%% shnei_ketuvim.pl — Rule 13: Two contradicting verses resolved by a third.
%%
%% Shnei ketuvim hamach'chishim zeh et zeh —
%% Two verses that contradict each other, until a third verse
%% comes and resolves the contradiction.
%%
%% This is the most dialectical of the 13 rules.
%% It is the hermeneutical engine behind machloket:
%% two positions hold, both grounded in Torah, until
%% a third source harmonizes them.
%%
%% If no third verse resolves: teiku.

:- module(shnei_ketuvim, [
    shnei_ketuvim/4,
    verses_contradict/3,
    resolving_verse/3,
    harmonize/4,
    domains_in_tension/2
]).

:- use_module('../specification/torah_text').
:- use_module('../specification/root_meanings').
:- use_module('../specification/relationships').

%% ============================================================
%% CONTRADICTION DETECTION
%% ============================================================

%% verses_contradict(Verse1, Verse2, TensionType)
%% Two verses have opposing implications.

%% Verses contradict if their roots map to conflicting domains
verses_contradict(ref(B1,C1,V1), ref(B2,C2,V2), domain_conflict(D1, D2)) :-
    verse(B1, C1, V1, Roots1, _),
    verse(B2, C2, V2, Roots2, _),
    member(R1, Roots1),
    member(R2, Roots2),
    root_domain(R1, D1),
    root_domain(R2, D2),
    domains_in_tension(D1, D2),
    ref(B1,C1,V1) \= ref(B2,C2,V2).

%% Domains that are in inherent tension
domains_in_tension(judgment, mercy).
domains_in_tension(mercy, judgment).
domains_in_tension(holiness, transgression).
domains_in_tension(transgression, holiness).
domains_in_tension(death, mercy).
domains_in_tension(mercy, death).
domains_in_tension(authority, covenant).
domains_in_tension(covenant, authority).

%% ============================================================
%% RESOLVING VERSE
%% ============================================================

%% resolving_verse(Verse1, Verse2, Verse3)
%% Verse3 resolves the contradiction between Verse1 and Verse2.
%% It does this by sharing roots with BOTH contradicting verses.

resolving_verse(ref(B1,C1,V1), ref(B2,C2,V2), ref(B3,C3,V3)) :-
    verse(B1, C1, V1, Roots1, _),
    verse(B2, C2, V2, Roots2, _),
    verse(B3, C3, V3, Roots3, _),
    %% Third verse shares a root with first verse
    member(SharedRoot1, Roots1),
    member(SharedRoot1, Roots3),
    %% Third verse shares a root with second verse
    member(SharedRoot2, Roots2),
    member(SharedRoot2, Roots3),
    %% Third verse is different from both
    ref(B3,C3,V3) \= ref(B1,C1,V1),
    ref(B3,C3,V3) \= ref(B2,C2,V2).

%% ============================================================
%% HARMONIZATION
%% ============================================================

%% harmonize(Verse1, Verse2, Verse3, Resolution)
%% Produces a harmonized reading using the third verse.

harmonize(V1, V2, V3, Resolution) :-
    verses_contradict(V1, V2, Tension),
    resolving_verse(V1, V2, V3),
    Resolution = harmonized(V1, V2, resolved_by(V3), tension(Tension)).

%% ============================================================
%% SHNEI KETUVIM — UNIFIED INTERFACE
%% ============================================================

%% shnei_ketuvim(Input, Output, Reasoning, ThirdVerse)
shnei_ketuvim(
    contradicting(V1, V2),
    harmonized_reading(V1, V2, V3),
    reasoning(V1, contradicts(V2), resolved_by(V3)),
    V3
) :-
    harmonize(V1, V2, V3, _).

%% When no resolving verse exists: teiku
shnei_ketuvim(
    contradicting(V1, V2),
    teiku(V1, V2),
    reasoning(V1, contradicts(V2), no_resolution_found),
    none
) :-
    verses_contradict(V1, V2, _),
    \+ resolving_verse(V1, V2, _).