package httpapi

import (
	"errors"
	"html/template"
	"io"
	"log"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"runtime"
	"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 TestIsLikelyText(t *testing.T) {
	t.Parallel()

	if !isLikelyText("text/plain; charset=utf-8", []byte{0x00}) {
		t.Fatalf("text/plain should be treated as text")
	}
	if !isLikelyText("application/json", []byte{0x00}) {
		t.Fatalf("application/json should be treated as text")
	}
	if isLikelyText("application/octet-stream", []byte{0xff, 0xfe, 0xfd}) {
		t.Fatalf("binary octet-stream should not be treated as text")
	}
	if !isLikelyText("", []byte("hello")) {
		t.Fatalf("utf8 payload should be treated as text")
	}
	if !isLikelyText("", nil) {
		t.Fatalf("empty payload should be treated as text")
	}
}

func TestNewServerLoadsTemplates(t *testing.T) {
	tmp := t.TempDir()
	store, err := storage.NewFilesystemStore(filepath.Join(tmp, "data"))
	if err != nil {
		t.Fatalf("NewFilesystemStore() error = %v", err)
	}
	cfg := config.Config{
		Limits: config.LimitsConfig{MaxUploadSizeBytes: 1024},
		Security: config.SecurityConfig{
			RateLimit: config.RateLimitConfig{Enabled: false},
		},
	}

	_, file, _, ok := runtime.Caller(0)
	if !ok {
		t.Fatal("runtime.Caller failed")
	}
	repoRoot := filepath.Clean(filepath.Join(filepath.Dir(file), "..", ".."))
	wd, err := os.Getwd()
	if err != nil {
		t.Fatalf("Getwd() error = %v", err)
	}
	if err := os.Chdir(repoRoot); err != nil {
		t.Fatalf("Chdir() error = %v", err)
	}
	defer func() {
		_ = os.Chdir(wd)
	}()

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

func TestNewServerTemplateErrorAndIndexError(t *testing.T) {
	tmp := t.TempDir()
	store, err := storage.NewFilesystemStore(filepath.Join(tmp, "data"))
	if err != nil {
		t.Fatalf("NewFilesystemStore() error = %v", err)
	}
	cfg := config.Config{
		Limits: config.LimitsConfig{MaxUploadSizeBytes: 1024},
		Security: config.SecurityConfig{
			RateLimit: config.RateLimitConfig{Enabled: false},
		},
	}
	wd, err := os.Getwd()
	if err != nil {
		t.Fatalf("Getwd() error = %v", err)
	}
	if err := os.Chdir(tmp); err != nil {
		t.Fatalf("Chdir() error = %v", err)
	}
	defer func() {
		_ = os.Chdir(wd)
	}()

	if _, err := NewServer(cfg, store, log.New(io.Discard, "", 0)); err == nil {
		t.Fatalf("expected NewServer() template parse error")
	}

	s := &Server{}
	func() {
		defer func() {
			if recover() == nil {
				t.Fatalf("expected panic when templates are nil")
			}
		}()
		rec := httptest.NewRecorder()
		req := httptest.NewRequest(http.MethodGet, "/", nil)
		s.index(rec, req)
	}()
}

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

	s := &Server{
		templates: template.New("empty"),
	}
	rec := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	s.index(rec, req)
	if rec.Code != http.StatusInternalServerError {
		t.Fatalf("index status = %d, want %d", rec.Code, http.StatusInternalServerError)
	}
}