package pvm

import (
	"fmt"
	"os"

	parallelscommon "github.com/mitchellh/packer/builder/parallels/common"
	"github.com/mitchellh/packer/common"
	"github.com/mitchellh/packer/helper/config"
	"github.com/mitchellh/packer/packer"
	"github.com/mitchellh/packer/template/interpolate"
)

// Config is the configuration structure for the builder.
type Config struct {
	common.PackerConfig                 `mapstructure:",squash"`
	parallelscommon.FloppyConfig        `mapstructure:",squash"`
	parallelscommon.OutputConfig        `mapstructure:",squash"`
	parallelscommon.PrlctlConfig        `mapstructure:",squash"`
	parallelscommon.PrlctlVersionConfig `mapstructure:",squash"`
	parallelscommon.RunConfig           `mapstructure:",squash"`
	parallelscommon.SSHConfig           `mapstructure:",squash"`
	parallelscommon.ShutdownConfig      `mapstructure:",squash"`
	parallelscommon.ToolsConfig         `mapstructure:",squash"`

	BootCommand []string `mapstructure:"boot_command"`
	SourcePath  string   `mapstructure:"source_path"`
	VMName      string   `mapstructure:"vm_name"`
	ReassignMac bool     `mapstructure:"reassign_mac"`

	ctx interpolate.Context
}

func NewConfig(raws ...interface{}) (*Config, []string, error) {
	c := new(Config)
	err := config.Decode(&c, &config.DecodeOpts{
		Interpolate: true,
		InterpolateFilter: &interpolate.RenderFilter{
			Exclude: []string{
				"boot_command",
				"prlctl",
				"parallel_tools_guest_path",
			},
		},
	}, raws...)
	if err != nil {
		return nil, nil, err
	}

	if c.VMName == "" {
		c.VMName = fmt.Sprintf("packer-%s-{{timestamp}}", c.PackerBuildName)
	}

	// Prepare the errors
	var errs *packer.MultiError
	errs = packer.MultiErrorAppend(errs, c.FloppyConfig.Prepare(&c.ctx)...)
	errs = packer.MultiErrorAppend(errs, c.OutputConfig.Prepare(&c.ctx, &c.PackerConfig)...)
	errs = packer.MultiErrorAppend(errs, c.PrlctlConfig.Prepare(&c.ctx)...)
	errs = packer.MultiErrorAppend(errs, c.PrlctlVersionConfig.Prepare(&c.ctx)...)
	errs = packer.MultiErrorAppend(errs, c.RunConfig.Prepare(&c.ctx)...)
	errs = packer.MultiErrorAppend(errs, c.ShutdownConfig.Prepare(&c.ctx)...)
	errs = packer.MultiErrorAppend(errs, c.SSHConfig.Prepare(&c.ctx)...)
	errs = packer.MultiErrorAppend(errs, c.ToolsConfig.Prepare(&c.ctx)...)

	if c.SourcePath == "" {
		errs = packer.MultiErrorAppend(errs, fmt.Errorf("source_path is required"))
	} else {
		if _, err := os.Stat(c.SourcePath); err != nil {
			errs = packer.MultiErrorAppend(errs,
				fmt.Errorf("source_path is invalid: %s", err))
		}
	}

	// Warnings
	var warnings []string
	if c.ShutdownCommand == "" {
		warnings = append(warnings,
			"A shutdown_command was not specified. Without a shutdown command, Packer\n"+
				"will forcibly halt the virtual machine, which may result in data loss.")
	}

	// Check for any errors.
	if errs != nil && len(errs.Errors) > 0 {
		return nil, warnings, errs
	}

	return c, warnings, nil
}