open Jest
open Reducer_TestHelpers

describe("reducer using mathjs parse", () => {
  // Test the MathJs parser compatibility
  // Those tests show that there is a semantic mapping from MathJs to CodeTree
  // Reducer.parse is called by Reducer.eval
  // See https://mathjs.org/docs/expressions/syntax.html
  // See https://mathjs.org/docs/reference/functions.html

  describe("expressions", () => {
    test("1", () => expectParseToBe("1", "Ok(1)"))
    test("(1)", () => expectParseToBe( "(1)", "Ok(1)"))
    test("1+2", () => expectParseToBe( "1+2", "Ok((:add 1 2))"))
    test("(1+2)", () => expectParseToBe( "1+2", "Ok((:add 1 2))"))
    test("add(1,2)", () => expectParseToBe( "1+2", "Ok((:add 1 2))"))
    test("1+2*3", () => expectParseToBe( "1+2*3", "Ok((:add 1 (:multiply 2 3)))"))
  })
  describe("arrays", () => {
    //Note. () is a empty list in Lisp
    //  The only builtin structure in Lisp is list. There are no arrays
    //  [1,2,3] becomes (1 2 3)
    test("empty", () => expectParseToBe( "[]", "Ok(())"))
    test("[1, 2, 3]", () => expectParseToBe( "[1, 2, 3]", "Ok((1 2 3))"))
    test("['hello', 'world']", () =>
      expectParseToBe( "['hello', 'world']", "Ok(('hello' 'world'))"))
    test("index", () => expectParseToBe("([0,1,2])[1]", "Ok((:$atIndex (0 1 2) (1)))"))
  })
  describe("records", () => {
    test("define", () => expectParseToBe("{a: 1, b: 2}", "Ok((:$constructRecord (('a' 1) ('b' 2))))"))
    test("use", () =>
      expectParseToBe("{a: 1, b: 2}.a", "Ok((:$atIndex (:$constructRecord (('a' 1) ('b' 2))) ('a')))"))
  })
})

describe("eval", () => {
  // All MathJs operators and functions are builtin for string, float and boolean
  // .e.g + - / * > >= < <= == /= not and or
  // See https://mathjs.org/docs/expressions/syntax.html
  // See https://mathjs.org/docs/reference/functions.html
  describe("expressions", () => {
    test("1", () => expectEvalToBe( "1", "Ok(1)"))
    test("1+2", () => expectEvalToBe( "1+2", "Ok(3)"))
    test("(1+2)*3", () => expectEvalToBe( "(1+2)*3", "Ok(9)"))
    test("2>1", () => expectEvalToBe( "2>1", "Ok(true)"))
    test("concat('a ', 'b')", () => expectEvalToBe( "concat('a ', 'b')", "Ok('a b')"))
    test("log(10)", () => expectEvalToBe( "log(10)", "Ok(2.302585092994046)"))
    test("cos(10)", () => expectEvalToBe( "cos(10)", "Ok(-0.8390715290764524)"))
    // TODO more built ins
  })
  describe("arrays", () => {
    //Note. () is a empty list in Lisp
    // The only builtin structure in Lisp is list
    test("empty array", () => expectEvalToBe( "[]", "Ok([])"))
    test("[1, 2, 3]", () => expectEvalToBe( "[1, 2, 3]", "Ok([1, 2, 3])"))
    test("['hello', 'world']", () => expectEvalToBe( "['hello', 'world']", "Ok(['hello', 'world'])"))
    test("index", () => expectEvalToBe("([0,1,2])[1]", "Ok(1)"))
    test("index not found", ()
      => expectEvalToBe("([0,1,2])[10]", "Error(Array index not found: 10)"))
  })
  describe("records", () => {
    test("define", () =>
      expectEvalToBe("{a: 1, b: 2}", "Ok({a: 1, b: 2})"))
    test("index", () =>
      expectEvalToBe("{a: 1}.a", "Ok(1)"))
    test("index not found", () =>
      expectEvalToBe("{a: 1}.b", "Error(Record property not found: b)"))
  })
})

describe("test exceptions", () => {
  test("javascript exception", () =>
    expectEvalToBe( "jsraise('div by 0')", "Error(JS Exception: Error: 'div by 0')"))

  test("rescript exception", () =>
    expectEvalToBe( "resraise()", "Error(TODO: unhandled rescript exception)"))
})