ics - sections_alarm.go

     1  package ics
     2  
     3  import (
     4  	"errors"
     5  	"io"
     6  
     7  	"vimagination.zapto.org/parser"
     8  )
     9  
    10  type psuedoTokeniser []parser.Phrase
    11  
    12  func (p *psuedoTokeniser) GetPhrase() (parser.Phrase, error) {
    13  	if len(*p) == 0 {
    14  		return parser.Phrase{
    15  			Type: parser.PhraseError,
    16  			Data: nil,
    17  		}, io.ErrUnexpectedEOF
    18  	}
    19  	ph := (*p)[0]
    20  	*p = (*p)[1:]
    21  	return ph, nil
    22  }
    23  
    24  // AlarmType is an interface this is fulfilled by AlarmAudio, AlarmDisplay and
    25  // AlarmEmail
    26  type AlarmType interface {
    27  	section
    28  	Type() string
    29  }
    30  
    31  // Alarm is the encompassing type for the three alarm types
    32  type Alarm struct {
    33  	AlarmType
    34  }
    35  
    36  func (a *Alarm) decode(t tokeniser) error {
    37  	var pt psuedoTokeniser
    38  Loop:
    39  	for {
    40  		ph, err := t.GetPhrase()
    41  		if err != nil {
    42  			return err
    43  		}
    44  		pt = append(pt, ph)
    45  		switch ph.Data[0].Data {
    46  		case "BEGIN":
    47  			return ErrInvalidStructure
    48  		case "ACTION":
    49  			if a.AlarmType != nil {
    50  				return ErrInvalidStructure
    51  			}
    52  			switch ph.Data[len(ph.Data)-1].Data {
    53  			case "AUDIO":
    54  				a.AlarmType = new(AlarmAudio)
    55  			case "DISPLAY":
    56  				a.AlarmType = new(AlarmDisplay)
    57  			case "EMAIL":
    58  				a.AlarmType = new(AlarmEmail)
    59  			case "URI":
    60  				a.AlarmType = new(AlarmURI)
    61  			case "NONE":
    62  				a.AlarmType = new(AlarmNone)
    63  			}
    64  		case "END":
    65  			break Loop
    66  		}
    67  	}
    68  	if a.AlarmType == nil {
    69  		return ErrMissingAlarmAction
    70  	}
    71  	return a.AlarmType.decode(&pt)
    72  }
    73  
    74  func (a *Alarm) encode(w writer) {
    75  	w.WriteString("BEGIN:VALARM\r\n")
    76  	switch a.AlarmType.(type) {
    77  	case *AlarmAudio:
    78  		w.WriteString("ACTION:AUDIO\r\n")
    79  	case *AlarmDisplay:
    80  		w.WriteString("ACTION:DISPLAY\r\n")
    81  	case *AlarmEmail:
    82  		w.WriteString("ACTION:EMAIL\r\n")
    83  	case *AlarmURI:
    84  		w.WriteString("ACTION:URI\r\n")
    85  	case *AlarmNone:
    86  		w.WriteString("ACTION:NONE\r\n")
    87  	}
    88  	a.AlarmType.encode(w)
    89  	w.WriteString("END:VALARM\r\n")
    90  }
    91  
    92  func (a *Alarm) valid() error {
    93  	switch a.AlarmType.(type) {
    94  	case *AlarmAudio, *AlarmDisplay, *AlarmEmail, *AlarmURI, *AlarmNone:
    95  		return a.AlarmType.valid()
    96  	}
    97  	return ErrInvalidAlarm
    98  }
    99  
   100  // Type returns the type of the alarm "AUDIO"
   101  func (AlarmAudio) Type() string {
   102  	return "AUDIO"
   103  }
   104  
   105  // Type returns the type of the alarm "DISPLAY"
   106  func (AlarmDisplay) Type() string {
   107  	return "DISPLAY"
   108  }
   109  
   110  // Type returns the type of the alarm "EMAIL"
   111  func (AlarmEmail) Type() string {
   112  	return "EMAIL"
   113  }
   114  
   115  // Type returns the type of the alarm "URI"
   116  func (AlarmURI) Type() string {
   117  	return "URI"
   118  }
   119  
   120  // Type returns the type of the alarm "NONE"
   121  func (AlarmNone) Type() string {
   122  	return "NONE"
   123  }
   124  
   125  // Errors
   126  var (
   127  	ErrInvalidStructure   = errors.New("invalid structure")
   128  	ErrMissingAlarmAction = errors.New("missing alarm action")
   129  	ErrInvalidAlarm       = errors.New("invalid alarm type")
   130  )