(* RG 475-476, the Creed -- see lib/rites/rite_ef/rubrics_ef.ml for the
   rubric quoted in full and every branch's own citation.

   One end-to-end test per clause of 475, plus a 476 negative, resolved
   against REAL calendar dates through the shipped sanctoral data (the same
   pipeline `colitur day`/`colitur rubrics` use) -- every expected value
   below was derived from the rubric's own text and checked against
   `colitur day <year>`'s real output (slug/rank/subject/weekday) BEFORE
   this module existed, never read off [Rubrics_ef.creed]'s own answer.
   Two synthetic unit tests isolate Trap One (RG 475(a) reads [temporal],
   never [observed]) directly, without depending on finding a real-calendar
   coincidence. *)

module Cal = Colitur_kernel.Calendar
module LD = Colitur_kernel.Liturgical_day
module Date = Colitur_kernel.Date
module Cel = Colitur_kernel.Celebration
module Colour = Colitur_kernel.Colour
module Subject = Colitur_kernel.Subject
module Slug = Colitur_kernel.Slug
module Temporal = Colitur_kernel.Temporal
module V = Rite_ef.Vocab_ef
module RE = Rite_ef.Rubrics_ef

let mk y m d = match Date.make ~year:y ~month:m ~day:d with Ok t -> t | Error e -> failwith e

(* Loaded once, module-level: every test below is a lookup against the same
   shipped calendar, and {!Cal.day} recomputes its whole liturgical year on
   every call (calendar.mli's own documented cost), so at minimum the layer
   itself should not be reloaded and re-merged per test case. *)
let layer =
  match Test_support.load_ef_layer () with Ok l -> l | Error e -> Alcotest.failf "%s" e

let ctx = Test_support.ef_context ()

let creed_on y m d = (Cal.day ctx layer (mk y m d)).LD.creed

let check name y m d expected = Alcotest.(check bool) name expected (creed_on y m d)

(* ---- RG 475(a): "in qualibet dominica, etsi eius Officium alicui festo
   locum cedat" ---- *)

let test_475a_ordinary_sunday () =
  (* 2026-01-25: an ordinary Time-after-Epiphany Sunday, Class2, green,
     "Dominica III post Epiphaniam" -- confirmed via `colitur day 2026`,
     no other clause of 475 could apply (Class2, subject Temporal, no
     octave, no apostle/vigil slug), so [true] here can only come from
     475(a) itself. *)
  check "475(a): an ordinary Sunday" 2026 1 25 true

(* Trap One, isolated directly: RG 475(a)'s own "ETSI EIUS OFFICIUM ALICUI
   FESTO LOCUM CEDAT" -- even when a feast has displaced the Sunday's own
   office, the Creed is still said. [observed] below is deliberately shaped
   so that NONE of 475(b)/(c)/(e) can produce [true] on their own (Class3,
   subject Saint, a slug on no list this module knows); the only way
   [creed] can return [true] is by reading [temporal]'s own [weekday],
   never [observed]. The synthetic [date] (an ordinary July day, itself a
   Wednesday in 2026) is chosen so nothing about the DATE itself suggests
   a Sunday either -- proving the function reads [temporal.weekday], not
   [Date.weekday date]. *)
let impeded_observed =
  Cel.make ~slug:(Slug.of_string_exn "some-impeding-feast-of-the-lord") ~rank:V.Class3
    ~status:Cel.Feast ~colour:Colour.Red ~subject:Subject.Saint ~layer:"synthetic" ()

let synthetic_temporal ~weekday : (V.season, V.rank) Temporal.t =
  { Temporal.season = V.Time_after_pentecost; week = Some 1; weekday; office = impeded_observed }

let test_475a_reads_temporal_not_observed () =
  Alcotest.(check bool) "Sunday-shaped [temporal] overrides a non-Sunday-shaped [observed]" true
    (RE.creed ~temporal:(synthetic_temporal ~weekday:Date.Sun) ~observed:impeded_observed
       ~date:(mk 2026 7 1));
  Alcotest.(check bool) "same [observed], non-Sunday [temporal]: false" false
    (RE.creed ~temporal:(synthetic_temporal ~weekday:Date.Wed) ~observed:impeded_observed
       ~date:(mk 2026 7 1))

(* ---- RG 475(b): "in festis I classis" ---- *)

let test_475b_class1_feast () =
  (* 2026-08-15: the Assumption, Class1. *)
  check "475(b): a I-class feast" 2026 8 15 true

(* ---- RG 475(c): "in festis II classis Domini et B. Mariae Virg." ---- *)

let test_475c_lord () =
  (* 2026-09-14: Exaltation of the Holy Cross, Class2, subject Lord. *)
  check "475(c): a II-class feast of the Lord" 2026 9 14 true

let test_475c_bvm_via_marian_slugs () =
  (* 2026-08-22: Immaculate Heart of Mary, Class2 -- ships [subject =
     Saint] in data/ef/sanctoral.sexp (confirmed by grep), so this can only
     come out [true] via {!Rite_ef.Precedence_ef.marian_slugs}, not via
     [subject = Bvm]. Also carries a real commemoration
     (+sts-timothy-hippolytus-and-symphorianus-martyrs), a live instance of
     476(e): the commemoration plays no part in this answer. *)
  check "475(c): a II-class BVM feast (via marian_slugs, subject=Saint in the data)" 2026 8 22 true

(* ---- RG 475(d): "per octavas Nativitatis Domini, Paschatis et
   Pentecostes, etiam in festis occurrentibus et in Missis votivis" ---- *)

let test_475d_octave_even_occurring_feast () =
  (* 2026-12-26: St Stephen, Class2, "S. Stephani Protomartyris" -- a real
     saint's feast OCCURRING within the Octave of the Nativity (RG 67's own
     "Com. octavae Nativitatis", carried as +ef-nativity-octave-day-2 in
     colitur's own commemoration). RG 475(d)'s own "etiam in festis
     occurrentibus" is written for exactly this shape: the Creed is said
     regardless. (This is the one place this suite deliberately diverges
     from the task brief's own worked example, which expected [false] here
     -- the brief mis-cited 26 December as 476(b)'s "plain II-class feast"
     case, missing that RG 475(d) explicitly overrides 476(b) inside the
     Nativity octave; see the task report.) *)
  check "475(d): a saint's feast occurring within the Nativity octave" 2026 12 26 true

let test_475d_octave_day_boundary () =
  (* 2026-01-01: the Octave Day of the Nativity itself (Circumcision),
     Class1 -- also [true] via 475(b) alone, kept as a boundary check that
     1 January is correctly included in the 8-day window. *)
  check "475(d): 1 January, the Octave Day of the Nativity" 2026 1 1 true

(* ---- RG 475(e): "in festis nataliciis Apostolorum et Evangelistarum,
   necnon in festis Cathedrae S. Petri et S. Barnabae Ap." ---- *)

let test_475e_apostle_natalicium () =
  (* 2026-11-30: St Andrew, Class2, subject Saint -- not covered by 475(c)
     (not Domini/BVM), so [true] here can only come from 475(e)'s own
     natalicia list. Also carries a real commemoration
     (+ef-advent-1-monday), another live 476(e) instance. *)
  check "475(e): an Apostle's own natalicium (Andrew)" 2026 11 30 true

let test_475e_barnabas_named_explicitly () =
  (* 2026-06-11: St Barnabas, Class3 -- named explicitly by the clause
     ("S. Barnabae Ap."); at Class3 it could not reach [true] via 475(b) or
     (c) regardless. *)
  check "475(e): St Barnabas, named explicitly" 2026 6 11 true

let test_475e_chair_of_peter_named_explicitly () =
  (* 2027-02-22 (NOT 2026: Feb 22 2026 is impeded by Lent I Sunday, so the
     Chair is not observed that year -- checked via `colitur day 2026`
     before picking 2027 instead): the Chair of St Peter, Class2, subject
     Saint -- NOT a natalicium (Peter's own is 29 June, shared with Paul),
     so [true] here can only come from the clause's own explicit "Cathedrae
     S. Petri" naming, not from the natalicium reading in general. *)
  check "475(e): the Chair of St Peter, named explicitly (not a natalicium)" 2027 2 22 true

let test_475e_excludes_conversion_of_paul () =
  (* Trap Two, directly: 2027-01-25, the Conversion of St Paul, Class3 --
     names an Apostle but is NOT his natalicium (his own is 29 June, with
     Peter); Class3 rules out 475(b)/(c), and this slug is deliberately
     absent from [creed_apostle_slugs]. Picked 2027 for the same impeded-
     Sunday reason as the Chair of Peter above (25 January 2026 is itself a
     Sunday). *)
  check "475(e) does NOT cover the Conversion of St Paul (not a natalicium)" 2027 1 25 false

(* ---- RG 23 (feriae) / RG 476(a): Ash Wednesday, Holy Week's own feriae,
   the Chrism/Lord's Supper Mass, the Easter Vigil Mass ---- *)

let test_ash_wednesday_no_creed () =
  check "RG 23(a)/476: Ash Wednesday, a I-class FERIA, not a festum" 2026 2 18 false

let test_holy_thursday_no_creed () =
  (* 2026-04-02: "Feria V in Cena Domini" -- RG 23(b)'s own "omnes feriae
     Hebdomadae sanctae"; also explicitly named by 476(a) ("sive... in
     Cena Domini"). *)
  check "RG 23(b)/476(a): Holy Thursday (Mass of the Lord's Supper)" 2026 4 2 false

let test_holy_saturday_easter_vigil_no_creed () =
  (* 2026-04-04: "Sabbato sanctum" -- RG 23(b) again; also explicitly named
     by 476(a) ("in Missa Vigiliae paschalis"). *)
  check "RG 23(b)/476(a): Holy Saturday (the Easter Vigil Mass)" 2026 4 4 false

(* ---- RG 476(b) negative: a plain II-class saint, not Domini/BVM, not an
   Apostle/Evangelist ---- *)

let test_476b_plain_class2_saint () =
  (* 2026-08-10: St Lawrence, Class2, subject Saint -- a deacon and martyr,
     no Apostle/Evangelist connection, not on any list this module reads. *)
  check "476(b): a plain II-class saint (Lawrence) does not say the Creed" 2026 8 10 false

(* ---- RG 28-34 (vigils): checked ahead of 475(c) so a Class2 vigil that
   is ALSO on marian_slugs is still excluded ---- *)

let test_vigil_excluded_even_when_class2_and_marian () =
  (* 2026-08-14: Vigil of the Assumption, Class2 -- IS on
     {!Rite_ef.Precedence_ef.marian_slugs} (a real Marian entry), so without
     the vigil check ahead of 475(c) this would wrongly come out [true].
     Also carries a real commemoration (+eusebius-confessor), a second live
     476(e) instance. *)
  check "vigils are excluded even when Class2 and Marian (Vigil of the Assumption)" 2026 8 14 false

(* ---- RG 476(d): a IV-class office (also exercises RG 78/309(a)'s votive
   Office of the BVM on Saturday, itself IV class) ---- *)

let test_476d_bvm_saturday_office () =
  (* 2026-07-11: the unoccupied Saturday's Office of Our Lady, Class4 --
     already a pinned example in test/cli.t (Task 4). *)
  check "476(d): the BVM Saturday Office, IV class" 2026 7 11 false

(* One full civil year, walked day by day: RG 475(a)'s own invariant, "every
   Sunday says the Creed, no exceptions" -- the same sanity check the task
   asks for at the domain-measurement step, pinned here as a real assertion
   rather than left to a one-off shell scan. *)
let test_every_sunday_in_2026_says_the_creed () =
  let days = Cal.year ctx layer 2026 in
  Array.iter
    (fun (d : (V.season, V.rank) LD.t) ->
      if d.LD.temporal.Temporal.weekday = Date.Sun then
        Alcotest.(check bool)
          (Printf.sprintf "%s is a Sunday: creed must be true" (Date.to_iso8601 d.LD.date))
          true d.LD.creed)
    days

let suite =
  ( "Rubrics_ef",
    [ Alcotest.test_case "475(a): ordinary Sunday" `Quick test_475a_ordinary_sunday;
      Alcotest.test_case "475(a): reads [temporal], not [observed] (Trap One)" `Quick
        test_475a_reads_temporal_not_observed;
      Alcotest.test_case "475(b): I-class feast" `Quick test_475b_class1_feast;
      Alcotest.test_case "475(c): II-class feast of the Lord" `Quick test_475c_lord;
      Alcotest.test_case "475(c): II-class BVM feast via marian_slugs" `Quick
        test_475c_bvm_via_marian_slugs;
      Alcotest.test_case "475(d): octave overrides an occurring feast" `Quick
        test_475d_octave_even_occurring_feast;
      Alcotest.test_case "475(d): 1 January octave-day boundary" `Quick test_475d_octave_day_boundary;
      Alcotest.test_case "475(e): an Apostle's own natalicium" `Quick test_475e_apostle_natalicium;
      Alcotest.test_case "475(e): Barnabas, named explicitly" `Quick
        test_475e_barnabas_named_explicitly;
      Alcotest.test_case "475(e): Chair of Peter, named explicitly" `Quick
        test_475e_chair_of_peter_named_explicitly;
      Alcotest.test_case "475(e) excludes the Conversion of St Paul (Trap Two)" `Quick
        test_475e_excludes_conversion_of_paul;
      Alcotest.test_case "RG 23/476: Ash Wednesday" `Quick test_ash_wednesday_no_creed;
      Alcotest.test_case "RG 23/476(a): Holy Thursday" `Quick test_holy_thursday_no_creed;
      Alcotest.test_case "RG 23/476(a): Holy Saturday / Easter Vigil" `Quick
        test_holy_saturday_easter_vigil_no_creed;
      Alcotest.test_case "476(b): plain II-class saint (negative)" `Quick
        test_476b_plain_class2_saint;
      Alcotest.test_case "vigils excluded even when Class2 and Marian" `Quick
        test_vigil_excluded_even_when_class2_and_marian;
      Alcotest.test_case "476(d): BVM Saturday Office, IV class" `Quick test_476d_bvm_saturday_office;
      Alcotest.test_case "every Sunday in 2026 says the Creed" `Quick
        test_every_sunday_in_2026_says_the_creed ] )