package main

import (
	"bytes"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"testing"
)

var (
	testDir    = "testdata"
	goldenFile = "config.yaml.golden"
	outFile    = "config.yaml"

	binName = "dkl-dir2config"
)

/*
Build and run the code with default parameters and testdata
*/
func TestMain(m *testing.M) {
	fmt.Println("Building...")
	if runtime.GOOS == "windows" {
		binName += ".exe"
	}

	build := exec.Command("go", "build", "-o", filepath.Join(testDir, binName))
	if err := build.Run(); err != nil {
		fmt.Fprintf(os.Stderr, "Cannot build : %v", err)
		os.Exit(1)
	}

	fmt.Println("Running Tests...")
	result := m.Run()

	fmt.Println("Cleaning Up ... ")
	os.Remove(binName)
	os.Exit(result)
}

func TestRunMain(t *testing.T) {
	err := os.Chdir(testDir)
	if err != nil {
		t.Fatal(err)
	}

	t.Run("RunWithNoArgument", func(t *testing.T) {
		cmd := exec.Command("./" + binName)

		if err := cmd.Run(); err != nil {
			t.Fatal(err)
		}
	})
	t.Run("CompareOutputs", func(t *testing.T) {
		cmd := exec.Command("./"+binName, "-out", outFile)

		if err := cmd.Run(); err != nil {
			t.Fatal(err)
		}

		output, err := os.ReadFile(outFile)
		if err != nil {
			t.Fatal(err)
		}
		expected, err := os.ReadFile(goldenFile)
		if err != nil {
			t.Fatal(err)
		}
		if ret := bytes.Compare(output, expected); ret != 0 {
			t.Fatalf("Output (%v) of length %d is different than expected (%v) of length %d", outFile, len(output), goldenFile, len(expected))
		}
	})
}