// The IDEOLOGY ability (v0.39, #62) as a modular LLM-ability (v0.40.0, #67).
// The model may change a nation's form of government (its `ideology` field) —
// a free-form label such as "democracy", "fascism", or "military junta" — via
// a coup, revolution, reform, or constitutional change. On a valid change the
// target's `ideology` is set, a DETERMINISTIC stability dip
// (`IDEOLOGY_STABILITY_EFFECT`, −5) is applied to its `stats.stability`
// (clamped) and mirrored to every region the nation owns (`regionStats`), the
// nation's derived stats are re-derived afterwards (the same 0-region /
// no-entry guards), and a narration event is appended. The change never moves
// territory (sole ownership is untouched). All bodies are moved VERBATIM from
// the pre-refactor engine.ts.

import { deriveNationStats, makeEvent } from '../../shared/protocol';
import { clampStat, IDEOLOGY_STABILITY_EFFECT } from '../../shared/protocol';
import type { GameState } from '../../shared/types';
import type { IdeologyChange } from '../../shared/protocol';
import { resolveNationRef, str } from './shared';
import type { Ability } from './types';

/**
 * (v0.39, #62) Validate the raw `ideology` object of a turn into a safe
 * `IdeologyChange[]`. Defensive like the rest of the parser — never throws.
 * Accepts a `{ changes: [...] }` object or a bare array (lenient). Each
 * change needs a non-empty `target` (a nation ref, capped at 120 chars) and
 * a non-empty, non-whitespace `to` (the new form of government, capped at
 * 120 chars). Refs stay raw here (resolved against the real state at apply
 * time, like the wars / hybrid / nuclear / leader ops); an unresolvable
 * target is dropped at apply time, never thrown.
 */
export function validateIdeologyOps(raw: unknown): IdeologyChange[] {
  const out: IdeologyChange[] = [];
  const list = Array.isArray(raw)
    ? raw
    : raw && typeof raw === 'object'
      ? (raw as Record<string, unknown>).changes
      : undefined;
  if (!Array.isArray(list)) return out;
  for (const e of list) {
    if (!e || typeof e !== 'object') continue;
    const s = e as Record<string, unknown>;
    const target = str(s.target, 120);
    const to = str(s.to, 120);
    if (!target || !to) continue;
    out.push({ target, to });
  }
  return out;
}

/**
 * (v0.39, #62) Apply a single ideology change to `next` (in place). The
 * target nation is resolved by the shared resolver (id first, then a
 * case-insensitive unique name; an unknown or ambiguous ref is dropped,
 * never thrown). On a valid change the target's `ideology` is set to the new
 * government type (re-setting the same value is idempotent for the field but
 * still narrated) and a DETERMINISTIC stability dip
 * (`IDEOLOGY_STABILITY_EFFECT`, −5) is applied to its `stats.stability`
 * (clamped 0–100) and mirrored to every region the nation owns
 * (`regionStats`); the nation's derived stats are re-derived afterwards (the
 * same 0-region / no-entry guards as the hybrid/economy/industry/leader
 * effects, so a 0-region nation keeps its directly-mutated value). Finally a
 * narration event is appended: a `political` event for the government shift.
 * The change never moves territory (sole ownership is untouched).
 */
function applyIdeologyChange(
  next: GameState,
  op: IdeologyChange,
  geoOf?: (key: string) => { area: number; population: number } | undefined,
  actingTurn?: number,
): void {
  const turn = actingTurn ?? next.turn;
  const id = resolveNationRef(next, op.target);
  if (id === null) return; // unknown / ambiguous target: drop, never throw
  const n = next.nations[id];

  n.ideology = op.to;

  const delta = IDEOLOGY_STABILITY_EFFECT;
  if (delta !== 0) {
    n.stats.stability = clampStat(n.stats.stability + delta);
    for (const key of n.territory) {
      const rs = next.regionStats[key];
      if (!rs) continue;
      rs.stability = clampStat(rs.stability + delta);
    }
    // Re-derive the nation's aggregate stats (the main recompute ran earlier
    // this turn, so without this the dip would be washed out next turn).
    if (n.territory.length > 0 && n.territory.some((k) => next.regionStats[k])) {
      n.stats = deriveNationStats(n.territory, next.regionStats, geoOf);
    }
  }

  next.events.push(
    makeEvent(
      {
        nation: n.id,
        type: 'political',
        title: `${n.name}'s government shifted to ${op.to}`,
        text: `${n.name} has changed its form of government to ${op.to}.`,
        outcome: 'success',
      },
      turn,
      next.date,
    ),
  );
}

export const ideology: Ability<'ideology'> = {
  field: 'ideology',
  default: () => ({ changes: [] }),
  // The low-level validator returns a bare list; the field's shape is the
  // `{ changes }` object (mirrors the historical `result.ideology = { changes: ... }`).
  validate: (raw) => ({ changes: validateIdeologyOps(raw) }),
  apply: (state, data, ctx) => {
    for (const ch of data.changes) applyIdeologyChange(state, ch, ctx.geoOf, ctx.actingTurn);
  },
  schemaLine: () =>
    '  "ideology": {"changes":[{"target":"<nation id or name>","to":"<new form of government>"}]},',
  constraint: () =>
    '- Ideology ("ideology") is each nation\'s form of government — a free-form label such as "democracy", "fascism", or "military junta" — that can shift through a coup, a revolution, a reform, or a constitutional change. Each change is {"target":"<nation id or name>","to":"<new form of government>"}: the engine sets the nation\'s ideology, applies a small, deterministic stability dip (−5 — a regime shift always unsettles a nation), and narrates it with a "political" event. It is a third axis, distinct from a takeover (which RENAMES the nation) and from a leader change (who is in charge): the nation keeps its id, name, territory, relations, and leader — only its form of government and its stability move. Similar forms of government are a SOFT, prompt-level compatibility nudge only (nations with alike ideologies tend to ally and trade; very opposed ones tend to clash) — there is no engine gate behind it. Propose at most 1-2 changes per turn and narrate each one in "events". The user message\'s "nations" field lists each nation\'s current "ideology" (omitted when a nation has none).',
  isMeaningful: (data) => data.changes.length > 0,
  stub: () => ({ changes: [] }),
  payload: () => ({}),
};