8 // A range of episodes with a start and possibly without an end.
9 type EpisodeRange struct {
10 Type EpisodeType // Must be equal to both the Start and End types; if End is nil, must be equal to the Start type
11 Start *Episode // The start of the range
12 End *Episode // The end of the range; may be nil, which represents an endless range
15 func EpisodeToRange(ep *Episode) *EpisodeRange {
23 // Converts the EpisodeRange into AniDB API range format.
24 func (er *EpisodeRange) String() string {
25 return er.Format(er.scale())
28 func (er *EpisodeRange) Format(width int) string {
29 if er.Start == er.End || (er.End != nil && *(er.Start) == *(er.End)) {
30 return er.Start.Format(width)
34 return fmt.Sprintf("%s-", er.Start.Format(width))
36 return fmt.Sprintf("%s-%s", er.Start.Format(width), er.End.Format(width))
39 func (er *EpisodeRange) FormatLog(max int) string {
40 return er.Format(scale(max))
43 func (er *EpisodeRange) scale() int {
47 s, e := er.Start.scale(), er.End.scale()
54 func (er *EpisodeRange) Infinite() bool {
55 return er != nil && er.End == nil
58 // Returns a channel that can be used to iterate using for/range.
60 // If the EpisodeRange is infinite, then the channel is also infinite.
61 // The caller is allowed to close the channel in such case.
62 func (er *EpisodeRange) Episodes() chan Episode {
63 ch := make(chan Episode, 1)
64 if er == nil || er.Start == nil {
80 // we allow the caller to close the channel on infinite lists
81 defer func() { recover(); abort = true }()
90 for ; !abort && ep.Parts > 0 && ep.Number == start.Number; ep.IncPart() {
93 for ; !abort; ep.IncNumber() {
96 case start.Part == -1 && end.Part == -1:
97 for ; ep.Number <= end.Number; ep.IncNumber() {
100 case start.Parts > 0:
101 for ; ep.Number == start.Number; ep.IncPart() {
106 for ; ep.Number < end.Number; ep.IncNumber() {
112 for ; ep.Part <= end.Part; ep.IncPart() {
120 // If ec is an *Episode, returns true if the Episode is of the same type as the range
121 // and has a Number >= Start.Number; if End is defined, then the episode's Number must
122 // also be <= End.Number.
124 // If ec is an *EpisodeRange, returns true if they are both of the same type and
125 // the ec's Start.Number is >= this range's Start.Number;
126 // also returns true if this EpisodeRange is unbounded or if the ec is bounded
127 // and ec's End.Number is <= this range's End.Number.
129 // If ec is an EpisodeList, returns true if all listed EpisodeRanges are contained
130 // by this EpisodeRange.
132 // Returns false otherwise.
133 func (er *EpisodeRange) ContainsEpisodes(ec EpisodeContainer) bool {
137 if er.Start == nil || er.Start.Type != er.Type ||
138 (er.End != nil && er.End.Type != er.Type) {
139 panic("Invalid EpisodeRange used")
142 switch e := ec.(type) {
144 if e.Type == er.Type && e.Number >= er.Start.Number {
147 } else if e.Number <= er.End.Number {
152 if e.Type == er.Type {
153 if e.Start.Number >= er.Start.Number {
156 } else if e.End == nil {
157 return false // a finite set can't contain an infinite one
158 } else if e.End.Number <= er.End.Number {
164 for _, ec := range e {
165 if !er.ContainsEpisodes(ec) {
175 // Tries to merge a with b, returning a new *EpisodeRange that's
176 // a superset of both a and b.
178 // Returns nil if a and b don't intersect, or are not adjacent.
179 func (a *EpisodeRange) Merge(b *EpisodeRange) (c *EpisodeRange) {
181 c = &EpisodeRange{Type: a.Type}
184 case a.Start.Number == b.Start.Number:
186 case a.Start.Part < 0:
188 case b.Start.Part < 0:
190 case a.Start.Part <= b.Start.Part:
195 case a.Start.Number < b.Start.Number:
202 case a.End == nil || b.End == nil:
204 case a.End.Number == b.End.Number:
210 case a.End.Part >= b.End.Part:
215 case a.End.Number > b.End.Number:
224 // Check if the given range is not nil, has a defined start
225 // and, if it has an end, that the end ends after the start.
226 func (er *EpisodeRange) Valid() bool {
228 case er == nil, er.Start == nil:
232 case er.Start.Number < er.End.Number:
234 case er.Start.Number > er.End.Number:
236 case er.Start.Part <= er.End.Part:
243 // Simplifies the Start/End ranges if one contains the other.
244 // Sets the pointers to be identical if the range is modified.
246 // Modifies in-place, returns itself.
247 func (er *EpisodeRange) Simplify() *EpisodeRange {
249 case er.Start.ContainsEpisodes(er.End):
251 case er.End != nil && er.End.ContainsEpisodes(er.Start):
257 // Splits the range into one or two ranges, using the given
258 // Episode as the split point. The Episode is not included in
259 // the resulting ranges.
260 func (er *EpisodeRange) Split(ep *Episode) []*EpisodeRange {
261 if !er.ContainsEpisodes(ep) { // implies same type
262 return []*EpisodeRange{er}
265 return []*EpisodeRange{nil, nil}
282 case a.ContainsEpisodes(ep) && b.ContainsEpisodes(ep):
283 return []*EpisodeRange{nil, nil}
284 case a.ContainsEpisodes(ep):
290 if a.Number == b.Number && b.Parts > 0 {
299 return []*EpisodeRange{nil, r.Simplify()}
300 case b.ContainsEpisodes(ep):
306 if b.Number == a.Number {
310 } else if b.Part < 0 {
319 return []*EpisodeRange{r.Simplify(), nil}
346 return []*EpisodeRange{ra, rb}
350 // Returns true if both ranges are of the same type and
351 // have identical start/end positions
352 func (a *EpisodeRange) Equals(b *EpisodeRange) bool {
353 if a == b { // pointers to the same thing
356 if a == nil || b == nil {
360 if a.Type == b.Type {
361 if a.End == b.End || (a.End != nil && b.End != nil &&
362 a.End.Number == b.End.Number && a.End.Part == b.End.Part) {
363 if a.Start == b.Start || a.Start.Number == b.Start.Number && a.Start.Part == b.Start.Part {
371 // CORNER CASE: e.g. 1.3,2.0 (or 1.3,2) never touch,
372 // unless it's known that 1.3 is the last part.
373 func (a *EpisodeRange) touches(b *EpisodeRange) bool {
374 if a == nil || b == nil || a.Type != b.Type {
380 // log.Println("same pointers")
382 case a.Start == b.Start, a.End != nil && a.End == b.End:
383 // log.Println("share pointers")
389 // log.Println("both infinite")
392 case b.End.Number == a.Start.Number:
394 // either is whole, or parts are adjacent/overlap
395 case b.End.Part == -1, a.Start.Part == -1,
396 b.End.Part >= a.Start.Part-1:
397 // log.Printf("{ %s [} %s ...", b.End, a.Start)
400 // only if start of next range is whole or is first part
401 case b.End.Number == a.Start.Number-1 && a.Start.Part <= 0:
403 // end is whole, or is last part, or part count is unknown
404 case b.End.Part == -1, b.End.Parts == 0,
405 b.End.Part == b.End.Parts:
406 // log.Printf("{ %s }[ %s ...", b.End, a.Start)
409 case b.End.Number > a.Start.Number:
410 // log.Printf("{ %s [ } %s ...", b.End, a.Start)
416 case a.End.Number == b.Start.Number:
418 case a.End.Part == -1, b.Start.Part == -1,
419 a.End.Part >= b.Start.Part-1:
420 // log.Printf("[ %s {] %s ...", a.End, b.Start)
423 case a.End.Number == b.Start.Number-1 && b.Start.Part <= 0:
425 case a.End.Part == -1, a.End.Parts == 0,
426 a.End.Part == a.End.Parts:
427 // log.Printf("[ %s ]{ %s ...", a.End, b.Start)
430 case a.End.Number > b.Start.Number:
431 // log.Printf("[ %s { ] %s ...", a.End, b.Start)
435 case a.Start.Number == b.Start.Number:
438 // either is whole, or parts are immediately adjacent
439 case a.Start.Part == -1, b.Start.Part == -1,
440 a.Start.Part == b.Start.Part,
441 a.Start.Part == b.Start.Part-1,
442 a.Start.Part == b.Start.Part+1:
443 // log.Printf("[{ %s - %s ]}", a.End, b.Start)
446 case a.End.Number == b.End.Number:
448 case a.End.Part == -1, b.End.Part == -1,
449 a.End.Part == b.End.Part,
450 a.End.Part == b.End.Part-1,
451 a.End.Part == b.End.Part+1:
452 // log.Printf("{[ %s - %s }]", b.End, a.Start)
456 case a.End.Number < b.End.Number:
458 case a.End.Number == b.Start.Number:
460 case a.End.Part == -1, b.Start.Part == -1,
461 a.End.Part >= b.Start.Part-1:
462 // log.Printf("[ %s {] %s }", a.End, b.Start)
465 case a.End.Number == b.Start.Number-1 && b.Start.Part <= 0:
467 case a.End.Part == -1, a.End.Part == a.End.Parts-1,
468 a.End.Part == b.Start.Parts:
469 // log.Printf("[ %s ]{ %s }", a.End, b.Start)
472 case a.End.Number > b.Start.Number:
473 // log.Printf("[ %s { ] %s }", a.End, b.Start)
477 case b.End.Number < a.End.Number:
479 case b.End.Number == a.Start.Number:
481 case b.End.Part == -1, a.Start.Part == -1,
482 b.End.Part >= a.Start.Part-1:
483 // log.Printf("{ %s [} %s ]", b.End, a.Start)
486 case b.End.Number == a.Start.Number-1 && a.Start.Part <= 0:
488 case b.End.Part == -1, b.End.Part == b.End.Parts-1,
489 b.End.Part == b.End.Parts:
490 // log.Printf("{ %s }[ %s ]", b.End, a.Start)
493 case b.End.Number > a.Start.Number:
494 // log.Printf("{ %s [ } %s ]", b.End, a.Start)
501 // Parses a string in the AniDB API range format and converts into an EpisodeRange.
502 func ParseEpisodeRange(s string) *EpisodeRange {
503 parts := strings.Split(s, "-")
509 for i := range parts {
510 eps[i] = ParseEpisode(parts[i])
516 // Not an interval (just "epno") --
517 // convert into interval starting and ending in the same episode
522 if len(parts) > 1 && eps[1] != nil && eps[0].Type != eps[1].Type {
525 return &EpisodeRange{