import { expect } from 'chai'
import { Model, loadModule } from '../src/index'

before(() => loadModule())

const TOL = 1e-6

describe('exact', () => {
  it('should solve a simple problem', () => {
    const model = new Model()
    expect(model.sense).to.equal('min')

    const x = model.addVars(2, { lb: 0, obj: 1, name: 'x' })

    const s0 = model.addConstr()
    s0.setBounds(1, 1)
    s0.add([
      [x[0], 1],
      [x[1], 2],
    ])

    expect(model.status).to.equal('undefined')
    expect(model.statusPrimal).to.equal('undefined')
    expect(model.statusDual).to.equal('undefined')

    const code0 = model.exact({ msgLevel: 'off' })
    expect(code0).to.equal('ok')
    expect(model.status).to.equal('optimal')
    expect(model.statusPrimal).to.equal('feasible')
    expect(model.statusDual).to.equal('feasible')
    expect(model.value).to.be.closeTo(0.5, TOL)

    // check primal values
    expect(s0.value).to.be.closeTo(1, TOL)
    expect(x[0].value).to.be.closeTo(0, TOL)
    expect(x[1].value).to.be.closeTo(0.5, TOL)
    // check dual values
    expect(s0.dual).to.be.closeTo(0.5, TOL)
    expect(x[0].dual).to.be.closeTo(0.5, TOL)
    expect(x[1].dual).to.be.closeTo(0, TOL)
    // check status
    expect(x[0].status).to.equal('lower-bound')
    expect(x[1].status).to.equal('basic')
    expect(s0.status).to.equal('fixed')

    model.sense = 'max'
    const code1 = model.exact({ msgLevel: 'off' })
    expect(code1).to.equal('ok')
    expect(model.status).to.equal('optimal')
    expect(model.statusPrimal).to.equal('feasible')
    expect(model.statusDual).to.equal('feasible')
    expect(model.value).to.be.closeTo(1, TOL)

    // check primal values
    expect(s0.value).to.be.closeTo(1, TOL)
    expect(x[0].value).to.be.closeTo(1, TOL)
    expect(x[1].value).to.be.closeTo(0, TOL)
    // check dual values
    expect(s0.dual).to.be.closeTo(1, TOL)
    expect(x[0].dual).to.be.closeTo(0, TOL)
    expect(x[1].dual).to.be.closeTo(-1, TOL)
    // check status
    expect(x[0].status).to.equal('basic')
    expect(x[1].status).to.equal('lower-bound')
    expect(s0.status).to.equal('fixed')

    expect(model.solution).to.equal('status = optimal\nx_0 = 1\nx_1 = 0\nvalue = 1')

    expect(() => model.ray).to.throw(Error, 'no unbounded ray')
  })
})