Add Notes endpoints

Pinboard notes are basically bookmarks with text bodies. The API only
allows listing all or retrieving a singular notes, and the schema
between the two are incompatible. Using a single type anyways, the API
docs cover this well enough. The date format is unique and requires
another unmarshaler (NotesDate).

encoders.go

@@ -30,8 +30,21 @@ func (u UTCDate) MarshalText() ([]byte, error) {
 
 func (u *UTCDate) UnmarshalText(text []byte) error {
 	d, err := time.Parse("2006-01-02", string(text))
-
 	*u = UTCDate{d}
+	return err
+}
+
+type NotesDate struct {
+	time.Time
+}
+
+func (n NotesDate) MarshalText() ([]byte, error) {
+	s := n.UTC().Format("2006-01-02 15:04:05")
+	return []byte(s), nil
+}
 
+func (n *NotesDate) UnmarshalText(text []byte) error {
+	d, err := time.Parse("2006-01-02 15:04:05", string(text))
+	*n = NotesDate{d}
 	return err
 }

notes.go

@@ -0,0 +1,66 @@
+package pinboard
+
+import (
+	"encoding/xml"
+	"fmt"
+	"net/url"
+	"regexp"
+)
+
+type Notes struct {
+	XMLName xml.Name `xml:"notes"`
+	Notes   []Note   `xml:"note"`
+}
+
+type Note struct {
+	XMLName xml.Name  `xml:"note"`
+	ID      string    `xml:"id,attr"`
+	Title   string    `xml:"title"`
+	Hash    string    `xml:"hash"`
+	Created NotesDate `xml:"created_at"`
+	Updated NotesDate `xml:"updated_at"`
+	Length  int       `xml:"length"`
+	Text    string    `xml:"text"`
+}
+
+func (p *Pinboard) Notes() ([]Note, error) {
+	u, err := url.Parse(apiBase + "notes/list")
+	if err != nil {
+		return []Note{}, fmt.Errorf("Failed to parse Notes list API URL: %v", err)
+	}
+
+	resp, err := p.Get(u)
+	if err != nil {
+		return []Note{}, err
+	}
+
+	tmp, err := parseResponse(resp, &Notes{})
+	if err != nil {
+		return []Note{}, fmt.Errorf("Failed to parse Notes response: %v", err)
+	}
+	notes := tmp.(*Notes)
+	return notes.Notes, err
+}
+
+func (p *Pinboard) Note(noteID string) (Note, error) {
+	if m, _ := regexp.Match("[a-z0-9]{20}", []byte(noteID)); !m {
+		return Note{}, fmt.Errorf("Note ID must be a 20 character sha1 hash")
+	}
+
+	u, err := url.Parse(apiBase + "notes/" + noteID)
+	if err != nil {
+		return Note{}, fmt.Errorf("Failed to parse note URL: %v", err)
+	}
+
+	resp, err := p.Get(u)
+	if err != nil {
+		return Note{}, fmt.Errorf("Error getting note: %v", err)
+	}
+
+	tmp, err := parseResponse(resp, &Note{})
+	if err != nil {
+		return Note{}, fmt.Errorf("Failed to parse Note response: %v", err)
+	}
+	note := tmp.(*Note)
+	return *note, err
+}