import type { AssistantMcpDiscoveryDataNeedGraphContract } from "./assistantMcpDiscoveryDataNeedGraph";
import type {
  AssistantMcpDiscoveryPlanContract,
  AssistantMcpDiscoveryPrimitive,
  AssistantMcpDiscoveryTurnMeaningRef
} from "./assistantMcpDiscoveryPolicy";

export const ASSISTANT_EVIDENCE_PLANNER_SCHEMA_VERSION = "assistant_evidence_planner_v1" as const;

export type AssistantEvidencePlannerStatus = "ready_for_execution" | "needs_clarification" | "blocked";
export type AssistantEvidenceCoverageExpectation = "confirmed_coverage" | "bounded_inference" | "clarification";
export type AssistantEvidenceAnswerMode =
  | "confirmed_business_answer"
  | "bounded_business_inference"
  | "clarification_required"
  | "checked_sources_only";

export interface AssistantEvidenceDataNeedContract {
  business_fact_family: string | null;
  action_family: string | null;
  aggregation_need: string | null;
  comparison_need: string | null;
  ranking_need: string | null;
  time_scope_need: string | null;
  proof_expectation: string | null;
  subject_candidates: string[];
}

export interface AssistantEvidenceAxesContract {
  required_axes: string[];
  provided_axes: string[];
  missing_axes: string[];
  user_actionable_missing_axes: string[];
  clarification_gaps: string[];
}

export interface AssistantEvidencePrimitivePlanContract {
  selected_chain_id: string;
  allowed_primitives: AssistantMcpDiscoveryPrimitive[];
  rejected_primitives: string[];
  execution_budget: AssistantMcpDiscoveryPlanContract["execution_budget"];
}

export interface AssistantEvidenceCoverageGateContract {
  requires_evidence_gate: true;
  expected_coverage: AssistantEvidenceCoverageExpectation;
  answer_permission_if_satisfied: AssistantEvidenceAnswerMode;
  answer_may_use_raw_model_claims: false;
}

export interface AssistantEvidenceAnswerContract {
  answer_mode: AssistantEvidenceAnswerMode;
  required_user_layers: string[];
  forbidden_overclaim_flags: string[];
  must_keep_internal_mechanics_hidden: true;
}

export interface AssistantEvidencePlannerContract {
  schema_version: typeof ASSISTANT_EVIDENCE_PLANNER_SCHEMA_VERSION;
  policy_owner: "assistantEvidencePlanner";
  planner_status: AssistantEvidencePlannerStatus;
  semantic_data_need: string | null;
  selected_chain_id: string;
  data_need: AssistantEvidenceDataNeedContract;
  evidence_axes: AssistantEvidenceAxesContract;
  primitive_plan: AssistantEvidencePrimitivePlanContract;
  coverage_gate: AssistantEvidenceCoverageGateContract;
  answer_contract: AssistantEvidenceAnswerContract;
  reason_codes: string[];
}

export interface BuildAssistantEvidencePlannerInput {
  selectedChainId: string;
  plannerStatus: AssistantEvidencePlannerStatus;
  semanticDataNeed?: string | null;
  dataNeedGraph?: AssistantMcpDiscoveryDataNeedGraphContract | null;
  discoveryPlan: AssistantMcpDiscoveryPlanContract;
  additionalMissingAxes?: string[] | null;
}

function toNonEmptyString(value: unknown): string | null {
  if (value === null || value === undefined) {
    return null;
  }
  const text = String(value).trim();
  return text.length > 0 ? text : null;
}

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: unknown[]): string[] {
  const result: string[] = [];
  for (const value of values) {
    const text = toNonEmptyString(value);
    if (text && !result.includes(text)) {
      result.push(text);
    }
  }
  return result;
}

function providedAxesFromMeaning(meaning: AssistantMcpDiscoveryTurnMeaningRef | null): string[] {
  const result: string[] = [];
  if ((meaning?.explicit_entity_candidates?.length ?? 0) > 0) {
    result.push("counterparty");
    result.push("business_entity");
  }
  if (toNonEmptyString(meaning?.explicit_organization_scope)) {
    result.push("organization");
  }
  if (toNonEmptyString(meaning?.explicit_date_scope)) {
    result.push("period");
  }
  if (toNonEmptyString(meaning?.asked_aggregation_axis)) {
    result.push("aggregate_axis");
  }
  if (toNonEmptyString(meaning?.metadata_scope_hint)) {
    result.push("metadata_scope");
  }
  return uniqueStrings(result);
}

function missingAxes(requiredAxes: string[], providedAxes: string[]): string[] {
  return requiredAxes.filter((axis) => !providedAxes.includes(axis));
}

const USER_ACTIONABLE_AXIS_SET = new Set([
  "counterparty",
  "business_entity",
  "organization",
  "period",
  "as_of_date",
  "item",
  "supplier",
  "buyer",
  "warehouse",
  "document",
  "contract",
  "metadata_scope",
  "lane_family_choice"
]);

function userActionableMissingAxes(axes: string[]): string[] {
  return axes.filter((axis) => USER_ACTIONABLE_AXIS_SET.has(axis));
}

function coverageExpectationFor(
  graph: AssistantMcpDiscoveryDataNeedGraphContract | null
): AssistantEvidenceCoverageExpectation {
  if (graph?.proof_expectation === "bounded_inference") {
    return "bounded_inference";
  }
  if (graph?.proof_expectation === "clarification_required") {
    return "clarification";
  }
  return "confirmed_coverage";
}

function answerModeFor(input: {
  plannerStatus: AssistantEvidencePlannerStatus;
  coverageExpectation: AssistantEvidenceCoverageExpectation;
}): AssistantEvidenceAnswerMode {
  if (input.plannerStatus === "needs_clarification") {
    return "clarification_required";
  }
  if (input.plannerStatus === "blocked") {
    return "checked_sources_only";
  }
  if (input.coverageExpectation === "bounded_inference") {
    return "bounded_business_inference";
  }
  if (input.coverageExpectation === "clarification") {
    return "clarification_required";
  }
  return "confirmed_business_answer";
}

function requiredUserLayersFor(answerMode: AssistantEvidenceAnswerMode): string[] {
  if (answerMode === "clarification_required") {
    return ["clarifying_question", "why_needed", "available_calculation"];
  }
  if (answerMode === "bounded_business_inference") {
    return ["business_conclusion", "key_figures", "evidence_boundary", "next_step"];
  }
  if (answerMode === "checked_sources_only") {
    return ["checked_sources_boundary", "unknowns", "next_probe"];
  }
  return ["direct_business_answer", "key_figures", "evidence_boundary", "next_step"];
}

export function buildAssistantEvidencePlanner(
  input: BuildAssistantEvidencePlannerInput
): AssistantEvidencePlannerContract {
  const graph = input.dataNeedGraph ?? null;
  const plan = input.discoveryPlan;
  const turnMeaning = plan.turn_meaning_ref;
  const requiredAxes = uniqueStrings(plan.required_axes);
  const providedAxes = providedAxesFromMeaning(turnMeaning);
  const graphClarificationGaps = uniqueStrings(graph?.clarification_gaps ?? []);
  const additionalAxisGaps = uniqueStrings(input.additionalMissingAxes ?? []).filter(
    (axis) => !providedAxes.includes(axis) && (requiredAxes.includes(axis) || USER_ACTIONABLE_AXIS_SET.has(axis)),
  );
  const axisGaps = uniqueStrings([...additionalAxisGaps, ...missingAxes(requiredAxes, providedAxes)]);
  const actionableAxisGaps = userActionableMissingAxes(axisGaps);
  const clarificationGaps = uniqueStrings([...graphClarificationGaps, ...axisGaps]);
  const coverageExpectation = coverageExpectationFor(graph);
  const answerMode = answerModeFor({
    plannerStatus: input.plannerStatus,
    coverageExpectation
  });
  const reasonCodes = uniqueStrings(plan.reason_codes);

  pushReason(reasonCodes, "evidence_planner_contract_built");
  if (graph) {
    pushReason(reasonCodes, "evidence_planner_consumed_data_need_graph");
  }
  if (clarificationGaps.length > 0) {
    pushReason(reasonCodes, "evidence_planner_has_missing_axes_or_gaps");
  }

  return {
    schema_version: ASSISTANT_EVIDENCE_PLANNER_SCHEMA_VERSION,
    policy_owner: "assistantEvidencePlanner",
    planner_status: input.plannerStatus,
    semantic_data_need: toNonEmptyString(input.semanticDataNeed),
    selected_chain_id: input.selectedChainId,
    data_need: {
      business_fact_family: graph?.business_fact_family ?? null,
      action_family: graph?.action_family ?? null,
      aggregation_need: graph?.aggregation_need ?? null,
      comparison_need: graph?.comparison_need ?? null,
      ranking_need: graph?.ranking_need ?? null,
      time_scope_need: graph?.time_scope_need ?? null,
      proof_expectation: graph?.proof_expectation ?? null,
      subject_candidates: uniqueStrings(graph?.subject_candidates ?? [])
    },
    evidence_axes: {
      required_axes: requiredAxes,
      provided_axes: providedAxes,
      missing_axes: axisGaps,
      user_actionable_missing_axes: actionableAxisGaps,
      clarification_gaps: clarificationGaps
    },
    primitive_plan: {
      selected_chain_id: input.selectedChainId,
      allowed_primitives: plan.allowed_primitives,
      rejected_primitives: plan.rejected_primitives,
      execution_budget: plan.execution_budget
    },
    coverage_gate: {
      requires_evidence_gate: true,
      expected_coverage: coverageExpectation,
      answer_permission_if_satisfied: answerMode,
      answer_may_use_raw_model_claims: false
    },
    answer_contract: {
      answer_mode: answerMode,
      required_user_layers: requiredUserLayersFor(answerMode),
      forbidden_overclaim_flags: uniqueStrings(graph?.forbidden_overclaim_flags ?? []),
      must_keep_internal_mechanics_hidden: true
    },
    reason_codes: reasonCodes
  };
}