package main

import (
	"bytes"
	"path/filepath"
	"strings"
	"testing"
)

func TestRunDwimPrintsLargestTreesFirst(t *testing.T) {
	// dwim scans its root, then prints the trees report, the larger of
	// two duplicate-tree pairs first, and ends by saying how to print
	// the report again.
	t.Setenv(databaseEnv, testDBPath(t))

	root := realTempDir(t)

	small := []string{
		filepath.Dir(writeFile(t, root, "small1/f.bin", pattern(1, 300))),
		filepath.Dir(writeFile(t, root, "small2/f.bin", pattern(1, 300))),
	}
	large := []string{
		filepath.Dir(writeFile(t, root, "large1/f.bin", pattern(2, 5000))),
		filepath.Dir(writeFile(t, root, "large2/f.bin", pattern(2, 5000))),
	}

	var stdout bytes.Buffer

	stderr := captureStderr(t)

	err := runDwim(t.Context(), root, &stdout)
	if err != nil {
		t.Fatalf("runDwim: %v; stderr: %s", err, stderr())
	}

	lines := strings.Split(strings.TrimSuffix(stdout.String(), "\n"), "\n")
	if len(lines) != 3 {
		t.Fatalf("stdout = %q, want a header and two groups",
			stdout.String())
	}

	wantFirst := large[0] + "\t" + large[1] + "\t1\t5000\t"
	if !strings.HasPrefix(lines[1], wantFirst) {
		t.Errorf("first group = %q, want it to start %q", lines[1], wantFirst)
	}

	wantSecond := small[0] + "\t" + small[1] + "\t1\t300\t"
	if !strings.HasPrefix(lines[2], wantSecond) {
		t.Errorf("second group = %q, want it to start %q",
			lines[2], wantSecond)
	}

	last := "\ndwim: run \"sfdupes trees\" to print this report again\n"
	if got := stderr(); !strings.HasSuffix(got, last) {
		t.Errorf("stderr = %q, want it to end %q", got, last)
	}
}

func TestRunDwimScanErrorPrintsNoReport(t *testing.T) {
	// A fatal scan error ends dwim before the report: a root that does
	// not exist fails the scan as it fails scan itself.
	t.Setenv(databaseEnv, testDBPath(t))

	missing := filepath.Join(realTempDir(t), "missing")

	var stdout bytes.Buffer

	stderr := captureStderr(t)

	err := runDwim(t.Context(), missing, &stdout)
	if err == nil {
		t.Fatal("runDwim on a missing root: error = nil, want it fatal")
	}

	if got := stdout.String(); got != "" {
		t.Errorf("stdout = %q, want no report", got)
	}

	if got := stderr(); strings.Contains(got, "trees:") ||
		strings.Contains(got, "dwim:") {
		t.Errorf("stderr = %q, want nothing from trees or dwim", got)
	}
}