package parser

import (
	"os"
	"os/exec"
	"path/filepath"
	"testing"
)

// fakePdftotext stands in for the real executable: what matters here is how it
// is put on disk, not what it does once there.
var fakePdftotext = []byte("#!/bin/sh\necho bundled\n")

// The bundled copy has to land somewhere it can be exec'd, and run.
func TestInstallBundledRuns(t *testing.T) {
	t.Setenv("XDG_CACHE_HOME", t.TempDir())
	path, err := installBundled(fakePdftotext)
	if err != nil {
		t.Fatal(err)
	}
	out, err := exec.Command(path).Output()
	if err != nil {
		t.Fatalf("run %s: %v", path, err)
	}
	if string(out) != "bundled\n" {
		t.Errorf("output %q", out)
	}
}

// A copy already in place is reused, but only once its contents check out: a
// write cut short by a killed process must not become what every later run
// trusts.
func TestInstallBundledReplacesADamagedCopy(t *testing.T) {
	t.Setenv("XDG_CACHE_HOME", t.TempDir())
	path, err := installBundled(fakePdftotext)
	if err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(path, fakePdftotext[:5], 0o755); err != nil {
		t.Fatal(err)
	}
	again, err := installBundled(fakePdftotext)
	if err != nil {
		t.Fatal(err)
	}
	if again != path {
		t.Errorf("reinstalled to %s, want %s", again, path)
	}
	if got, _ := os.ReadFile(path); string(got) != string(fakePdftotext) {
		t.Errorf("damaged copy kept: %q", got)
	}
}

// Each build's copy has its own name, so a newer binary never runs an older
// one's pdftotext left in the same cache.
func TestInstallBundledNamesByContent(t *testing.T) {
	t.Setenv("XDG_CACHE_HOME", t.TempDir())
	a, err := installBundled(fakePdftotext)
	if err != nil {
		t.Fatal(err)
	}
	b, err := installBundled(append([]byte(nil), "#!/bin/sh\necho newer\n"...))
	if err != nil {
		t.Fatal(err)
	}
	if a == b || filepath.Dir(a) != filepath.Dir(b) {
		t.Errorf("paths %s and %s, want two names in one directory", a, b)
	}
}

// Without -tags bundled, nothing is embedded and PATH decides, as before.
func TestUnbundledUsesPath(t *testing.T) {
	if len(bundledPdftotext) != 0 {
		t.Skip("built with -tags bundled")
	}
	if cmd, err := pdftotextCommand(); err != nil || cmd != "pdftotext" {
		t.Errorf("command = %q, %v; want pdftotext from PATH", cmd, err)
	}
}