package main

import (

	"bytes"

	"encoding/json"

	"fmt"

	"io"

	"os/exec"

	"github.com/osbuild/osbuild-composer/internal/distro"

	osbuild "github.com/osbuild/osbuild-composer/internal/osbuild1"

)

// Run an instance of osbuild, returning a parsed osbuild.Result.

//

// Note that osbuild returns non-zero when the pipeline fails. This function

// does not return an error in this case. Instead, the failure is communicated

// with its corresponding logs through osbuild.Result.

func RunOSBuild(manifest distro.Manifest, store, outputDirectory string, exports []string, errorWriter io.Writer) (*osbuild.Result, error) {

	cmd := exec.Command(

		"osbuild",

		"--store", store,

		"--output-directory", outputDirectory,

		"--json", "-",

	)

	for _, export := range exports {

		cmd.Args = append(cmd.Args, "--export", export)

	}

	cmd.Stderr = errorWriter

	stdin, err := cmd.StdinPipe()

	if err != nil {

		return nil, fmt.Errorf("error setting up stdin for osbuild: %v", err)

	}

	var stdoutBuffer bytes.Buffer

	cmd.Stdout = &stdoutBuffer

	err = cmd.Start()

	if err != nil {

		return nil, fmt.Errorf("error starting osbuild: %v", err)

	}

	err = json.NewEncoder(stdin).Encode(manifest)

	if err != nil {

		return nil, fmt.Errorf("error encoding osbuild pipeline: %v", err)

	}

	err = stdin.Close()

	if err != nil {

		return nil, fmt.Errorf("error closing osbuild's stdin: %v", err)

	}

	err = cmd.Wait()

	// try to decode the output even though the job could have failed

	var result osbuild.Result

	decodeErr := json.Unmarshal(stdoutBuffer.Bytes(), &result)

	if decodeErr != nil {

		return nil, fmt.Errorf("error decoding osbuild output: %v\nthe raw output:\n%s", decodeErr, stdoutBuffer.String())

	}

	if err != nil {

		// ignore ExitError if output could be decoded correctly

		if _, isExitError := err.(*exec.ExitError); !isExitError {

			return nil, fmt.Errorf("running osbuild failed: %v", err)

		}

	}

	return &result, nil

}