import {
  buildAssistantMcpDiscoveryAnswerDraft,
  type AssistantMcpDiscoveryAnswerDraftContract
} from "./assistantMcpDiscoveryAnswerAdapter";
import {
  executeAssistantMcpDiscoveryPilot,
  type AssistantMcpDiscoveryPilotExecutionContract,
  type AssistantMcpDiscoveryPilotExecutorDeps
} from "./assistantMcpDiscoveryPilotExecutor";
import {
  planAssistantMcpDiscovery,
  type AssistantMcpDiscoveryChainId,
  type AssistantMcpDiscoveryMetadataSurfaceRef,
  type AssistantMcpDiscoveryPlannerContract
} from "./assistantMcpDiscoveryPlanner";
import type { AssistantMcpDiscoveryDataNeedGraphContract } from "./assistantMcpDiscoveryDataNeedGraph";
import type { AssistantMcpDiscoveryTurnMeaningRef } from "./assistantMcpDiscoveryPolicy";

export const ASSISTANT_MCP_DISCOVERY_RUNTIME_BRIDGE_SCHEMA_VERSION =
  "assistant_mcp_discovery_runtime_bridge_v1" as const;
export const ASSISTANT_MCP_DISCOVERY_LOOP_STATE_SCHEMA_VERSION =
  "assistant_mcp_discovery_loop_state_v1" as const;

export type AssistantMcpDiscoveryRuntimeBridgeStatus =
  | "answer_draft_ready"
  | "checked_sources_only"
  | "needs_clarification"
  | "blocked"
  | "unsupported";
export type AssistantMcpDiscoveryLoopStatus =
  | "awaiting_clarification"
  | "ready_for_next_hop"
  | "blocked";

export interface AssistantMcpDiscoveryRuntimeBridgeInput {
  semanticDataNeed?: string | null;
  dataNeedGraph?: AssistantMcpDiscoveryDataNeedGraphContract | null;
  metadataSurface?: AssistantMcpDiscoveryMetadataSurfaceRef | null;
  turnMeaning?: AssistantMcpDiscoveryTurnMeaningRef | null;
  deps?: AssistantMcpDiscoveryPilotExecutorDeps;
}

export interface AssistantMcpDiscoveryLoopStateContract {
  schema_version: typeof ASSISTANT_MCP_DISCOVERY_LOOP_STATE_SCHEMA_VERSION;
  policy_owner: "assistantMcpDiscoveryRuntimeBridge";
  loop_status: AssistantMcpDiscoveryLoopStatus;
  selected_chain_id: AssistantMcpDiscoveryChainId;
  pilot_scope: AssistantMcpDiscoveryPilotExecutionContract["pilot_scope"];
  asked_domain_family: string | null;
  asked_action_family: string | null;
  unsupported_but_understood_family: string | null;
  ranking_need: string | null;
  pending_axes: string[];
  provided_axes: string[];
  explicit_entity_candidates: string[];
  metadata_scope_hint: string | null;
  subject_resolution_optional: boolean;
  explicit_organization_scope: string | null;
  explicit_date_scope: string | null;
}

export interface AssistantMcpDiscoveryRuntimeBridgeContract {
  schema_version: typeof ASSISTANT_MCP_DISCOVERY_RUNTIME_BRIDGE_SCHEMA_VERSION;
  policy_owner: "assistantMcpDiscoveryRuntimeBridge";
  bridge_status: AssistantMcpDiscoveryRuntimeBridgeStatus;
  hot_runtime_wired: false;
  planner: AssistantMcpDiscoveryPlannerContract;
  pilot: AssistantMcpDiscoveryPilotExecutionContract;
  answer_draft: AssistantMcpDiscoveryAnswerDraftContract;
  loop_state: AssistantMcpDiscoveryLoopStateContract;
  user_facing_response_allowed: boolean;
  business_fact_answer_allowed: boolean;
  requires_user_clarification: boolean;
  reason_codes: string[];
}

function normalizeReasonCode(value: string): string | null {
  const normalized = value
    .trim()
    .replace(/[^\p{L}\p{N}_.:-]+/gu, "_")
    .replace(/^_+|_+$/g, "")
    .toLowerCase();
  return normalized.length > 0 ? normalized.slice(0, 120) : null;
}

function pushReason(target: string[], value: string): void {
  const normalized = normalizeReasonCode(value);
  if (normalized && !target.includes(normalized)) {
    target.push(normalized);
  }
}

function uniqueStrings(values: string[]): string[] {
  const result: string[] = [];
  for (const value of values) {
    const text = String(value ?? "").trim();
    if (text && !result.includes(text)) {
      result.push(text);
    }
  }
  return result;
}

function bridgeStatusFor(
  pilot: AssistantMcpDiscoveryPilotExecutionContract,
  draft: AssistantMcpDiscoveryAnswerDraftContract
): AssistantMcpDiscoveryRuntimeBridgeStatus {
  if (draft.answer_mode === "blocked" || pilot.pilot_status === "blocked") {
    return "blocked";
  }
  if (draft.answer_mode === "needs_clarification" || pilot.pilot_status === "skipped_needs_clarification") {
    return "needs_clarification";
  }
  if (pilot.pilot_status === "unsupported") {
    return "unsupported";
  }
  if (draft.answer_mode === "checked_sources_only") {
    return "checked_sources_only";
  }
  return "answer_draft_ready";
}

function businessFactAnswerAllowed(draft: AssistantMcpDiscoveryAnswerDraftContract): boolean {
  return draft.answer_mode === "confirmed_with_bounded_inference" || draft.answer_mode === "bounded_inference_only";
}

function loopStatusFor(
  bridgeStatus: AssistantMcpDiscoveryRuntimeBridgeStatus
): AssistantMcpDiscoveryLoopStatus {
  if (bridgeStatus === "needs_clarification") {
    return "awaiting_clarification";
  }
  if (bridgeStatus === "blocked" || bridgeStatus === "unsupported") {
    return "blocked";
  }
  return "ready_for_next_hop";
}

function flattenAxes(
  pilot: AssistantMcpDiscoveryPilotExecutionContract,
  source: "provided_axes" | "missing_axis_options"
): string[] {
  const result: string[] = [];
  for (const step of pilot.dry_run.execution_steps) {
    if (source === "provided_axes") {
      for (const axis of step.provided_axes) {
        if (axis && !result.includes(axis)) {
          result.push(axis);
        }
      }
      continue;
    }
    for (const option of step.missing_axis_options) {
      for (const axis of option) {
        if (axis && !result.includes(axis)) {
          result.push(axis);
        }
      }
    }
  }
  return result;
}

function entityCandidatesFromPlanner(planner: AssistantMcpDiscoveryPlannerContract): string[] {
  const values = planner.discovery_plan.turn_meaning_ref?.explicit_entity_candidates ?? [];
  return uniqueStrings(values);
}

function buildLoopState(
  planner: AssistantMcpDiscoveryPlannerContract,
  pilot: AssistantMcpDiscoveryPilotExecutionContract,
  bridgeStatus: AssistantMcpDiscoveryRuntimeBridgeStatus
): AssistantMcpDiscoveryLoopStateContract {
  const plannerClarificationGaps = planner.discovery_plan.clarification_gaps ?? [];
  return {
    schema_version: ASSISTANT_MCP_DISCOVERY_LOOP_STATE_SCHEMA_VERSION,
    policy_owner: "assistantMcpDiscoveryRuntimeBridge",
    loop_status: loopStatusFor(bridgeStatus),
    selected_chain_id: planner.selected_chain_id,
    pilot_scope: pilot.pilot_scope,
    asked_domain_family: planner.discovery_plan.turn_meaning_ref?.asked_domain_family ?? null,
    asked_action_family: planner.discovery_plan.turn_meaning_ref?.asked_action_family ?? null,
    unsupported_but_understood_family:
      planner.discovery_plan.turn_meaning_ref?.unsupported_but_understood_family ?? null,
    ranking_need: planner.data_need_graph?.ranking_need ?? planner.discovery_plan.turn_meaning_ref?.seeded_ranking_need ?? null,
    pending_axes: plannerClarificationGaps.length > 0 ? plannerClarificationGaps : flattenAxes(pilot, "missing_axis_options"),
    provided_axes: flattenAxes(pilot, "provided_axes"),
    explicit_entity_candidates: entityCandidatesFromPlanner(planner),
    metadata_scope_hint:
      planner.discovery_plan.turn_meaning_ref?.metadata_scope_hint ??
      planner.data_need_graph?.metadata_scope_hint ??
      null,
    subject_resolution_optional:
      planner.discovery_plan.turn_meaning_ref?.subject_resolution_optional === true ||
      planner.data_need_graph?.subject_resolution_optional === true,
    explicit_organization_scope: planner.discovery_plan.turn_meaning_ref?.explicit_organization_scope ?? null,
    explicit_date_scope: planner.discovery_plan.turn_meaning_ref?.explicit_date_scope ?? null
  };
}

export async function runAssistantMcpDiscoveryRuntimeBridge(
  input: AssistantMcpDiscoveryRuntimeBridgeInput
): Promise<AssistantMcpDiscoveryRuntimeBridgeContract> {
  const planner = planAssistantMcpDiscovery({
    semanticDataNeed: input.semanticDataNeed,
    dataNeedGraph: input.dataNeedGraph,
    metadataSurface: input.metadataSurface,
    turnMeaning: input.turnMeaning
  });
  const pilot = await executeAssistantMcpDiscoveryPilot(planner, input.deps);
  const answerDraft = buildAssistantMcpDiscoveryAnswerDraft(pilot);
  const bridgeStatus = bridgeStatusFor(pilot, answerDraft);
  const loopState = buildLoopState(planner, pilot, bridgeStatus);
  const reasonCodes = uniqueStrings([...planner.reason_codes, ...pilot.reason_codes, ...answerDraft.reason_codes]);

  pushReason(reasonCodes, `runtime_bridge_status_${bridgeStatus}`);
  pushReason(reasonCodes, "runtime_bridge_not_wired_to_hot_assistant_answer");
  pushReason(reasonCodes, `runtime_bridge_loop_state_${loopState.loop_status}`);

  return {
    schema_version: ASSISTANT_MCP_DISCOVERY_RUNTIME_BRIDGE_SCHEMA_VERSION,
    policy_owner: "assistantMcpDiscoveryRuntimeBridge",
    bridge_status: bridgeStatus,
    hot_runtime_wired: false,
    planner,
    pilot,
    answer_draft: answerDraft,
    loop_state: loopState,
    user_facing_response_allowed: bridgeStatus !== "blocked",
    business_fact_answer_allowed: businessFactAnswerAllowed(answerDraft),
    requires_user_clarification: bridgeStatus === "needs_clarification",
    reason_codes: reasonCodes
  };
}