP(indexRec, indexReq)
	if indexRec.Code != http.StatusOK {
		t.Fatalf("index status = %d, want %d", indexRec.Code, http.StatusOK)
	}
	if !strings.Contains(indexRec.Body.String(), `id="app"`) {
		t.Fatalf("expected index page to include SPA mount point")
	}
	if !strings.Contains(indexRec.Body.String(), `type="module"`) {
		t.Fatalf("expected index page to load frontend bundle")
	}

	uploadReq := httptest.NewRequest(http.MethodGet, "/u", nil)
	uploadRec := httptest.NewRecorder()
	handler.ServeHTTP(uploadRec, uploadReq)
	if uploadRec.Code != http.StatusOK {
		t.Fatalf("upload status = %d, want %d", uploadRec.Code, http.StatusOK)
	}
	if !strings.Contains(uploadRec.Body.String(), `id="app"`) {
		t.Fatalf("expected upload page to include SPA mount point")
	}

	viewReq := httptest.NewRequest(http.MethodGet, "/s/"+meta.ID, nil)
	viewRec := httptest.NewRecorder()
	handler.ServeHTTP(viewRec, viewReq)
	if viewRec.Code != http.StatusOK {
		t.Fatalf("view status = %d, want %d", viewRec.Code, http.StatusOK)
	}
	if !strings.Contains(viewRec.Body.String(), `id="app"`) {
		t.Fatalf("expected scratch route to render SPA shell")
	}
}

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

	handler, store := newTestHandlerAndStore(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})
	meta, err := store.Create(t.Context(), strings.NewReader("expired body"), "text/plain", -time.Second)
	if err != nil {
		t.Fatalf("store.Create() error = %v", err)
	}

	viewReq := httptest.NewRequest(http.MethodGet, "/s/"+meta.ID, nil)
	viewRec := httptest.NewRecorder()
	handler.ServeHTTP(viewRec, viewReq)
	if viewRec.Code != http.StatusGone {
		t.Fatalf("view status = %d, want %d", viewRec.Code, http.StatusGone)
	}

	rawReq := httptest.NewRequest(http.MethodGet, "/api/raw/"+meta.ID, nil)
	rawRec := httptest.NewRecorder()
	handler.ServeHTTP(rawRec, rawReq)
	if rawRec.Code != http.StatusGone {
		t.Fatalf("raw status after lazy delete = %d, want %d", rawRec.Code, http.StatusGone)
	}
}

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

	handler, store := newTestHandlerAndStore(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})
	meta, err := store.Create(t.Context(), strings.NewReader("expired body"), "text/plain", -time.Second)
	if err != nil {
		t.Fatalf("store.Create() error = %v", err)
	}

	rawReq := httptest.NewRequest(http.MethodGet, "/api/raw/"+meta.ID, nil)
	rawRec := httptest.NewRecorder()
	handler.ServeHTTP(rawRec, rawReq)
	if rawRec.Code != http.StatusGone {
		t.Fatalf("raw status = %d, want %d", rawRec.Code, http.StatusGone)
	}
	if rawRec.Body.Len() != 0 {
		t.Fatalf("expected empty response body, got %q", rawRec.Body.String())
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	viewReq := httptest.NewRequest(http.MethodGet, "/s/does-not-exist", nil)
	viewRec := httptest.NewRecorder()
	handler.ServeHTTP(viewRec, viewReq)
	if viewRec.Code != http.StatusGone {
		t.Fatalf("view status = %d, want %d", viewRec.Code, http.StatusGone)
	}

	rawReq := httptest.NewRequest(http.MethodGet, "/api/raw/does-not-exist", nil)
	rawRec := httptest.NewRecorder()
	handler.ServeHTTP(rawRec, rawReq)
	if rawRec.Code != http.StatusGone {
		t.Fatalf("raw status = %d, want %d", rawRec.Code, http.StatusGone)
	}
	if rawRec.Body.Len() != 0 {
		t.Fatalf("expected empty response body, got %q", rawRec.Body.String())
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	viewReq := httptest.NewRequest(http.MethodGet, "/s/never-uploaded-id", nil)
	viewReq.RemoteAddr = "127.0.0.1:5095"
	viewRec := httptest.NewRecorder()
	handler.ServeHTTP(viewRec, viewReq)
	if viewRec.Code != http.StatusGone {
		t.Fatalf("view-never-uploaded status = %d, want %d", viewRec.Code, http.StatusGone)
	}

	rawReq := httptest.NewRequest(http.MethodGet, "/api/raw/never-uploaded-id", nil)
	rawReq.RemoteAddr = "127.0.0.1:5096"
	rawRec := httptest.NewRecorder()
	handler.ServeHTTP(rawRec, rawReq)
	if rawRec.Code != http.StatusGone {
		t.Fatalf("raw-never-uploaded status = %d, want %d", rawRec.Code, http.StatusGone)
	}
	if rawRec.Body.Len() != 0 {
		t.Fatalf("expected empty raw body for never-uploaded id, got %q", rawRec.Body.String())
	}

	metaReq := httptest.NewRequest(http.MethodGet, "/api/scratch/never-uploaded-id", nil)
	metaReq.RemoteAddr = "127.0.0.1:5097"
	metaRec := httptest.NewRecorder()
	handler.ServeHTTP(metaRec, metaReq)
	if metaRec.Code != http.StatusGone {
		t.Fatalf("metadata-never-uploaded status = %d, want %d", metaRec.Code, http.StatusGone)
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	req := httptest.NewRequest(http.MethodPost, "/api/scratch", strings.NewReader("not-multipart"))
	req.Header.Set("Content-Type", "multipart/form-data; boundary=missing")
	req.RemoteAddr = "127.0.0.1:5057"
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)
	if rec.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusBadRequest)
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024 * 1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	const uploads = 80

	type createdScratch struct {
		id   string
		body string
	}

	resultsCh := make(chan createdScratch, uploads)
	errCh := make(chan error, uploads)
	var wg sync.WaitGroup

	for i := 0; i < uploads; i++ {
		wg.Add(1)
		go func(i int) {
			defer wg.Done()

			body := fmt.Sprintf("parallel-upload-%03d-%s", i, strings.Repeat("x", i%17))
			createReq := httptest.NewRequest(http.MethodPost, "/api/scratch", bytes.NewBufferString(body))
			createReq.Header.Set("Content-Type", "text/plain; charset=utf-8")
			createReq.RemoteAddr = fmt.Sprintf("127.0.0.1:%d", 8200+i)
			createRec := httptest.NewRecorder()
			handler.ServeHTTP(createRec, createReq)
			if createRec.Code != http.StatusCreated {
				errCh <- fmt.Errorf("create status = %d, want %d", createRec.Code, http.StatusCreated)
				return
			}

			var payload map[string]any
			if err := json.Unmarshal(createRec.Body.Bytes(), &payload); err != nil {
				errCh <- fmt.Errorf("decode create payload error: %w", err)
				return
			}
			id, _ := payload["id"].(string)
			if id == "" {
				errCh <- fmt.Errorf("create payload missing id")
				return
			}

			metaReq := httptest.NewRequest(http.MethodGet, "/api/scratch/"+id, nil)
			metaRec := httptest.NewRecorder()
			handler.ServeHTTP(metaRec, metaReq)
			if metaRec.Code != http.StatusOK {
				errCh <- fmt.Errorf("metadata status = %d, want %d", metaRec.Code, http.StatusOK)
				return
			}

			rawReq := httptest.NewRequest(http.MethodGet, "/api/raw/"+id, nil)
			rawRec := httptest.NewRecorder()
			handler.ServeHTTP(rawRec, rawReq)
			if rawRec.Code != http.StatusOK {
				errCh <- fmt.Errorf("raw status = %d, want %d", rawRec.Code, http.StatusOK)
				return
			}
			if got := rawRec.Body.String(); got != body {
				errCh <- fmt.Errorf("raw body mismatch = %q, want %q", got, body)
				return
			}

			resultsCh <- createdScratch{id: id, body: body}
		}(i)
	}

	wg.Wait()
	close(resultsCh)
	close(errCh)
	for err := range errCh {
		t.Error(err)
	}

	seen := make(map[string]struct{}, uploads)
	for result := range resultsCh {
		if _, exists := seen[result.id]; exists {
			t.Errorf("duplicate scratch id generated: %s", result.id)
			continue
		}
		seen[result.id] = struct{}{}
	}
	if len(seen) != uploads {
		t.Fatalf("unique IDs = %d, want %d", len(seen), uploads)
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	const body = "parallel readers"
	createReq := httptest.NewRequest(http.MethodPost, "/api/scratch", bytes.NewBufferString(body))
	createReq.Header.Set("Content-Type", "text/plain; charset=utf-8")
	createReq.RemoteAddr = "127.0.0.1:6010"
	createRec := httptest.NewRecorder()
	handler.ServeHTTP(createRec, createReq)
	if createRec.Code != http.StatusCreated {
		t.Fatalf("create status = %d, want %d", createRec.Code, http.StatusCreated)
	}

	var payload map[string]any
	if err := json.Unmarshal(createRec.Body.Bytes(), &payload); err != nil {
		t.Fatalf("decode create payload error = %v", err)
	}
	id, _ := payload["id"].(string)
	if id == "" {
		t.Fatalf("create payload missing id")
	}

	paths := []string{
		"/api/raw/" + id,
		"/s/" + id,
		"/api/scratch/" + id,
	}
	const requests = 120

	errCh := make(chan error, requests)
	var wg sync.WaitGroup
	for i := 0; i < requests; i++ {
		wg.Add(1)
		go func(i int) {
			defer wg.Done()
			path := paths[i%len(paths)]
			req := httptest.NewRequest(http.MethodGet, path, nil)
			req.RemoteAddr = fmt.Sprintf("127.0.0.1:%d", 6100+i)
			rec := httptest.NewRecorder()
			handler.ServeHTTP(rec, req)

			if rec.Code != http.StatusOK {
				errCh <- fmt.Errorf("path %s status = %d, want %d", path, rec.Code, http.StatusOK)
				return
			}

			switch {
			case strings.HasPrefix(path, "/api/raw/"):
				if got := rec.Body.String(); got != body {
					errCh <- fmt.Errorf("raw body = %q, want %q", got, body)
				}
			case strings.HasPrefix(path, "/s/"):
				if !strings.Contains(rec.Body.String(), `id="app"`) {
					errCh <- fmt.Errorf("view body missing SPA marker")
				}
			case strings.HasPrefix(path, "/api/scratch/"):
				var gotPayload map[string]any
				if err := json.Unmarshal(rec.Body.Bytes(), &gotPayload); err != nil {
					errCh <- fmt.Errorf("metadata decode error: %w", err)
					return
				}
				if gotID, _ := gotPayload["id"].(string); gotID != id {
					errCh <- fmt.Errorf("metadata id = %q, want %q", gotID, id)
				}
			}
		}(i)
	}
	wg.Wait()
	close(errCh)
	for err := range errCh {
		t.Error(err)
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      80 * time.Millisecond,
		rateLimitEnable: false,
	})

	createReq := httptest.NewRequest(http.MethodPost, "/api/scratch", bytes.NewBufferString("expires soon"))
	createReq.Header.Set("Content-Type", "text/plain; charset=utf-8")
	createReq.RemoteAddr = "127.0.0.1:7010"
	createRec := httptest.NewRecorder()
	handler.ServeHTTP(createRec, createReq)
	if createRec.Code != http.StatusCreated {
		t.Fatalf("create status = %d, want %d", createRec.Code, http.StatusCreated)
	}

	var payload map[string]any
	if err := json.Unmarshal(createRec.Body.Bytes(), &payload); err != nil {
		t.Fatalf("decode create payload error = %v", err)
	}
	id, _ := payload["id"].(string)
	if id == "" {
		t.Fatalf("create payload missing id")
	}

	time.Sleep(130 * time.Millisecond)

	paths := []string{
		"/api/raw/" + id,
		"/s/" + id,
		"/api/scratch/" + id,
	}
	const requests = 90

	errCh := make(chan error, requests)
	var wg sync.WaitGroup
	for i := 0; i < requests; i++ {
		wg.Add(1)
		go func(i int) {
			defer wg.Done()
			path := paths[i%len(paths)]
			req := httptest.NewRequest(http.MethodGet, path, nil)
			req.RemoteAddr = fmt.Sprintf("127.0.0.1:%d", 7100+i)
			rec := httptest.NewRecorder()
			handler.ServeHTTP(rec, req)

			if rec.Code != http.StatusGone {
				errCh <- fmt.Errorf("expired path %s status = %d, want %d", path, rec.Code, http.StatusGone)
				return
			}

			if strings.HasPrefix(path, "/s/") && !strings.Contains(rec.Body.String(), `id="app"`) {
				errCh <- fmt.Errorf("expired view body missing SPA marker")
			}
		}(i)
	}
	wg.Wait()
	close(errCh)
	for err := range errCh {
		t.Error(err)
	}
}

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

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      time.Hour,
		rateLimitEnable: false,
	})

	req := httptest.NewRequest(http.MethodGet, "/this-path-does-not-exist", nil)
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusNotFound {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusNotFound)
	}
	if !strings.Contains(rec.Body.String(), `id="app"`) {
		t.Fatalf("unexpected not found body: %q", rec.Body.String())
	}
}

type testServerOptions struct {
	maxUploadBytes  int64
	defaultTTL      time.Duration
	rateLimitEnable bool
}

func newTestHandler(t *testing.T, opts testServerOptions) http.Handler {
	t.Helper()

	handler, _ := newTestHandlerAndStore(t, opts)
	return handler
}

func newTestHandlerAndStore(t *testing.T, opts testServerOptions) (http.Handler, *storage.FilesystemStore) {
	t.Helper()

	dataDir := filepath.Join(t.TempDir(), "data")
	store, err := storage.NewFilesystemStore(dataDir)
	if err != nil {
		t.Fatalf("NewFilesystemStore() error = %v", err)
	}

	cfg := config.Config{
		Server: config.ServerConfig{
			ListenAddr: ":0",
		},
		Limits: config.LimitsConfig{
			MaxUploadSizeBytes: opts.maxUploadBytes,
			DefaultTTLDuration: opts.defaultTTL,
			RawCacheMaxBytes:   64 * 1024 * 1024,
			RawCacheMaxEntries: 32,
		},
		Storage: config.StorageConfig{
			DataDir: dataDir,
		},
		Security: config.SecurityConfig{
			RateLimit: config.RateLimitConfig{
				Enabled:           opts.rateLimitEnable,
				RequestsPerMinute: 120,
				Burst:             1,
			},
		},
	}

	srv := &Server{
		cfg:      cfg,
		store:    store,
		logger:   log.New(io.Discard, "", 0),
		rawCache: newRawContentCache(cfg.Limits.RawCacheMaxEntries, cfg.Limits.RawCacheMaxBytes),
	}
	return srv.Routes(), store
}