import { createCompanyLeaveProgramContext } from './context';
import type {
  CompanyLeaveProgramContext,
  CompanyLeaveProgramResult,
  CompanyLeaveProgramDefinition,
  CompanyLeaveProgramDefinitionConfig,
  PolicyCondition,
} from './types';

function asArray(value: PolicyCondition | PolicyCondition[] | undefined): PolicyCondition[] {
  if (value === undefined) {
    return [];
  }
  return Array.isArray(value) ? value : [value];
}

export function defineCompanyLeaveProgram(
  config: CompanyLeaveProgramDefinitionConfig,
): CompanyLeaveProgramDefinition {
  const dependsOn = config.dependsOn === undefined ? [] : [...config.dependsOn];
  const capabilities = config.capabilities === undefined ? [] : [...config.capabilities];

  return {
    contractVersion: 'company_leave_program.v1',
    code: config.code,
    displayName: config.displayName,
    jurisdiction: { ...config.jurisdiction },
    dependsOn,

    toResult(
      context: CompanyLeaveProgramContext = createCompanyLeaveProgramContext(),
    ): CompanyLeaveProgramResult {
      const result = config.evaluate(context);
      return {
        contractVersion: 'company_leave_program.v1',
        program: {
          code: config.code,
          displayName: config.displayName,
          ...(config.description === undefined ? {} : { description: config.description }),
          programKind: config.programKind ?? 'COMPANY_POLICY',
          jurisdiction: { ...config.jurisdiction },
          dependsOn,
          capabilities,
        },
        appliesTo: asArray(config.appliesTo?.(context)),
        eligibility: {
          conditions: result.conditions,
          requiredEvidence: result.requiredEvidence,
        },
        ...(result.entitlement === undefined ? {} : { entitlement: result.entitlement }),
        pay: result.pay,
        requirements: result.requirements,
        jobProtection: result.jobProtection,
        diagnostics: result.diagnostics,
      };
    },
  };
}