(* OF (post-1970) temporal cycle vocabulary. Both types are closed variants
   private to this rite: EF code cannot name them, and this rite cannot name
   EF's. Every boundary and rank rule cites its Missale Romanum editio typica
   tertia (2002) "Normae universales de anno liturgico et de calendario"
   paragraph ("Normae n. N") or Institutio Generalis Missalis Romani
   paragraph ("IGMR n. N") -- the SAME PDF (docs/research/of/missale-
   romanum-2002.pdf) carries both documents, independently numbered from 1,
   so a bare "n. N" is ambiguous; every citation in this rite module names
   which document it is. *)

(* Normae Titulus II ("De anni circulo"), sections II-VI, PRIMARY-SOURCE-
   VERIFIED against the 2002 typical edition (docs/research/of/
   missale-romanum-2002.pdf, pdftotext -layout, around extracted line 3660
   onward): the document's own six subsection headings under "De anni
   circulo" are "I. De Triduo paschali", "II. De tempore paschali", "III. De
   tempore Quadragesimae", "IV. De tempore Nativitatis", "V. De tempore
   Adventus", "VI. De tempore 'per annum'". FIVE of those six are literally
   called a "tempus" (season); the Triduum is deliberately NOT -- it is
   named only "Triduum paschale", never "tempus Tridui". That is a real
   textual signal, not an omission this module is working around: the
   Missal's own authors did not count the Triduum as one of the seasons a
   day's season vocabulary needs to name. Confirmed independently by the
   Missal's own Mass-propers structure (extracted lines ~7778, ~8480):
   "HEBDOMADA SANCTA" (the Lenten Holy Week propers) and "SACRUM TRIDUUM
   PASCHALE" are printed as two SEPARATE section headings, and neither is
   titled "tempus" either.

   This module therefore has FIVE seasons, matching the design's own
   prediction (2026-08-24-colitur-of-rite-module-design.md §4.2): [Advent],
   [Christmas], [Lent], [Easter], [Ordinary_time]. No [Septuagesima] (the
   1969/2002 reform abolished the pre-Lent season the EF's Vocab_ef still
   carries -- Normae's own season list has no seventh "de tempore
   Septuagesimae" section at all, confirmed by its absence here) and no
   [Passiontide] (EF's separate season for the two weeks before Easter; the
   2002 Normae's own n. 30 merges what used to be "Passion Sunday" and "Palm
   Sunday" into ONE day, "Dominica in palmis de Passione Domini", and folds
   it into Lent's own week numbering as week VI -- see [temporal_of.ml]'s own
   citation on this for the full argument).

   WHERE THE TRIDUUM'S OWN THREE DAYS LAND, given they get no season of
   their own: Normae n. 28, PRIMARY TEXT: "Tempus Quadragesimae decurrit a
   feria IV Cinerum ad Missam in Cena Domini EXCLUSIVE" -- Lent runs from Ash
   Wednesday up to (excluding) the evening Mass of the Lord's Supper. At
   colitur's own civil-day granularity (one season per [Date.t], never a
   sub-day boundary), that puts the WHOLE civil day of Holy Thursday inside
   Lent (the excluded boundary is the Mass itself, an event within that day,
   not the day's own start). Good Friday and Holy Saturday have no season of
   their own to fall back to either -- n. 22/23 fix Easter Time's own start
   at "dominica Resurrectionis" (Easter SUNDAY), not a day earlier -- so by
   the same "extend the last season through the Triduum's daytime, since the
   only actual Mass in that window (the Vigil) is textually already Easter"
   reasoning EF's own temporal_ef.ml already uses for its own Passiontide
   ("Holy Saturday stays in Passiontide: the Vigil is a night Mass"), Good
   Friday and Holy Saturday both stay [Lent] here too. Normae n. 30 gives
   this a SECOND, independent, and more direct textual anchor unavailable to
   EF's own analogous decision: "Dominicae huius temporis appellantur
   dominicae I, II, III, IV, V in Quadragesima. Dominica sexta, in qua
   initium sumit Hebdomada sancta, dicitur ... 'Dominica in palmis de
   Passione Domini'" -- the Sundays of THIS TIME [Lent] are called Sundays
   I-V in Lent; the SIXTH Sunday, ON WHICH HOLY WEEK BEGINS, is called
   [without dropping the 'Alleluia', a rubric not relevant here] "Palm
   Sunday of the Lord's Passion". Normae's OWN prose therefore states that
   Holy Week (Palm Sunday through the Vigil) IS Lent's own sixth week, not a
   thing outside Lent's own numbering -- confirmed against
   [temporal_of.ml]'s own [week] computation, which independently derives
   the identical result (Palm Sunday through Holy Saturday all fall in week
   6 of Lent by the ordinary Sunday-aligned [floor_div] formula, with no
   special case needed for the Triduum days at all) -- see that file for the
   arithmetic. *)
type season = Advent | Christmas | Lent | Easter | Ordinary_time [@@deriving sexp]

(* Normae Titulus I ("De diebus liturgicis"), and the Tabula dierum
   liturgicorum's own 13-entry table (extracted lines ~3926-3980), name FOUR
   graded celebrations throughout: "Sollemnitas" (entries 1-4), "Festum"
   (entries 5-8), "Memoria obligatoria" (entries 10-11) and "Memoria ad
   libitum" (entry 12) -- confirmed against the Calendarium Romanum
   Generale's own printed month tables (e.g. "IN EPIPHANIA DOMINI
   Sollemnitas", "S. Raimundi de Penyafort, presbyteri" [no grade word:
   Memoria ad libitum by the table's own footnote, "Quando non indicatur
   gradus celebrationis, fit Memoria ad libitum"], "Ss. Stephani,
   protomartyris Festum"), which uses these four words as its own grade
   column, verbatim, for every entry.

   A FIFTH constructor, [Feria], is added beyond those four for an ordinary
   weekday -- not a fifth grade on the same Sollemnitas-Festum-Memoria
   scale, but a categorically different thing: Normae n. 16 (Titulus I.IV,
   "De feriis") calls these days "feriae" and never applies any of the four
   grade-words to one, yet {!Colitur_kernel.Celebration.t} requires SOME
   [rank] on every day (the same reason EF's own Vocab_ef.rank carries a
   catch-all [Class4] for its own plain ferias, RG 91 entry 28). The Tabula
   itself confirms ferias are graded for PRECEDENCE without ever being
   promoted to one of the four celebration-grades: entry 2 lists "Feriae
   Hebdomadae sanctae, a feria II ad feriam V inclusive" and "Feria IV
   Cinerum" [Ash Wednesday] at the SAME table position as Christmas,
   Epiphany, Ascension and Pentecost -- an extremely privileged PRECEDENCE,
   yet the table's own word for these days stays "feria", never
   "sollemnitas". Entry 9 similarly places "Feriae Adventus a die 17 ad 24
   decembris inclusive" and "Feriae Quadragesimae" together with a
   THIRD kind of day (unnamed days within the Nativity octave), and entry 13
   is the catch-all for every other feria. All THREE entries use the same
   word, "feria" -- what differs between them is precedence-table position,
   not grade. Phase 1 (this module, {!Temporal_of.temporal}) therefore
   assigns [Feria] uniformly to every day carrying no graded celebration;
   which Tabula entry a given [Feria] day occupies (Ash-Wednesday-tier vs.
   Advent-17-24/Lenten-tier vs. ordinary) is a {!Colitur_kernel.Precedence
   .rules.band} table lookup left to Phase 2, read off the day's own season/
   date/weekday the same way EF's own [Precedence_ef.band] already
   distinguishes its RG 91 entry 2 Triduum ferias from its entry-28 ordinary
   ones without either of those two needing a DIFFERENT [Vocab_ef.rank]
   value -- see design 2026-08-24-colitur-of-rite-module-design.md §3, "No
   kernel change should be needed for the ranks themselves". *)
type rank = Sollemnitas | Festum | Memoria_obligatoria | Memoria_ad_libitum | Feria [@@deriving sexp]

let seasons = [ Advent; Christmas; Lent; Easter; Ordinary_time ]
let ranks = [ Sollemnitas; Festum; Memoria_obligatoria; Memoria_ad_libitum; Feria ]

let season_to_string = function
  | Advent -> "advent"
  | Christmas -> "christmas"
  | Lent -> "lent"
  | Easter -> "easter"
  | Ordinary_time -> "ordinary-time"

let season_of_string = function
  | "advent" -> Some Advent
  | "christmas" -> Some Christmas
  | "lent" -> Some Lent
  | "easter" -> Some Easter
  | "ordinary-time" -> Some Ordinary_time
  | _ -> None

(* No lectionary-legacy word to preserve (spec §4.4's reasoning for EF's own
   [Vocab_ef.season_slug_word] does not apply here -- OF has not been
   bootstrapped from any external lectionary key set yet), so this is simply
   [season_to_string] under a separate name, kept distinct only so a future
   real divergence does not force renaming every call site. *)
let season_slug_word = season_to_string

let rank_to_string = function
  | Sollemnitas -> "sollemnitas"
  | Festum -> "festum"
  | Memoria_obligatoria -> "memoria-obligatoria"
  | Memoria_ad_libitum -> "memoria-ad-libitum"
  | Feria -> "feria"

let rank_of_string = function
  | "sollemnitas" -> Some Sollemnitas
  | "festum" -> Some Festum
  | "memoria-obligatoria" -> Some Memoria_obligatoria
  | "memoria-ad-libitum" -> Some Memoria_ad_libitum
  | "feria" -> Some Feria
  | _ -> None

let vocab : (season, rank) Colitur_kernel.Vocab.t =
  { seasons; season_to_string; season_of_string; ranks; rank_to_string; rank_of_string }