/**
 * rigor/chain-rule.test.js — js-rigor property tests for ChainRule.
 *
 * ChainRule follows a chain of relations and collects values along the path.
 * Properties verified:
 *
 *   - Empty steps → possibility=0, reason='no_chain_steps_defined'
 *   - Empty graph (no relations) → possibility=0
 *   - 1-step chain with matching relation → possibility > 0
 *   - 2-step chain through intermediate node → possibility > 0
 *   - result.possibility ∈ [0, 1]
 *   - bypassPLTC: true skips reachability check
 */
import { describe, it } from 'node:test';
import assert from 'node:assert/strict';
import { rigor } from '@rigor/core';
import { Arbiter } from '../../src/index.js';
import { ChainRule } from '../../src/authorization/rules/ChainRule.js';

describe('ChainRule evaluation (rigor)', () => {
  it('empty steps → possibility=0, reason=no_chain_steps_defined', async () => {
    async function check() {
      const arbiter = new Arbiter();
      arbiter.addNode('user:alice', 'user');
      arbiter.addNode('doc:secret', 'doc');
      const rule = new ChainRule(arbiter);
      const userId = arbiter.resolveNodeId('user:alice');
      const objectId = arbiter.resolveNodeId('doc:secret');
      const result = rule._evaluateRule(
        userId, 'user:alice', objectId, 'doc:secret',
        { type: 'chain', steps: [] },
        new Set(),
        null,
        { includeMeta: true, bypassPLTC: true }
      );
      if (result.possibility !== 0) {
        throw new Error(`expected 0 for empty steps, got ${result.possibility}`);
      }
      if (result.reason !== 'no_chain_steps_defined') {
        throw new Error(`expected reason='no_chain_steps_defined', got '${result.reason}'`);
      }
      return result;
    }

    const report = await rigor.campaign(
      [rigor.fn('check', check, rigor.args())],
      rigor.crucible([
        rigor.invariant('empty-steps', ({ error, errorMessage }) => !error && !errorMessage)
      ])
    ).run({ effort: 200 });

    if (process.env.TEST_DEBUG === '1') console.log(report.toTAP());
    const inv = report.crucibleVerdict?.invariants?.find(i => i.name === 'empty-steps');
    assert.ok(inv);
    assert.equal(inv.passed, true, `empty-steps contract violated in ${inv.failureCount} cases`);
  });

  it('result.possibility ∈ [0, 1] with various chain configurations', async () => {
    async function check(strength) {
      const arbiter = new Arbiter();
      arbiter.addNode('user:alice', 'user');
      arbiter.addNode('doc:secret', 'doc');
      arbiter.addRelation('user:alice', 'owner', 'doc:secret', { possibility: strength });
      const rule = new ChainRule(arbiter);
      const userId = arbiter.resolveNodeId('user:alice');
      const objectId = arbiter.resolveNodeId('doc:secret');
      const result = rule._evaluateRule(
        userId, 'user:alice', objectId, 'doc:secret',
        { type: 'chain', steps: [{ relation: 'owner', direction: 'out' }] },
        new Set(),
        null,
        { includeMeta: true, bypassPLTC: true }
      );
      if (result.possibility < 0 || result.possibility > 1) {
        throw new Error(`possibility=${result.possibility} outside [0,1]`);
      }
      return result;
    }

    const report = await rigor.campaign(
      [rigor.fn('check', check,
        rigor.args(rigor.gen.float({ min: 0, max: 1 }))
      )],
      rigor.crucible([
        rigor.invariant('possibility-bounded', ({ error, errorMessage }) => !error && !errorMessage)
      ])
    ).run({ effort: 800 });

    if (process.env.TEST_DEBUG === '1') console.log(report.toTAP());
    const inv = report.crucibleVerdict?.invariants?.find(i => i.name === 'possibility-bounded');
    assert.ok(inv);
    assert.equal(inv.passed, true, `possibility-bounded violated in ${inv.failureCount} cases`);
  });

  it('no matching path in graph → possibility=0', async () => {
    async function check() {
      const arbiter = new Arbiter();
      arbiter.addNode('user:alice', 'user');
      arbiter.addNode('doc:secret', 'doc');
      // No relations at all
      const rule = new ChainRule(arbiter);
      const userId = arbiter.resolveNodeId('user:alice');
      const objectId = arbiter.resolveNodeId('doc:secret');
      const result = rule._evaluateRule(
        userId, 'user:alice', objectId, 'doc:secret',
        { type: 'chain', steps: [{ relation: 'owner', direction: 'out' }] },
        new Set(),
        null,
        { includeMeta: true, bypassPLTC: true }
      );
      if (result.possibility !== 0) {
        throw new Error(`expected 0 with no relations, got ${result.possibility}`);
      }
      return result;
    }

    const report = await rigor.campaign(
      [rigor.fn('check', check, rigor.args())],
      rigor.crucible([
        rigor.invariant('no-path', ({ error, errorMessage }) => !error && !errorMessage)
      ])
    ).run({ effort: 500 });

    if (process.env.TEST_DEBUG === '1') console.log(report.toTAP());
    const inv = report.crucibleVerdict?.invariants?.find(i => i.name === 'no-path');
    assert.ok(inv);
    assert.equal(inv.passed, true, `no-path contract violated in ${inv.failureCount} cases`);
  });

  it('1-step chain with matching relation → possibility > 0', async () => {
    async function check(strength) {
      const arbiter = new Arbiter();
      arbiter.addNode('user:alice', 'user');
      arbiter.addNode('doc:secret', 'doc');
      arbiter.addRelation('user:alice', 'owner', 'doc:secret', { possibility: strength });
      const rule = new ChainRule(arbiter);
      const userId = arbiter.resolveNodeId('user:alice');
      const objectId = arbiter.resolveNodeId('doc:secret');
      const result = rule._evaluateRule(
        userId, 'user:alice', objectId, 'doc:secret',
        { type: 'chain', steps: [{ relation: 'owner', direction: 'out' }] },
        new Set(),
        null,
        { includeMeta: true, bypassPLTC: true }
      );
      if (result.possibility <= 0) {
        throw new Error(`expected possibility>0 with path, got ${result.possibility}`);
      }
      return result;
    }

    const report = await rigor.campaign(
      [rigor.fn('check', check,
        rigor.args(rigor.gen.float({ min: 0.01, max: 1 }))
      )],
      rigor.crucible([
        rigor.invariant('one-step-pos', ({ error, errorMessage }) => !error && !errorMessage)
      ])
    ).run({ effort: 800 });

    if (process.env.TEST_DEBUG === '1') console.log(report.toTAP());
    const inv = report.crucibleVerdict?.invariants?.find(i => i.name === 'one-step-pos');
    assert.ok(inv);
    assert.equal(inv.passed, true, `one-step-pos contract violated in ${inv.failureCount} cases`);
  });

  it('2-step chain through intermediate → possibility > 0 (when both legs exist)', async () => {
    async function check(strength1, strength2) {
      const arbiter = new Arbiter();
      arbiter.addNode('user:alice', 'user');
      arbiter.addNode('team:eng', 'team');
      arbiter.addNode('doc:secret', 'doc');
      arbiter.addRelation('user:alice', 'member_of', 'team:eng', { possibility: strength1 });
      arbiter.addRelation('team:eng', 'has_access', 'doc:secret', { possibility: strength2 });
      const rule = new ChainRule(arbiter);
      const userId = arbiter.resolveNodeId('user:alice');
      const objectId = arbiter.resolveNodeId('doc:secret');
      const result = rule._evaluateRule(
        userId, 'user:alice', objectId, 'doc:secret',
        { type: 'chain', steps: [
          { relation: 'member_of', direction: 'out' },
          { relation: 'has_access', direction: 'out' }
        ] },
        new Set(),
        null,
        { includeMeta: true, bypassPLTC: true }
      );
      // Path exists, so possibility should be > 0
      if (result.possibility <= 0) {
        throw new Error(`expected possibility>0 with 2-step path, got ${result.possibility}`);
      }
      // And it should be bounded by min(strength1, strength2) along the chain
      if (result.possibility > Math.min(strength1, strength2) + 0.01) {
        throw new Error(`possibility=${result.possibility} exceeds chain min(${strength1}, ${strength2})`);
      }
      return result;
    }

    const report = await rigor.campaign(
      [rigor.fn('check', check,
        rigor.args(
          rigor.gen.float({ min: 0.01, max: 1 }),
          rigor.gen.float({ min: 0.01, max: 1 })
        )
      )],
      rigor.crucible([
        rigor.invariant('two-step-chain', ({ error, errorMessage }) => !error && !errorMessage)
      ])
    ).run({ effort: 800 });

    if (process.env.TEST_DEBUG === '1') console.log(report.toTAP());
    const inv = report.crucibleVerdict?.invariants?.find(i => i.name === 'two-step-chain');
    assert.ok(inv);
    assert.equal(inv.passed, true, `two-step-chain contract violated in ${inv.failureCount} cases`);
  });
});