package common

import (
	"errors"
	"fmt"
	"os"
	"time"

	"github.com/mitchellh/multistep"
	"github.com/mitchellh/packer/common"
	commonssh "github.com/mitchellh/packer/common/ssh"
	"github.com/mitchellh/packer/packer"
)

type CommonConfig struct {
	Username string `mapstructure:"remote_username"`
	Password string `mapstructure:"remote_password"`
	HostIp   string `mapstructure:"remote_host"`

	VMName      string   `mapstructure:"vm_name"`
	SrName      string   `mapstructure:"sr_name"`
	FloppyFiles []string `mapstructure:"floppy_files"`
	NetworkName string   `mapstructure:"network_name"`

	HostPortMin uint `mapstructure:"host_port_min"`
	HostPortMax uint `mapstructure:"host_port_max"`

	BootCommand     []string `mapstructure:"boot_command"`
	ShutdownCommand string   `mapstructure:"shutdown_command"`

	RawBootWait string `mapstructure:"boot_wait"`
	BootWait    time.Duration

	ToolsIsoName string `mapstructure:"tools_iso_name"`

	HTTPDir     string `mapstructure:"http_directory"`
	HTTPPortMin uint   `mapstructure:"http_port_min"`
	HTTPPortMax uint   `mapstructure:"http_port_max"`

	LocalIp string `mapstructure:"local_ip"`

	//	SSHHostPortMin    uint   `mapstructure:"ssh_host_port_min"`
	//	SSHHostPortMax    uint   `mapstructure:"ssh_host_port_max"`
	SSHKeyPath  string `mapstructure:"ssh_key_path"`
	SSHPassword string `mapstructure:"ssh_password"`
	//	SSHPort           uint   `mapstructure:"ssh_port"`
	SSHUser           string `mapstructure:"ssh_username"`
	RawSSHWaitTimeout string `mapstructure:"ssh_wait_timeout"`
	SSHWaitTimeout    time.Duration

	OutputDir string `mapstructure:"output_directory"`
	Format    string `mapstructure:"format"`
	KeepVM    string `mapstructure:"keep_vm"`
}

func (c *CommonConfig) Prepare(t *packer.ConfigTemplate, pc *common.PackerConfig) []error {
	var err error

	// Set default values

	if c.HostPortMin == 0 {
		c.HostPortMin = 5900
	}

	if c.HostPortMax == 0 {
		c.HostPortMax = 6000
	}

	if c.RawBootWait == "" {
		c.RawBootWait = "5s"
	}

	if c.ToolsIsoName == "" {
		c.ToolsIsoName = "xs-tools.iso"
	}

	if c.HTTPPortMin == 0 {
		c.HTTPPortMin = 8000
	}

	if c.HTTPPortMax == 0 {
		c.HTTPPortMax = 9000
	}

	if c.RawSSHWaitTimeout == "" {
		c.RawSSHWaitTimeout = "200m"
	}

	if c.FloppyFiles == nil {
		c.FloppyFiles = make([]string, 0)
	}

	/*
		if c.SSHHostPortMin == 0 {
			c.SSHHostPortMin = 2222
		}

		if c.SSHHostPortMax == 0 {
			c.SSHHostPortMax = 4444
		}

		if c.SSHPort == 0 {
			c.SSHPort = 22
		}
	*/

	if c.RawSSHWaitTimeout == "" {
		c.RawSSHWaitTimeout = "20m"
	}

	if c.OutputDir == "" {
		c.OutputDir = fmt.Sprintf("output-%s", pc.PackerBuildName)
	}

	if c.Format == "" {
		c.Format = "xva"
	}

	if c.KeepVM == "" {
		c.KeepVM = "never"
	}

	// Template substitution

	templates := map[string]*string{
		"remote_username":  &c.Username,
		"remote_password":  &c.Password,
		"remote_host":      &c.HostIp,
		"vm_name":          &c.VMName,
		"sr_name":          &c.SrName,
		"shutdown_command": &c.ShutdownCommand,
		"boot_wait":        &c.RawBootWait,
		"tools_iso_name":   &c.ToolsIsoName,
		"http_directory":   &c.HTTPDir,
		"local_ip":         &c.LocalIp,
		"ssh_key_path":     &c.SSHKeyPath,
		"ssh_password":     &c.SSHPassword,
		"ssh_username":     &c.SSHUser,
		"ssh_wait_timeout": &c.RawSSHWaitTimeout,
		"output_directory": &c.OutputDir,
		"format":           &c.Format,
		"keep_vm":          &c.KeepVM,
	}
	for i := range c.FloppyFiles {
		templates[fmt.Sprintf("floppy_files[%d]", i)] = &c.FloppyFiles[i]
	}

	errs := make([]error, 0)
	for n, ptr := range templates {
		*ptr, err = t.Process(*ptr, nil)
		if err != nil {
			errs = append(errs, fmt.Errorf("Error processing %s: %s", n, err))
		}
	}

	// Validation

	if c.Username == "" {
		errs = append(errs, errors.New("remote_username must be specified."))
	}

	if c.Password == "" {
		errs = append(errs, errors.New("remote_password must be specified."))
	}

	if c.HostIp == "" {
		errs = append(errs, errors.New("remote_host must be specified."))
	}

	if c.VMName == "" {
		errs = append(errs, errors.New("vm_name must be specified."))
	}

	if c.HostPortMin > c.HostPortMax {
		errs = append(errs, errors.New("the host min port must be less than the max"))
	}

	if c.HTTPPortMin > c.HTTPPortMax {
		errs = append(errs, errors.New("the HTTP min port must be less than the max"))
	}

	c.BootWait, err = time.ParseDuration(c.RawBootWait)
	if err != nil {
		errs = append(errs, fmt.Errorf("Failed to parse boot_wait: %s", err))
	}

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

	if c.SSHKeyPath != "" {
		if _, err := os.Stat(c.SSHKeyPath); err != nil {
			errs = append(errs, fmt.Errorf("ssh_key_path is invalid: %s", err))
		} else if _, err := commonssh.FileSigner(c.SSHKeyPath); err != nil {
			errs = append(errs, fmt.Errorf("ssh_key_path is invalid: %s", err))
		}
	}

	/*
		if c.SSHHostPortMin > c.SSHHostPortMax {
			errs = append(errs,
				errors.New("ssh_host_port_min must be less than ssh_host_port_max"))
		}
	*/

	if c.SSHUser == "" {
		errs = append(errs, errors.New("An ssh_username must be specified."))
	}

	c.SSHWaitTimeout, err = time.ParseDuration(c.RawSSHWaitTimeout)
	if err != nil {
		errs = append(errs, fmt.Errorf("Failed to parse ssh_wait_timeout: %s", err))
	}

	switch c.Format {
	case "xva", "vdi_raw":
	default:
		errs = append(errs, errors.New("format must be one of 'xva', 'vdi_raw'"))
	}

	switch c.KeepVM {
	case "always", "never", "on_success":
	default:
		errs = append(errs, errors.New("keep_vm must be one of 'always', 'never', 'on_success'"))
	}

	/*
	   if c.LocalIp == "" {
	       errs = append(errs, errors.New("A local IP visible to XenServer's mangement interface is required to serve files."))
	   }
	*/

	return errs
}

// steps should check config.ShouldKeepVM first before cleaning up the VM
func (c CommonConfig) ShouldKeepVM(state multistep.StateBag) bool {
	switch c.KeepVM {
	case "always":
		return true
	case "never":
		return false
	case "on_success":
		// only keep instance if build was successful
		_, cancelled := state.GetOk(multistep.StateCancelled)
		_, halted := state.GetOk(multistep.StateHalted)
		return !(cancelled || halted)
	default:
		panic(fmt.Sprintf("Unknown keep_vm value '%s'", c.KeepVM))
	}
}

func (config CommonConfig) GetSR(client XenAPIClient) (*SR, error) {
	if config.SrName == "" {
		// Find the default SR
		return client.GetDefaultSR()

	} else {
		// Use the provided name label to find the SR to use
		srs, err := client.GetSRByNameLabel(config.SrName)

		if err != nil {
			return nil, err
		}

		switch {
		case len(srs) == 0:
			return nil, fmt.Errorf("Couldn't find a SR with the specified name-label '%s'", config.SrName)
		case len(srs) > 1:
			return nil, fmt.Errorf("Found more than one SR with the name '%s'. The name must be unique", config.SrName)
		}

		return srs[0], nil
	}
}