package ovf

import (
	"fmt"
	"os"
	"strings"

	vboxcommon "github.com/mitchellh/packer/builder/virtualbox/common"
	"github.com/mitchellh/packer/common"
	"github.com/mitchellh/packer/packer"
)

// Config is the configuration structure for the builder.
type Config struct {
	common.PackerConfig             `mapstructure:",squash"`
	vboxcommon.ExportConfig         `mapstructure:",squash"`
	vboxcommon.ExportOpts           `mapstructure:",squash"`
	vboxcommon.FloppyConfig         `mapstructure:",squash"`
	vboxcommon.OutputConfig         `mapstructure:",squash"`
	vboxcommon.RunConfig            `mapstructure:",squash"`
	vboxcommon.SSHConfig            `mapstructure:",squash"`
	vboxcommon.ShutdownConfig       `mapstructure:",squash"`
	vboxcommon.VBoxManageConfig     `mapstructure:",squash"`
	vboxcommon.VBoxManagePostConfig `mapstructure:",squash"`
	vboxcommon.VBoxVersionConfig    `mapstructure:",squash"`

	BootCommand          []string `mapstructure:"boot_command"`
	SourcePath           string   `mapstructure:"source_path"`
	GuestAdditionsMode   string   `mapstructure:"guest_additions_mode"`
	GuestAdditionsPath   string   `mapstructure:"guest_additions_path"`
	GuestAdditionsURL    string   `mapstructure:"guest_additions_url"`
	GuestAdditionsSHA256 string   `mapstructure:"guest_additions_sha256"`
	VMName               string   `mapstructure:"vm_name"`
	ImportOpts           string   `mapstructure:"import_opts"`
	ImportFlags          []string `mapstructure:"import_flags"`

	tpl *packer.ConfigTemplate
}

func NewConfig(raws ...interface{}) (*Config, []string, error) {
	c := new(Config)
	md, err := common.DecodeConfig(c, raws...)
	if err != nil {
		return nil, nil, err
	}

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

	// Defaults
	if c.GuestAdditionsMode == "" {
		c.GuestAdditionsMode = "upload"
	}

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

	// Prepare the errors
	errs := common.CheckUnusedConfig(md)
	errs = packer.MultiErrorAppend(errs, c.ExportConfig.Prepare(c.tpl)...)
	errs = packer.MultiErrorAppend(errs, c.ExportOpts.Prepare(c.tpl)...)
	errs = packer.MultiErrorAppend(errs, c.FloppyConfig.Prepare(c.tpl)...)
	errs = packer.MultiErrorAppend(errs, c.OutputConfig.Prepare(c.tpl, &c.PackerConfig)...)
	errs = packer.MultiErrorAppend(errs, c.RunConfig.Prepare(c.tpl)...)
	errs = packer.MultiErrorAppend(errs, c.ShutdownConfig.Prepare(c.tpl)...)
	errs = packer.MultiErrorAppend(errs, c.SSHConfig.Prepare(c.tpl)...)
	errs = packer.MultiErrorAppend(errs, c.VBoxManageConfig.Prepare(c.tpl)...)
	errs = packer.MultiErrorAppend(errs, c.VBoxManagePostConfig.Prepare(c.tpl)...)
	errs = packer.MultiErrorAppend(errs, c.VBoxVersionConfig.Prepare(c.tpl)...)

	templates := map[string]*string{
		"guest_additions_mode":   &c.GuestAdditionsMode,
		"guest_additions_sha256": &c.GuestAdditionsSHA256,
		"source_path":            &c.SourcePath,
		"vm_name":                &c.VMName,
		"import_opts":            &c.ImportOpts,
	}

	for n, ptr := range templates {
		var err error
		*ptr, err = c.tpl.Process(*ptr, nil)
		if err != nil {
			errs = packer.MultiErrorAppend(
				errs, fmt.Errorf("Error processing %s: %s", n, err))
		}
	}

	sliceTemplates := map[string][]string{
		"import_flags": c.ImportFlags,
	}

	for n, slice := range sliceTemplates {
		for i, elem := range slice {
			var err error
			slice[i], err = c.tpl.Process(elem, nil)
			if err != nil {
				errs = packer.MultiErrorAppend(
					errs, fmt.Errorf("Error processing %s[%d]: %s", n, i, err))
			}
		}
	}

	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))
		}
	}

	for i, command := range c.BootCommand {
		if err := c.tpl.Validate(command); err != nil {
			errs = packer.MultiErrorAppend(errs,
				fmt.Errorf("Error processing boot_command[%d]: %s", i, err))
		}
	}

	validates := map[string]*string{
		"guest_additions_path": &c.GuestAdditionsPath,
		"guest_additions_url":  &c.GuestAdditionsURL,
	}

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

	validMode := false
	validModes := []string{
		vboxcommon.GuestAdditionsModeDisable,
		vboxcommon.GuestAdditionsModeAttach,
		vboxcommon.GuestAdditionsModeUpload,
	}

	for _, mode := range validModes {
		if c.GuestAdditionsMode == mode {
			validMode = true
			break
		}
	}

	if !validMode {
		errs = packer.MultiErrorAppend(errs,
			fmt.Errorf("guest_additions_mode is invalid. Must be one of: %v", validModes))
	}

	if c.GuestAdditionsSHA256 != "" {
		c.GuestAdditionsSHA256 = strings.ToLower(c.GuestAdditionsSHA256)
	}

	// 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
	}

	// TODO: Write a packer fix and just remove import_opts
	if c.ImportOpts != "" {
		c.ImportFlags = append(c.ImportFlags, "--options", c.ImportOpts)
	}

	return c, warnings, nil
}