package build

import (
	"bufio"
	"os"
	"path/filepath"

	"git.akyoto.dev/cli/q/src/compiler"
	"git.akyoto.dev/cli/q/src/elf"
)

// Build describes a compiler build.
type Build struct {
	Directory       string
	WriteExecutable bool
}

// New creates a new build.
func New(directory string) *Build {
	return &Build{
		Directory:       directory,
		WriteExecutable: true,
	}
}

// Run parses the input files and generates an executable file.
func (build *Build) Run() error {
	functions, err := compiler.Compile(build.Directory)

	if err != nil {
		return err
	}

	if !build.WriteExecutable {
		return nil
	}

	code, data := compiler.Finalize(functions)
	return writeToDisk(build.Executable(), code, data)
}

// Executable returns the path to the executable.
func (build *Build) Executable() string {
	return filepath.Join(build.Directory, filepath.Base(build.Directory))
}

// writeToDisk writes the executable file to disk.
func writeToDisk(filePath string, code []byte, data []byte) error {
	file, err := os.Create(filePath)

	if err != nil {
		return err
	}

	buffer := bufio.NewWriter(file)
	executable := elf.New(code, data)
	executable.Write(buffer)
	buffer.Flush()

	err = file.Close()

	if err != nil {
		return err
	}

	return os.Chmod(filePath, 0755)
}