import { BadRequestException, ConflictException, Injectable, NotFoundException } from '@nestjs/common';
import { DataSource } from 'typeorm';
import type { AuthPrincipal, RequestWithContext } from '../common/http/request-context';
import type { CreateInspectionFindingDto } from '../inspection-findings/dto/create-inspection-finding.dto';
import { F3FindingCatalogResolverService } from '../inspection-findings/f3-finding-catalog-resolver.service';
import { InspectionFindingsService } from '../inspection-findings/inspection-findings.service';
import { assertMobileInspector } from '../inspection-operations/mobile-inspector-policy';
import type { CreateFieldFindingDto } from './dto/create-field-finding.dto';

interface DraftActRow {
  id: string;
  code: string;
  status: string;
}

interface FieldFindingGate {
  context: {
    inspection: { id: string; code: string; status: string };
    area: { id: string; code: string; name: string };
    operatorCompany: { id: string; code: string; name: string };
  };
  capture: {
    captureRequired: boolean;
    hasGeometry: boolean;
    creationGpsCaptured: boolean;
    fieldPhotoCount: number;
    readyForFinding: boolean;
  };
}

@Injectable()
export class FieldFindingsService {
  constructor(
    private readonly dataSource: DataSource,
    private readonly catalog: F3FindingCatalogResolverService,
    private readonly findings: InspectionFindingsService,
  ) {}

  async options(
    visitId: string,
    assetId: string,
    actId: string | undefined,
    principal: AuthPrincipal,
  ) {
    const gate = await this.requireGate(visitId, assetId, principal);
    const act = await this.requireDraftAct(visitId, actId);
    const assetIncludedInAct = await this.actContainsAsset(act.id, assetId);
    const [catalog, findings] = await Promise.all([
      this.catalog.listApplicableForAsset(assetId, {}),
      this.findings.listForAct(act.id),
    ]);

    return {
      context: gate.context,
      act,
      capture: gate.capture,
      assetIncludedInAct,
      catalog,
      findings: findings.data.filter((finding) => finding.assetId === assetId),
      canAddAnother: assetIncludedInAct,
      actSelectionMode: actId ? 'EXPLICIT' : 'LEGACY_SINGLE_DRAFT',
    };
  }

  async list(
    visitId: string,
    assetId: string,
    actId: string | undefined,
    principal: AuthPrincipal,
  ) {
    const gate = await this.requireGate(visitId, assetId, principal);
    const act = await this.requireDraftAct(visitId, actId);
    const findings = await this.findings.listForAct(act.id);
    return {
      context: gate.context,
      act,
      capture: gate.capture,
      assetIncludedInAct: await this.actContainsAsset(act.id, assetId),
      data: findings.data.filter((finding) => finding.assetId === assetId),
      actSelectionMode: actId ? 'EXPLICIT' : 'LEGACY_SINGLE_DRAFT',
    };
  }

  async create(
    visitId: string,
    assetId: string,
    dto: CreateFieldFindingDto,
    principal: AuthPrincipal,
    request: RequestWithContext,
  ) {
    const gate = await this.requireGate(visitId, assetId, principal);
    const act = await this.requireDraftAct(visitId, dto.actId);
    if (!await this.actContainsAsset(act.id, assetId)) {
      throw new ConflictException({
        code: 'FIELD_FINDING_ASSET_NOT_IN_ACT',
        message: 'Agregá este Inventario al Acta seleccionada antes de registrar el Hallazgo',
        actId: act.id,
        assetId,
      });
    }
    const payload: CreateInspectionFindingDto = {
      assetId,
      catalogItemId: dto.catalogItemId ?? null,
      customTitle: dto.customTitle ?? null,
      customLegalBasis: dto.customLegalBasis ?? null,
      description: dto.description,
      severity: dto.severity,
      correctionDueOn: dto.correctionDueOn ?? null,
    };
    const finding = await this.findings.create(act.id, payload, principal, request);
    return {
      context: gate.context,
      act,
      capture: gate.capture,
      finding,
      canAddAnother: true,
      actSelectionMode: dto.actId ? 'EXPLICIT' : 'LEGACY_SINGLE_DRAFT',
    };
  }

  private async requireGate(
    visitId: string,
    assetId: string,
    principal: AuthPrincipal,
  ): Promise<FieldFindingGate> {
    assertMobileInspector(principal);
    const [row] = await this.dataSource.query(`
      SELECT
        visit.id AS "visitId",
        visit.code AS "visitCode",
        visit.status AS "visitStatus",
        COALESCE(visit.scope_asset_id, visit.operational_area_id) AS "scopeAssetId",
        visit.operational_area_id AS "areaId",
        area.code AS "areaCode",
        area.name AS "areaName",
        visit.operator_company_id AS "companyId",
        company.code AS "companyCode",
        company.name AS "companyName",
        asset.id AS "assetId",
        asset_type.code AS "assetTypeCode",
        asset.inventory_family_id AS "inventoryFamilyId",
        (
          asset.id=COALESCE(visit.scope_asset_id, visit.operational_area_id)
          OR EXISTS (
            WITH RECURSIVE ancestors AS (
              SELECT id,parent_id FROM assets WHERE id=asset.parent_id
              UNION ALL
              SELECT parent.id,parent.parent_id
              FROM assets parent JOIN ancestors child ON parent.id=child.parent_id
            )
            SELECT 1 FROM ancestors
            WHERE id=COALESCE(visit.scope_asset_id, visit.operational_area_id)
            LIMIT 1
          )
        ) AS "insideScope",
        EXISTS (
          SELECT 1
          FROM area_company_relations relation
          WHERE relation.area_id=visit.operational_area_id
            AND relation.company_id=visit.operator_company_id
            AND relation.relation_role='OPERATOR'
            AND relation.valid_from <= COALESCE(visit.actual_started_at,visit.planned_start_at,visit.created_at)
            AND (
              relation.valid_until IS NULL
              OR relation.valid_until >= COALESCE(visit.actual_started_at,visit.planned_start_at,visit.created_at)
            )
        ) AS "operatorRelationValid",
        EXISTS (
          SELECT 1
          FROM inspection_visit_members member
          WHERE member.visit_id = visit.id
            AND member.user_id = $3::uuid
            AND member.included = true
        ) OR visit.lead_inspector_user_id = $3::uuid AS assigned,
        EXISTS (
          SELECT 1
          FROM inspection_visit_assets link
          WHERE link.visit_id = visit.id
            AND link.asset_id = asset.id
            AND link.included = true
        ) AS selected,
        EXISTS (
          SELECT 1
          FROM asset_field_discoveries discovery
          WHERE discovery.visit_id = visit.id
            AND discovery.asset_id = asset.id
        ) AS "captureRequired",
        EXISTS (
          SELECT 1
          FROM asset_geometries geometry
          WHERE geometry.asset_id = asset.id
        ) AS "hasGeometry",
        EXISTS (
          SELECT 1
          FROM asset_field_capture_events event
          WHERE event.visit_id = visit.id
            AND event.asset_id = asset.id
            AND event.event_type = 'CREATED'
        ) AS "creationGpsCaptured",
        (
          SELECT COUNT(*)::integer
          FROM asset_field_capture_events event
          WHERE event.visit_id = visit.id
            AND event.asset_id = asset.id
            AND event.event_type = 'PHOTO'
        ) AS "fieldPhotoCount"
      FROM inspection_visits visit
      LEFT JOIN assets area ON area.id = visit.operational_area_id
      LEFT JOIN assets company ON company.id = visit.operator_company_id
      LEFT JOIN assets asset ON asset.id = $2::uuid
        AND asset.information_status <> 'INACTIVE'
      LEFT JOIN asset_types asset_type ON asset_type.id=asset.asset_type_id
      WHERE visit.id = $1::uuid
    `, [visitId, assetId, principal.userId]) as Array<{
      visitId: string;
      visitCode: string;
      visitStatus: string;
      scopeAssetId: string | null;
      areaId: string | null;
      areaCode: string | null;
      areaName: string | null;
      companyId: string | null;
      companyCode: string | null;
      companyName: string | null;
      assetId: string | null;
      assetTypeCode: string | null;
      inventoryFamilyId: string | null;
      insideScope: boolean;
      operatorRelationValid: boolean;
      assigned: boolean;
      selected: boolean;
      captureRequired: boolean;
      hasGeometry: boolean;
      creationGpsCaptured: boolean;
      fieldPhotoCount: number;
    }>;

    if (!row) {
      throw new NotFoundException({ code: 'INSPECTION_VISIT_NOT_FOUND', message: 'Inspección no encontrada' });
    }
    if (row.visitStatus !== 'IN_PROGRESS') {
      throw new ConflictException({
        code: 'FIELD_FINDING_VISIT_NOT_IN_PROGRESS',
        message: 'Los Hallazgos sólo pueden registrarse cuando la inspección está en curso',
      });
    }
    if (!row.assigned) {
      throw new ConflictException({
        code: 'FIELD_FINDING_INSPECTOR_NOT_ASSIGNED',
        message: 'El inspector no está asignado a esta inspección',
      });
    }
    if (!row.areaId || !row.companyId || !row.areaCode || !row.areaName || !row.companyCode || !row.companyName) {
      throw new ConflictException({
        code: 'FIELD_FINDING_CONTEXT_REQUIRED',
        message: 'La inspección no tiene Área y Operadora definidas',
      });
    }
    if (!row.operatorRelationValid) {
      throw new ConflictException({
        code: 'FIELD_FINDING_OPERATOR_RELATION_INVALID',
        message: 'La Operadora seleccionada no estaba vinculada al Área para la fecha de esta inspección',
      });
    }
    if (!row.assetId) {
      throw new NotFoundException({
        code: 'FIELD_FINDING_INVENTORY_NOT_FOUND',
        message: 'Registro de Inventario no encontrado',
      });
    }
    const assetTypeCode = String(row.assetTypeCode).toLowerCase();
    if (!['yacimiento', 'instalacion', 'subinstalacion'].includes(assetTypeCode)) {
      throw new BadRequestException({
        code: 'FIELD_FINDING_TARGET_LEVEL_INVALID',
        message: 'Los Hallazgos pueden registrarse sobre Yacimiento, Instalación o Subinstalación',
      });
    }
    if (assetTypeCode !== 'yacimiento' && !row.inventoryFamilyId) {
      throw new ConflictException({
        code: 'FIELD_FINDING_FAMILY_REQUIRED',
        message: 'La Instalación/Subinstalación debe tener una clasificación técnica antes de registrar Hallazgos',
      });
    }
    if (!row.insideScope) {
      throw new BadRequestException({
        code: 'FIELD_FINDING_INVENTORY_OUTSIDE_CONTEXT',
        message: 'El Inventario no pertenece al Yacimiento definido como alcance de esta inspección',
      });
    }
    if (!row.selected) {
      throw new ConflictException({
        code: 'FIELD_FINDING_INVENTORY_NOT_SELECTED',
        message: 'Seleccioná el Inventario dentro de la inspección antes de registrar un Hallazgo',
      });
    }

    const captureRequired = Boolean(row.captureRequired);
    const hasGeometry = Boolean(row.hasGeometry);
    const creationGpsCaptured = Boolean(row.creationGpsCaptured);
    const fieldPhotoCount = Number(row.fieldPhotoCount ?? 0);
    const readyForFinding = !captureRequired || (
      hasGeometry && creationGpsCaptured && fieldPhotoCount > 0
    );
    if (!readyForFinding) {
      throw new ConflictException({
        code: 'FIELD_FINDING_CAPTURE_REQUIRED',
        message: 'Antes del Hallazgo, el Inventario creado en campo debe tener GPS y al menos una foto',
        capture: { captureRequired, hasGeometry, creationGpsCaptured, fieldPhotoCount },
      });
    }

    return {
      context: {
        inspection: { id: row.visitId, code: row.visitCode, status: row.visitStatus },
        area: { id: row.areaId, code: row.areaCode, name: row.areaName },
        operatorCompany: { id: row.companyId, code: row.companyCode, name: row.companyName },
      },
      capture: {
        captureRequired,
        hasGeometry,
        creationGpsCaptured,
        fieldPhotoCount,
        readyForFinding,
      },
    };
  }

  private async actContainsAsset(actId: string, assetId: string): Promise<boolean> {
    const [row] = await this.dataSource.query(`
      SELECT EXISTS (
        SELECT 1 FROM inspection_act_assets
        WHERE act_id=$1::uuid AND asset_id=$2::uuid AND included=true
      ) AS included
    `, [actId, assetId]) as Array<{ included: boolean }>;
    return Boolean(row?.included);
  }

  private async requireDraftAct(visitId: string, requestedActId?: string): Promise<DraftActRow> {
    if (requestedActId) {
      const [act] = await this.dataSource.query(`
        SELECT id,code,status
        FROM inspection_acts
        WHERE id=$1::uuid AND visit_id=$2::uuid
      `, [requestedActId, visitId]) as DraftActRow[];
      if (!act) {
        throw new NotFoundException({
          code: 'FIELD_FINDING_ACT_NOT_FOUND',
          message: 'El Acta seleccionada no pertenece a esta inspección',
        });
      }
      if (act.status !== 'DRAFT') {
        throw new ConflictException({
          code: 'FIELD_FINDING_ACT_NOT_DRAFT',
          message: 'Los Hallazgos nuevos sólo pueden agregarse a un Acta en borrador',
          actId: act.id,
          actStatus: act.status,
        });
      }
      return act;
    }

    const rows = await this.dataSource.query(`
      SELECT id, code, status
      FROM inspection_acts
      WHERE visit_id = $1::uuid
        AND status = 'DRAFT'
      ORDER BY created_at DESC, id DESC
      LIMIT 2
    `, [visitId]) as DraftActRow[];

    if (rows.length === 0) {
      throw new ConflictException({
        code: 'FIELD_FINDING_DRAFT_ACT_REQUIRED',
        message: 'La inspección no tiene un Acta borrador abierta para registrar Hallazgos',
      });
    }
    if (rows.length > 1) {
      throw new ConflictException({
        code: 'FIELD_FINDING_MULTIPLE_DRAFT_ACTS',
        message: 'La inspección tiene más de un Acta borrador. Debe resolverse antes de continuar',
      });
    }
    return rows[0];
  }
}