package api

import (
	"bytes"
	"net/http/httptest"
	"net/url"
	"os"
	"path/filepath"
	"testing"

	"hamlab/internal/files"
)

// A file read answers Range requests — what a <video> needs to seek — and HEAD, through
// the same handler that streams everything else.
func TestFilesReadRanges(t *testing.T) {
	dir := t.TempDir()
	p := filepath.Join(dir, "clip.mp4")
	data := make([]byte, 10000)
	for i := range data {
		data[i] = byte(i % 251)
	}
	if err := os.WriteFile(p, data, 0o644); err != nil {
		t.Fatal(err)
	}
	s := &Server{fsLocal: files.Local{}}
	get := func(method, extra string, hdr map[string]string) *httptest.ResponseRecorder {
		r := httptest.NewRequest(method, "/api/files/read?path="+url.QueryEscape(p)+extra, nil)
		for k, v := range hdr {
			r.Header.Set(k, v)
		}
		w := httptest.NewRecorder()
		s.filesRead(w, r)
		return w
	}
	w := get("GET", "", nil)
	if w.Code != 200 || w.Body.Len() != 10000 || w.Header().Get("Content-Type") != "video/mp4" || w.Header().Get("Accept-Ranges") != "bytes" {
		t.Fatalf("whole: %d %d %q %q", w.Code, w.Body.Len(), w.Header().Get("Content-Type"), w.Header().Get("Accept-Ranges"))
	}
	w = get("GET", "", map[string]string{"Range": "bytes=100-199"})
	if w.Code != 206 || w.Header().Get("Content-Range") != "bytes 100-199/10000" || w.Body.Len() != 100 || w.Body.Bytes()[0] != data[100] {
		t.Fatalf("range: %d %q %d", w.Code, w.Header().Get("Content-Range"), w.Body.Len())
	}
	w = get("GET", "", map[string]string{"Range": "bytes=9990-"})
	if w.Code != 206 || w.Body.Len() != 10 || w.Body.Bytes()[9] != data[9999] {
		t.Fatalf("tail range: %d %d", w.Code, w.Body.Len())
	}
	w = get("HEAD", "", nil)
	if w.Code != 200 || w.Body.Len() != 0 || w.Header().Get("Content-Length") != "10000" {
		t.Fatalf("head: %d %d %q", w.Code, w.Body.Len(), w.Header().Get("Content-Length"))
	}
	if w := get("GET", "&max=50", nil); w.Code != 413 {
		t.Fatalf("the editor's cap: %d", w.Code)
	}
	if w := get("GET", "", map[string]string{"Range": "bytes=20000-"}); w.Code != 416 {
		t.Fatalf("a range past the end: %d", w.Code)
	}
	if err := os.Chmod(p, 0); err == nil && os.Geteuid() != 0 {
		if w := get("GET", "", nil); w.Code != 403 {
			t.Fatalf("unreadable: %d", w.Code)
		}
	}
}

// A write over the cap is refused whole: the file is not truncated first.
func TestFilesWriteCap(t *testing.T) {
	p := filepath.Join(t.TempDir(), "f.txt")
	if err := os.WriteFile(p, []byte("keep me"), 0o644); err != nil {
		t.Fatal(err)
	}
	s := &Server{fsLocal: files.Local{}}
	body := make([]byte, 8<<20+1)
	r := httptest.NewRequest("PUT", "/api/files/write?path="+url.QueryEscape(p), bytes.NewReader(body))
	w := httptest.NewRecorder()
	s.filesWrite(w, r)
	if w.Code != 413 {
		t.Fatalf("got %d", w.Code)
	}
	if b, _ := os.ReadFile(p); string(b) != "keep me" {
		t.Fatalf("the file was touched: %q", b)
	}
	r = httptest.NewRequest("PUT", "/api/files/write?path="+url.QueryEscape(p), bytes.NewReader([]byte("new")))
	w = httptest.NewRecorder()
	s.filesWrite(w, r)
	if b, _ := os.ReadFile(p); w.Code != 204 || string(b) != "new" {
		t.Fatalf("a write within the cap: %d %q", w.Code, b)
	}
}

// A link to nothing is a 404, not an empty 200.
func TestFilesReadDanglingLink(t *testing.T) {
	dir := t.TempDir()
	l := filepath.Join(dir, "broken")
	if err := os.Symlink("nowhere", l); err != nil {
		t.Fatal(err)
	}
	s := &Server{fsLocal: files.Local{}}
	r := httptest.NewRequest("GET", "/api/files/read?path="+url.QueryEscape(l), nil)
	w := httptest.NewRecorder()
	s.filesRead(w, r)
	if w.Code != 404 {
		t.Fatalf("got %d: %s", w.Code, w.Body.String())
	}
}