package classes_test

import (
	"bytes"
	"context"
	"crypto/rand"
	"errors"
	"os"
	"os/exec"
	"strings"
	"testing"
	"time"
	"unicode/utf8"

	"git.golem15.com/jakub/sm-bm-plugin/classes"
	"git.golem15.com/jakub/sm-bm-plugin/internal/pdftest"
)

func TestPDFTextExtract(t *testing.T) {
	if _, err := exec.LookPath("pdftotext"); err != nil {
		t.Skip("pdftotext is not installed (poppler-utils)")
	}
	ctx := context.Background()
	dir := t.TempDir()
	pdf := classes.DefaultPDFText()
	pdf.TempDir = dir
	if pdf.Bin != "pdftotext" || pdf.Timeout != 60*time.Second || pdf.MaxBytes != 1<<20 {
		t.Errorf("DefaultPDFText = %+v, want pdftotext, 60 s, 1 MiB", pdf)
	}
	doc := pdftest.OnePage("Globalizacja i demokracja")

	text, truncated, err := pdf.Extract(ctx, bytes.NewReader(doc))
	if err != nil {
		t.Fatalf("Extract: %v", err)
	}
	if !strings.Contains(text, "Globalizacja i demokracja") || truncated {
		t.Errorf("Extract = %q truncated %v, want the phrase, not truncated", text, truncated)
	}

	small := pdf
	small.MaxBytes = 5
	text, truncated, err = small.Extract(ctx, bytes.NewReader(doc))
	if err != nil || !truncated || len(text) > 5 {
		t.Errorf("MaxBytes 5: %q truncated %v err %v, want at most 5 bytes and truncated", text, truncated, err)
	}

	junk := make([]byte, 4096)
	_, _ = rand.Read(junk)
	text, _, err = pdf.Extract(ctx, bytes.NewReader(junk))
	if err != nil || text != "" {
		t.Errorf("random bytes: %q err %v, want empty text and no error", text, err)
	}

	missing := pdf
	missing.Bin = "jz-bm-no-such-pdftotext"
	if _, _, err := missing.Extract(ctx, bytes.NewReader(doc)); !errors.Is(err, classes.ErrPDFToolMissing) {
		t.Errorf("missing binary: err %v, want ErrPDFToolMissing", err)
	}

	entries, err := os.ReadDir(dir)
	if err != nil {
		t.Fatal(err)
	}
	if len(entries) != 0 {
		t.Errorf("the temp dir holds %d files after extraction, want none", len(entries))
	}
	// A temp dir Extract creates itself is private to the app user.
	sub := pdf
	sub.TempDir = dir + "/sub"
	if _, _, err := sub.Extract(ctx, bytes.NewReader(doc)); err != nil {
		t.Fatal(err)
	}
	if info, err := os.Stat(sub.TempDir); err != nil || info.Mode().Perm() != 0o700 {
		t.Errorf("created temp dir: %v %v, want mode 0700", info, err)
	}

	for _, c := range []struct{ in, want string }{
		{"plain tekst", "plain tekst"},
		{"a\x00b\x00", "ab"},
		{"zażółć\xff\xfe gęślą", "zażółć gęślą"},
		{"cut \xc5", "cut "},
		{"", ""},
	} {
		got := classes.CleanExtractedText(c.in)
		if got != c.want || !utf8.ValidString(got) {
			t.Errorf("CleanExtractedText(%q) = %q, want %q", c.in, got, c.want)
		}
	}
}