/** Fail-closed suggestion.schema.json adapters for HUX-09. */

import {
  asRecord,
  exactKeys,
  isId,
  isSafeText,
  isUtc,
  normalizeIdentity,
  normalizeTrigger,
  sameIdentity,
  sameTrigger,
} from "./security.ts";
import type {
  OnboardingActionIntent,
  OnboardingScope,
  OnboardingSuggestion,
  RawSuggestion,
  RawSuggestionState,
  ScopedIdentity,
  SuggestionActionType,
  SuggestionDecision,
  SuggestionEvaluation,
  SuggestionKind,
  SuggestionState,
} from "./types.ts";

export const FOUNDATION_FLAG = "hux.foundation";
export const PROJECTS_FLAG = "hux.projects";
export const FRIENDLY_MODES_FLAG = "hux.friendly_modes";
export const ONBOARDING_FLAG = "hux.onboarding";
export const PRIVACY_FLAG = "hux.privacy";
export const REQUIRED_FLAGS = Object.freeze([
  FOUNDATION_FLAG,
  PROJECTS_FLAG,
  FRIENDLY_MODES_FLAG,
  ONBOARDING_FLAG,
]);

const KINDS = new Set<SuggestionKind>(["workflow", "project", "feature", "tip"]);
const ACTIONS = new Set<SuggestionActionType>([
  "open_mode", "create_project", "open_memory", "open_artifacts",
  "start_workflow", "none",
]);
const MODES = new Set(["fast", "thoughtful", "research", "create", "private"]);
const INTENTS = new Set(["schedule_weekly", "save_reusable"]);
const KIND_ACTIONS: Readonly<Record<SuggestionKind, ReadonlySet<SuggestionActionType>>> = {
  workflow: new Set(["start_workflow"]),
  project: new Set(["create_project"]),
  feature: new Set(["open_mode", "open_memory", "open_artifacts"]),
  tip: new Set(["none"]),
};

function finiteInteger(value: unknown, min: number, max: number): value is number {
  return Number.isSafeInteger(value) && (value as number) >= min && (value as number) <= max;
}

function normalizePayload(
  type: SuggestionActionType,
  raw: unknown,
): Readonly<Record<string, string>> | null | undefined {
  const value = raw === undefined ? {} : asRecord(raw);
  if (!value) return null;
  if (type === "start_workflow") {
    return exactKeys(value, ["intent"]) && INTENTS.has(value.intent as string) ?
      {intent: value.intent as string} : null;
  }
  if (type === "create_project") {
    if (!exactKeys(value, [], ["prefill_title"])) return null;
    return value.prefill_title === undefined ? {} :
      isSafeText(value.prefill_title, 1, 120) ? {prefill_title: value.prefill_title} : null;
  }
  if (type === "open_mode") {
    if (!exactKeys(value, [], ["mode"])) return null;
    return value.mode === undefined ? {} : MODES.has(value.mode as string) ?
      {mode: value.mode as string} : null;
  }
  if (type === "open_memory") {
    return exactKeys(value, [], ["view"]) &&
      (value.view === undefined || value.view === "suggestions") ?
      (value.view ? {view: "suggestions"} : {}) : null;
  }
  if (type === "open_artifacts") {
    return exactKeys(value, [], ["view"]) &&
      (value.view === undefined || value.view === "current") ?
      (value.view ? {view: "current"} : {}) : null;
  }
  return exactKeys(value, []) ? undefined : null;
}

export function onboardingEnabled(flags?: Iterable<string>): boolean {
  if (!flags) return false;
  const enabled = new Set(flags);
  return REQUIRED_FLAGS.every((flag) => enabled.has(flag));
}

export function normalizeSuggestion(
  raw: RawSuggestion,
  expectedTrigger: OnboardingScope["trigger"],
): OnboardingSuggestion | null {
  const value = asRecord(raw);
  if (!value || !exactKeys(value, [
    "schema", "id", "kind", "trigger", "title", "body", "priority", "suppression",
  ], ["action"]) || value.schema !== "hux.suggestion.v1" || !isId(value.id, "sug") ||
      !KINDS.has(value.kind as SuggestionKind) || !isSafeText(value.title, 1, 80) ||
      !isSafeText(value.body, 1, 280) || !finiteInteger(value.priority, 0, 100)) return null;
  const trigger = normalizeTrigger(value.trigger);
  const suppression = asRecord(value.suppression);
  if (!trigger || !sameTrigger(trigger, expectedTrigger) || !suppression ||
      !exactKeys(suppression, [
        "dismissable", "max_shows", "cooldown_seconds", "never_again_supported",
      ]) || suppression.dismissable !== true || suppression.never_again_supported !== true ||
      !finiteInteger(suppression.max_shows, 1, 5) ||
      !finiteInteger(suppression.cooldown_seconds, 3600, Number.MAX_SAFE_INTEGER)) return null;

  const action = value.action === undefined ? {type: "none"} : asRecord(value.action);
  if (!action || !exactKeys(action, ["type"], ["payload"]) ||
      !ACTIONS.has(action.type as SuggestionActionType)) return null;
  const type = action.type as SuggestionActionType;
  const payload = normalizePayload(type, action.payload);
  const kind = value.kind as SuggestionKind;
  if (payload === null || !KIND_ACTIONS[kind].has(type)) return null;
  return {
    schema: "hux.suggestion.v1", id: value.id as string, kind, trigger,
    title: value.title as string, body: value.body as string,
    action: {type, ...(payload === undefined ? {} : {payload})},
    priority: value.priority as number,
    suppression: {
      dismissable: true, maxShows: suppression.max_shows as number,
      cooldownSeconds: suppression.cooldown_seconds as number,
      neverAgainSupported: true,
    },
  };
}

export function normalizeState(
  raw: RawSuggestionState,
  suggestion: OnboardingSuggestion,
  owner: string,
): SuggestionState | null {
  const value = asRecord(raw);
  if (!value || !exactKeys(value, [
    "schema", "owner", "suggestion_id", "shows", "last_shown_at", "never_again",
  ], ["dismissed_at", "acted_at"]) || value.schema !== "hux.suggestion_state.v1" ||
      value.owner !== owner || value.suggestion_id !== suggestion.id ||
      !finiteInteger(value.shows, 1, suggestion.suppression.maxShows) ||
      !isUtc(value.last_shown_at) || value.never_again !== false ||
      (value.dismissed_at !== undefined && !isUtc(value.dismissed_at)) ||
      (value.acted_at !== undefined && !isUtc(value.acted_at))) return null;
  return {
    schema: "hux.suggestion_state.v1", owner, suggestionId: suggestion.id,
    shows: value.shows as number, lastShownAt: value.last_shown_at as string,
    ...(value.dismissed_at ? {dismissedAt: value.dismissed_at as string} : {}),
    ...(value.acted_at ? {actedAt: value.acted_at as string} : {}),
    neverAgain: false,
  };
}

export function normalizeDecisionState(
  raw: RawSuggestionState,
  evaluation: SuggestionEvaluation,
  decision: SuggestionDecision,
): SuggestionState | null {
  const value = asRecord(raw);
  const suggestion = evaluation.suggestion;
  if (!value || !exactKeys(value, [
    "schema", "owner", "suggestion_id", "shows", "last_shown_at", "never_again",
  ], ["dismissed_at", "acted_at"]) || value.schema !== "hux.suggestion_state.v1" ||
      value.owner !== evaluation.identity.userRef || value.suggestion_id !== suggestion.id ||
      value.shows !== evaluation.state.shows || !isUtc(value.last_shown_at) ||
      value.last_shown_at !== evaluation.state.lastShownAt ||
      typeof value.never_again !== "boolean") return null;
  const dismissed = value.dismissed_at === undefined || isUtc(value.dismissed_at);
  const acted = value.acted_at === undefined || isUtc(value.acted_at);
  const outcomeMatches = decision === "acted" ?
    Boolean(value.acted_at) && value.never_again === false :
    Boolean(value.dismissed_at) &&
      value.never_again === (decision === "never_again");
  if (!dismissed || !acted || !outcomeMatches) return null;
  return {
    schema: "hux.suggestion_state.v1", owner: evaluation.identity.userRef,
    suggestionId: suggestion.id, shows: value.shows as number,
    lastShownAt: value.last_shown_at as string,
    ...(value.dismissed_at ? {dismissedAt: value.dismissed_at as string} : {}),
    ...(value.acted_at ? {actedAt: value.acted_at as string} : {}),
    neverAgain: value.never_again,
  };
}

export function normalizeEvaluation(
  raw: unknown,
  expectedIdentity: ScopedIdentity,
  expectedScope: OnboardingScope,
  privacyCapability: boolean,
): SuggestionEvaluation | null {
  const value = asRecord(raw);
  if (!value || !exactKeys(value, [
    "schema", "api_version", "identity", "session_id", "conversation_id", "trigger",
    "privacy", "claim_id", "issued_at", "suggestion", "state",
  ]) || value.schema !== "hux.suggestion_evaluation.v1" || value.api_version !== "hux.v1")
    return null;
  const identity = normalizeIdentity(value.identity);
  const trigger = normalizeTrigger(value.trigger);
  const privacy = asRecord(value.privacy);
  if (!identity || !sameIdentity(identity, expectedIdentity) ||
      value.session_id !== expectedScope.sessionId ||
      value.conversation_id !== expectedScope.conversationId || !trigger ||
      !sameTrigger(trigger, expectedScope.trigger) || !privacy ||
      !exactKeys(privacy, ["schema", "no_store", "memory_suggestions_allowed"]) ||
      privacy.schema !== "hux.onboarding_privacy.v1" ||
      typeof privacy.no_store !== "boolean" ||
      typeof privacy.memory_suggestions_allowed !== "boolean") return null;
  if (privacy.no_store || value.suggestion === null || value.state === null ||
      value.claim_id === null) return null;
  if (!isId(value.claim_id, "clm") || !isUtc(value.issued_at)) return null;
  const suggestion = normalizeSuggestion(value.suggestion as RawSuggestion, expectedScope.trigger);
  if (!suggestion || (suggestion.action.type === "open_memory" &&
      (!privacyCapability || privacy.memory_suggestions_allowed !== true))) return null;
  const state = normalizeState(value.state as RawSuggestionState, suggestion, identity.userRef);
  if (!state) return null;
  return {
    schema: "hux.suggestion_evaluation.v1", identity,
    scope: expectedScope, claimId: value.claim_id, issuedAt: value.issued_at,
    privacy: {
      schema: "hux.onboarding_privacy.v1", noStore: false,
      memorySuggestionsAllowed: privacy.memory_suggestions_allowed,
    },
    suggestion, state,
  };
}

export function buildActionIntent(
  evaluation: SuggestionEvaluation,
): OnboardingActionIntent | null {
  const {action} = evaluation.suggestion;
  const payload = action.payload || {};
  if (action.type === "open_mode") return {type: action.type, ...(payload.mode ? {mode: payload.mode} : {})};
  if (action.type === "create_project") return {type: action.type,
    conversationId: evaluation.scope.conversationId,
    ...(payload.prefill_title ? {prefillTitle: payload.prefill_title} : {})};
  if (action.type === "open_memory") return {type: action.type, view: "suggestions"};
  if (action.type === "open_artifacts") return {type: action.type, view: "current"};
  if (action.type === "start_workflow") return {type: action.type,
    intent: payload.intent as "schedule_weekly" | "save_reusable"};
  return null;
}