package vagrant

import (
	"compress/flate"
	"fmt"
	"github.com/mitchellh/packer/common"
	"github.com/mitchellh/packer/packer"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"strconv"
	"strings"
)

type DigitalOceanBoxConfig struct {
	common.PackerConfig `mapstructure:",squash"`

	OutputPath          string `mapstructure:"output"`
	VagrantfileTemplate string `mapstructure:"vagrantfile_template"`
	CompressionLevel    string `mapstructure:"compression_level"`

	tpl *packer.ConfigTemplate
}

type DigitalOceanVagrantfileTemplate struct {
	Image  string ""
	Region string ""
}

type DigitalOceanBoxPostProcessor struct {
	config DigitalOceanBoxConfig
}

func (p *DigitalOceanBoxPostProcessor) Configure(rDigitalOcean ...interface{}) error {
	md, err := common.DecodeConfig(&p.config, rDigitalOcean...)
	if err != nil {
		return err
	}

	p.config.tpl, err = packer.NewConfigTemplate()
	if err != nil {
		return err
	}
	p.config.tpl.UserVars = p.config.PackerUserVars

	// Accumulate any errors
	errs := common.CheckUnusedConfig(md)

	validates := map[string]*string{
		"output":               &p.config.OutputPath,
		"vagrantfile_template": &p.config.VagrantfileTemplate,
		"compression_level":    &p.config.CompressionLevel,
	}

	for n, ptr := range validates {
		if err := p.config.tpl.Validate(*ptr); err != nil {
			errs = packer.MultiErrorAppend(
				errs, fmt.Errorf("Error parsing %s: %s", n, err))
		}
	}

	if errs != nil && len(errs.Errors) > 0 {
		return errs
	}

	return nil
}

func (p *DigitalOceanBoxPostProcessor) PostProcess(ui packer.Ui, artifact packer.Artifact) (packer.Artifact, bool, error) {
	// Determine the image and region...
	tplData := &DigitalOceanVagrantfileTemplate{}

	parts := strings.Split(artifact.Id(), ":")
	if len(parts) != 2 {
		return nil, false, fmt.Errorf("Poorly formatted artifact ID: %s", artifact.Id())
	}

	tplData.Region = parts[0]
	tplData.Image = parts[1]

	// Compile the output path
	outputPath, err := p.config.tpl.Process(p.config.OutputPath, &OutputPathTemplate{
		ArtifactId: artifact.Id(),
		BuildName:  p.config.PackerBuildName,
		Provider:   "digitalocean",
	})
	if err != nil {
		return nil, false, err
	}

	// Create a temporary directory for us to build the contents of the box in
	dir, err := ioutil.TempDir("", "packer")
	if err != nil {
		return nil, false, err
	}
	defer os.RemoveAll(dir)

	// Create the Vagrantfile from the template
	vf, err := os.Create(filepath.Join(dir, "Vagrantfile"))
	if err != nil {
		return nil, false, err
	}
	defer vf.Close()

	vagrantfileContents := defaultDigitalOceanVagrantfile
	if p.config.VagrantfileTemplate != "" {
		log.Printf("Using vagrantfile template: %s", p.config.VagrantfileTemplate)
		f, err := os.Open(p.config.VagrantfileTemplate)
		if err != nil {
			err = fmt.Errorf("error opening vagrantfile template: %s", err)
			return nil, false, err
		}
		defer f.Close()

		contents, err := ioutil.ReadAll(f)
		if err != nil {
			err = fmt.Errorf("error reading vagrantfile template: %s", err)
			return nil, false, err
		}

		vagrantfileContents = string(contents)
	}

	vagrantfileContents, err = p.config.tpl.Process(vagrantfileContents, tplData)
	if err != nil {
		return nil, false, fmt.Errorf("Error writing Vagrantfile: %s", err)
	}
	vf.Write([]byte(vagrantfileContents))
	vf.Close()

	// Create the metadata
	metadata := map[string]string{"provider": "digital_ocean"}
	if err := WriteMetadata(dir, metadata); err != nil {
		return nil, false, err
	}

	// Compress the directory to the given output path
	var level int = flate.DefaultCompression
	if p.config.CompressionLevel != "" {
		level, err = strconv.Atoi(p.config.CompressionLevel)
		if err != nil {
			return nil, false, err
		}
	}

	if err := DirToBox(outputPath, dir, ui, level); err != nil {
		err = fmt.Errorf("error creating box: %s", err)
		return nil, false, err
	}

	return NewArtifact("DigitalOcean", outputPath), true, nil
}

var defaultDigitalOceanVagrantfile = `
Vagrant.configure("2") do |config|
  config.vm.provider :digital_ocean do |digital_ocean|
	digital_ocean.image = "{{ .Image }}"
	digital_ocean.region = "{{ .Region }}"
  end
end

`