import { describe, expect, it } from "vitest";
import { composeAssistantAnswer } from "../src/services/answerComposer";
import type { AnswerGroundingCheck, RequirementCoverageReport, UnifiedRetrievalResult } from "../src/types/assistant";
import type { ProblemUnit, ProblemUnitSummary } from "../src/types/stage2ProblemUnits";

function buildRouteSummary() {
  return {
    mode: "deterministic_v2" as const,
    message_in_scope: true,
    scope_confidence: "high" as const,
    planner: {
      total_fragments: 1,
      in_scope_fragments: 1,
      out_of_scope_fragments: 0,
      discarded_fragments: 0,
      contains_multiple_tasks: false
    },
    decisions: [],
    fallback: {
      type: "none" as const,
      message: null
    }
  };
}

function buildCoverage(partial = false): RequirementCoverageReport {
  return {
    requirements_total: 1,
    requirements_covered: partial ? 0 : 1,
    requirements_uncovered: partial ? ["R1"] : [],
    requirements_partially_covered: partial ? ["R1"] : [],
    clarification_needed_for: [],
    out_of_scope_requirements: []
  };
}

function buildGrounding(status: AnswerGroundingCheck["status"]): AnswerGroundingCheck {
  return {
    status,
    route_subject_match: true,
    missing_requirements: status === "partial" ? ["R1"] : [],
    reasons: status === "partial" ? ["Coverage is partial for problem-focused analysis."] : [],
    why_included_summary: ["synthetic-test"],
    selection_reason_summary: ["synthetic-test"]
  };
}

function buildProblemUnit(input: {
  id: string;
  type: ProblemUnit["problem_unit_type"];
  confidenceGrade: "low" | "medium" | "high";
  severityGrade: "low" | "medium" | "high";
  mechanism: string;
}): ProblemUnit {
  return {
    schema_version: "problem_unit_v0_1",
    problem_unit_id: input.id,
    problem_unit_type: input.type,
    title: "Broken chain segment detected",
    mechanism_summary: input.mechanism,
    business_defect_class: "failed_edge:payment_to_settlement",
    severity: {
      score: input.severityGrade === "high" ? 0.8 : input.severityGrade === "medium" ? 0.6 : 0.3,
      grade: input.severityGrade
    },
    confidence: {
      score: input.confidenceGrade === "high" ? 0.8 : input.confidenceGrade === "medium" ? 0.6 : 0.3,
      grade: input.confidenceGrade
    },
    affected_entities: ["Document:DOC-1", "Counterparty:CP-1"],
    affected_documents: ["Document:DOC-1"],
    affected_postings: ["Posting:POST-1"],
    affected_accounts: ["60"],
    affected_counterparties: ["Counterparty:CP-1"],
    affected_contracts: ["Contract:CTR-1"],
    failed_expected_edge: "payment_to_settlement",
    period_impact: {
      is_period_sensitive: true,
      impact_class: "close_risk"
    },
    evidence_pack: ["cand-1"],
    entity_backlinks: [{ entity: "Document", id: "DOC-1" }],
    snapshot_limitations: []
  };
}

function buildProblemSummary(units: ProblemUnit[]): ProblemUnitSummary {
  const unitTypes = Array.from(new Set(units.map((item) => item.problem_unit_type)));
  const typeDistribution: Partial<Record<ProblemUnit["problem_unit_type"], number>> = {};
  const severityDistribution = { low: 0, medium: 0, high: 0 };
  const confidenceDistribution = { low: 0, medium: 0, high: 0 };
  for (const unit of units) {
    typeDistribution[unit.problem_unit_type] = (typeDistribution[unit.problem_unit_type] ?? 0) + 1;
    severityDistribution[unit.severity.grade] += 1;
    confidenceDistribution[unit.confidence.grade] += 1;
  }
  return {
    schema_version: "problem_unit_summary_v0_1",
    units_total: units.length,
    duplicate_collapses: 0,
    unit_types: unitTypes,
    type_distribution: typeDistribution,
    severity_distribution: severityDistribution,
    confidence_distribution: confidenceDistribution,
    primary_unit_type: unitTypes[0] ?? null
  };
}

function buildRetrievalResult(input: {
  broad: boolean;
  minimumEvidenceFailed: boolean;
  degradedTo: "partial" | "clarification" | null;
  narrowing: "weak" | "medium" | "strong";
  confidence: UnifiedRetrievalResult["confidence"];
  limitationReason: "missing_mechanism" | "weak_source_mapping" | null;
  problemUnits: ProblemUnit[];
}): UnifiedRetrievalResult {
  const problemSummary = buildProblemSummary(input.problemUnits);
  return {
    fragment_id: "F1",
    requirement_ids: ["R1"],
    route: "hybrid_store_plus_live",
    status: "ok",
    result_type: "chain",
    items: [
      {
        counterparty_id: "CP-1",
        operations_count: 4,
        document_refs_count: 2
      }
    ],
    raw_entities: [],
    candidate_evidence: [],
    problem_units: input.problemUnits,
    problem_unit_summary: problemSummary,
    summary: {
      broad_query_detected: input.broad,
      broad_result_flag: input.broad,
      minimum_evidence_failed: input.minimumEvidenceFailed,
      degraded_to: input.degradedTo,
      narrowing_strength: input.narrowing
    },
    evidence: [
      {
        evidence_id: "ev-1",
        claim_ref: "requirement:R1",
        source_type: "retrieval_item",
        source_ref: {
          schema_version: "evidence_source_ref_v1",
          namespace: "snapshot_2020",
          entity: "Document",
          id: "DOC-1",
          period: "2020-06",
          canonical_ref: "evidence_source_ref_v1|snapshot_2020|document|doc-1|2020-06"
        },
        pointer: {
          fragment_id: "F1",
          route: "hybrid_store_plus_live",
          source: {
            namespace: "snapshot_2020",
            entity: "Document",
            id: "DOC-1",
            period: "2020-06"
          },
          locator: {
            field_path: "risk_score",
            item_index: 0
          }
        },
        evidence_kind: "mechanism_link",
        mechanism_note: input.limitationReason === "missing_mechanism" ? null : "failed_edge=payment_to_settlement",
        confidence: input.confidence,
        limitation:
          input.limitationReason === null
            ? null
            : {
                reason_code: input.limitationReason,
                note: null
              },
        payload: {
          risk_score: 4
        }
      }
    ],
    why_included: ["synthetic-test"],
    selection_reason: ["synthetic-test"],
    risk_factors: ["broken_chain"],
    business_interpretation: ["synthetic-test"],
    confidence: input.confidence,
    limitations: input.limitationReason ? ["Synthetic limitation for weak evidence."] : [],
    errors: []
  };
}

describe("assistant problem-centric answer mode v1", () => {
  it("uses problem-centric answer mode on problem-heavy case when flag is ON", () => {
    const units = [
      buildProblemUnit({
        id: "pu-1",
        type: "broken_chain_segment",
        confidenceGrade: "medium",
        severityGrade: "high",
        mechanism: "Mechanism candidate: failed_edge:payment_to_settlement."
      })
    ];
    const retrieval = buildRetrievalResult({
      broad: true,
      minimumEvidenceFailed: false,
      degradedTo: "partial",
      narrowing: "weak",
      confidence: "medium",
      limitationReason: null,
      problemUnits: units
    });

    const output = composeAssistantAnswer({
      userMessage: "Покажи разрывы цепочки и хвосты по расчетам за 2020-06.",
      routeSummary: buildRouteSummary(),
      retrievalResults: [retrieval],
      requirements: [
        {
          requirement_id: "R1",
          source_fragment_id: "F1",
          requirement_text: "Проверить дефекты цепочки",
          subject_tokens: ["chain", "account_60"],
          status: "covered",
          route: "hybrid_store_plus_live"
        }
      ],
      coverageReport: buildCoverage(true),
      groundingCheck: buildGrounding("partial"),
      enableAnswerPolicyV11: true,
      enableProblemCentricAnswerV1: true
    });

    expect(output.problem_centric_answer_applied).toBe(true);
    expect(output.problem_answer_mode).toBe("stage2_problem_centric_v1");
    expect(output.problem_units_used_count).toBeGreaterThan(0);
    expect(output.problem_unit_ids_used).toContain("pu-1");
    expect(output.answer_structure_v11?.answer_summary).toContain("problem-first");
  });

  it("falls back to Stage 1 path for the same case when problem-centric flag is OFF", () => {
    const units = [
      buildProblemUnit({
        id: "pu-1",
        type: "broken_chain_segment",
        confidenceGrade: "medium",
        severityGrade: "high",
        mechanism: "Mechanism candidate: failed_edge:payment_to_settlement."
      })
    ];
    const retrieval = buildRetrievalResult({
      broad: true,
      minimumEvidenceFailed: false,
      degradedTo: "partial",
      narrowing: "weak",
      confidence: "medium",
      limitationReason: null,
      problemUnits: units
    });

    const output = composeAssistantAnswer({
      userMessage: "Покажи разрывы цепочки и хвосты по расчетам за 2020-06.",
      routeSummary: buildRouteSummary(),
      retrievalResults: [retrieval],
      requirements: [
        {
          requirement_id: "R1",
          source_fragment_id: "F1",
          requirement_text: "Проверить дефекты цепочки",
          subject_tokens: ["chain", "account_60"],
          status: "covered",
          route: "hybrid_store_plus_live"
        }
      ],
      coverageReport: buildCoverage(true),
      groundingCheck: buildGrounding("partial"),
      enableAnswerPolicyV11: true,
      enableProblemCentricAnswerV1: false
    });

    expect(output.problem_centric_answer_applied).toBe(false);
    expect(output.problem_answer_mode).toBe("stage1_policy_v11");
    expect(output.answer_structure_v11?.answer_summary).not.toContain("problem-first");
  });

  it("keeps focused grounded case on Stage 1 path even when problem-centric flag is ON", () => {
    const units = [
      buildProblemUnit({
        id: "pu-1",
        type: "broken_chain_segment",
        confidenceGrade: "high",
        severityGrade: "high",
        mechanism: "Mechanism candidate: failed_edge:payment_to_settlement."
      })
    ];
    const retrieval = buildRetrievalResult({
      broad: false,
      minimumEvidenceFailed: false,
      degradedTo: null,
      narrowing: "strong",
      confidence: "high",
      limitationReason: null,
      problemUnits: units
    });

    const output = composeAssistantAnswer({
      userMessage: "Проверь счет 60 за 2020-06 по конкретному контрагенту и покажи подтвержденный дефект.",
      routeSummary: buildRouteSummary(),
      retrievalResults: [retrieval],
      requirements: [
        {
          requirement_id: "R1",
          source_fragment_id: "F1",
          requirement_text: "Проверить конкретный дефект",
          subject_tokens: ["account_60", "counterparty", "document"],
          status: "covered",
          route: "hybrid_store_plus_live"
        }
      ],
      coverageReport: buildCoverage(false),
      groundingCheck: buildGrounding("grounded"),
      enableAnswerPolicyV11: true,
      enableProblemCentricAnswerV1: true
    });

    expect(output.problem_centric_answer_applied).toBe(false);
    expect(output.problem_answer_mode).toBe("stage1_policy_v11");
    expect(output.reply_type).toBe("factual_with_explanation");
  });

  it("enables problem-centric mode on mixed focused case when weak mechanism signals are present", () => {
    const units = [
      buildProblemUnit({
        id: "pu-doc-1",
        type: "document_conflict",
        confidenceGrade: "medium",
        severityGrade: "medium",
        mechanism: "Mechanism candidate: document_conflict_in_chain."
      })
    ];
    const retrieval = buildRetrievalResult({
      broad: false,
      minimumEvidenceFailed: false,
      degradedTo: null,
      narrowing: "strong",
      confidence: "medium",
      limitationReason: "missing_mechanism",
      problemUnits: units
    });

    const output = composeAssistantAnswer({
      userMessage: "Проверь конфликт документа по счету 60 за 2020-06 и оцени влияние.",
      routeSummary: buildRouteSummary(),
      retrievalResults: [retrieval],
      requirements: [
        {
          requirement_id: "R1",
          source_fragment_id: "F1",
          requirement_text: "Проверить конфликт документа",
          subject_tokens: ["account_60", "document"],
          status: "covered",
          route: "hybrid_store_plus_live"
        }
      ],
      coverageReport: buildCoverage(false),
      groundingCheck: buildGrounding("grounded"),
      enableAnswerPolicyV11: true,
      enableProblemCentricAnswerV1: true
    });

    expect(output.problem_centric_answer_applied).toBe(true);
    expect(output.problem_answer_mode).toBe("stage2_problem_centric_v1");
    expect(output.problem_units_used_count).toBeGreaterThan(0);
  });

  it("does not expose raw technical refs in primary problem-centric text", () => {
    const units = [
      buildProblemUnit({
        id: "pu-1",
        type: "period_risk_cluster",
        confidenceGrade: "medium",
        severityGrade: "high",
        mechanism: "Mechanism candidate: failed_edge:payment_to_settlement."
      })
    ];
    const retrieval = buildRetrievalResult({
      broad: true,
      minimumEvidenceFailed: false,
      degradedTo: "partial",
      narrowing: "weak",
      confidence: "medium",
      limitationReason: null,
      problemUnits: units
    });

    const output = composeAssistantAnswer({
      userMessage: "Оцени влияние проблем по расчетам на закрытие периода.",
      routeSummary: buildRouteSummary(),
      retrievalResults: [retrieval],
      requirements: [
        {
          requirement_id: "R1",
          source_fragment_id: "F1",
          requirement_text: "Оценить влияние на закрытие периода",
          subject_tokens: ["period", "account_60"],
          status: "covered",
          route: "hybrid_store_plus_live"
        }
      ],
      coverageReport: buildCoverage(true),
      groundingCheck: buildGrounding("partial"),
      enableAnswerPolicyV11: true,
      enableProblemCentricAnswerV1: true
    });

    expect(output.problem_centric_answer_applied).toBe(true);
    const primaryText = String(output.assistant_reply).split("Evidence block:")[0];
    expect(primaryText).not.toContain("evidence_source_ref_v1|");
    expect(primaryText).not.toContain("cand-");
  });

  it("produces limited answer for weak problem units without false overclaim", () => {
    const units = [
      buildProblemUnit({
        id: "pu-weak-1",
        type: "broken_chain_segment",
        confidenceGrade: "low",
        severityGrade: "low",
        mechanism: "Mechanism is currently inferred at baseline level for broken_chain_segment."
      })
    ];
    const retrieval = buildRetrievalResult({
      broad: true,
      minimumEvidenceFailed: false,
      degradedTo: "partial",
      narrowing: "weak",
      confidence: "low",
      limitationReason: "missing_mechanism",
      problemUnits: units
    });

    const output = composeAssistantAnswer({
      userMessage: "Покажи проблемные зоны по расчетам без детализации.",
      routeSummary: buildRouteSummary(),
      retrievalResults: [retrieval],
      requirements: [
        {
          requirement_id: "R1",
          source_fragment_id: "F1",
          requirement_text: "Выделить проблемные зоны",
          subject_tokens: ["anomaly"],
          status: "covered",
          route: "hybrid_store_plus_live"
        }
      ],
      coverageReport: buildCoverage(true),
      groundingCheck: buildGrounding("partial"),
      enableAnswerPolicyV11: true,
      enableProblemCentricAnswerV1: true
    });

    expect(output.problem_centric_answer_applied).toBe(true);
    expect(output.answer_structure_v11?.mechanism_block.status).not.toBe("grounded");
    expect(output.answer_structure_v11?.uncertainty_block.limitations.join(" ")).toMatch(/limited|огранич/i);
    expect(output.answer_structure_v11?.direct_answer).toMatch(/limited|огранич|предвар|частич/i);
  });
});