tweets.go

// -*- tab-width: 4; -*-

package main

import (
	"bufio"
	"log"
	"regexp"
	"strings"
	"time"
)

type Tweeter struct {
	Nick string
	URL  string
}
type Tweet struct {
	Tweeter Tweeter
	Created time.Time
	Text    string
}

// typedef to be able to attach sort methods
type Tweets []Tweet

func (tweets Tweets) Len() int {
	return len(tweets)
}
func (tweets Tweets) Less(i, j int) bool {
	return tweets[i].Created.Before(tweets[j].Created)
}
func (tweets Tweets) Swap(i, j int) {
	tweets[i], tweets[j] = tweets[j], tweets[i]
}

func (tweets Tweets) Tags() map[string]int {
	tags := make(map[string]int)
	re := regexp.MustCompile(`#[-\w]+`)
	for _, tweet := range tweets {
		for _, tag := range re.FindAllString(tweet.Text, -1) {
			tags[strings.TrimLeft(tag, "#")]++
		}
	}
	return tags
}

func ParseFile(scanner *bufio.Scanner, tweeter Tweeter) Tweets {
	var tweets Tweets
	re := regexp.MustCompile(`^(.+?)(\s+)(.+)$`) // .+? is ungreedy
	for scanner.Scan() {
		line := scanner.Text()
		if line == "" {
			continue
		}
		if strings.HasPrefix(line, "#") {
			continue
		}
		parts := re.FindStringSubmatch(line)
		// "Submatch 0 is the match of the entire expression, submatch 1 the
		// match of the first parenthesized subexpression, and so on."
		if len(parts) != 4 {
			if debug {
				log.Printf("could not parse: '%s' (source:%s)\n", line, tweeter.URL)
			}
			continue
		}
		tweets = append(tweets,
			Tweet{
				Tweeter: tweeter,
				Created: ParseTime(parts[1]),
				Text:    parts[3],
			})
	}
	if err := scanner.Err(); err != nil {
		panic(err)
	}
	return tweets
}

func ParseTime(timestr string) time.Time {
	var tm time.Time
	var err error
	// Twtxt clients generally uses basically time.RFC3339Nano, but sometimes
	// there's a colon in the timezone, or no timezone at all.
	for _, layout := range []string{
		"2006-01-02T15:04:05.999999999Z07:00",
		"2006-01-02T15:04:05.999999999Z0700",
		"2006-01-02T15:04:05.999999999",
		"2006-01-02T15:04.999999999Z07:00",
		"2006-01-02T15:04.999999999Z0700",
		"2006-01-02T15:04.999999999",
	} {
		tm, err = time.Parse(layout, strings.ToUpper(timestr))
		if err != nil {
			continue
		} else {
			break
		}
	}
	if err != nil {
		return time.Unix(0, 0)
	}
	return tm
}