/* tslint:disable:no-unused-expression */
import { expect } from "chai";

import * as AST from "../src/ast";
import { isError } from "../src/error";
import Lexer from "../src/lexer";
import Parser from "../src/parser";

const parse = (source: string): AST.Statement[] => {
  const tokens = new Lexer(source).scan();
  if (isError(tokens)) {
    throw tokens.message;
  } else {
    const tree = new Parser(tokens).parse();
    if (isError(tree)) {
      throw tree.message;
    }
    return tree;
  }
};

describe("Parser", () => {
  it("should parse a number selection", () => {
    const tree = parse("select 5");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Number(5)],
      }),
    ]);
  });

  it("should parse a multiple number selection", () => {
    const tree = parse("select 5, 6");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Number(5), new AST.Number(6)],
      }),
    ]);
  });

  it("should parse a selection of identifiers", () => {
    const tree = parse("select a, b");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a"), new AST.Identifier("b")],
      }),
    ]);
  });

  it("should parse a selection of identifiers and numbers", () => {
    const tree = parse("select a, 5");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a"), new AST.Number(5)],
      }),
    ]);
  });

  it("should parse the from of a selection", () => {
    const tree = parse("select a from t");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Identifier("t"),
      }),
    ]);
  });

  it("should parse aliases", () => {
    const tree = parse("select a as b");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [
          new AST.Alias(new AST.Identifier("a"), new AST.Identifier("b")),
        ],
      }),
    ]);
  });

  it("should parse aliases as from targets", () => {
    const tree = parse("select a from t as u");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Alias(new AST.Identifier("t"), new AST.Identifier("u")),
      }),
    ]);
  });

  it("should not allow a number as a from target", () => {
    const fn = () => parse("select 1 from 2");
    expect(fn).to.throw("Unexpected token: { kind: NUMBER, value: 2 }");
  });

  it("should parse a where with a number", () => {
    const tree = parse("select a from b where 1");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Identifier("b"),
        where: new AST.Number(1),
      }),
    ]);
  });

  it("should parse a where with an identifier", () => {
    const tree = parse("select a from b where c");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Identifier("b"),
        where: new AST.Identifier("c"),
      }),
    ]);
  });

  it("should parse a where with an equality", () => {
    const tree = parse("select a from b where c = d");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Identifier("b"),
        where: new AST.Binary({
          left: new AST.Identifier("c"),
          right: new AST.Identifier("d"),
          type: AST.BinaryExpressionTypes.EQUALITY,
        }),
      }),
    ]);
  });

  it("should parse a where with an addition", () => {
    const tree = parse("select a from b where c + d");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Identifier("b"),
        where: new AST.Binary({
          left: new AST.Identifier("c"),
          right: new AST.Identifier("d"),
          type: AST.BinaryExpressionTypes.ADDITION,
        }),
      }),
    ]);
  });

  it("should parse a where with a subtraction", () => {
    const tree = parse("select a from b where c - d");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Identifier("b"),
        where: new AST.Binary({
          left: new AST.Identifier("c"),
          right: new AST.Identifier("d"),
          type: AST.BinaryExpressionTypes.SUBTRACTION,
        }),
      }),
    ]);
  });

  it("should parse a where with a multiplication", () => {
    const tree = parse("select a from b where c * d");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Identifier("b"),
        where: new AST.Binary({
          left: new AST.Identifier("c"),
          right: new AST.Identifier("d"),
          type: AST.BinaryExpressionTypes.MULTIPLICATION,
        }),
      }),
    ]);
  });

  it("should parse a where with a division", () => {
    const tree = parse("select a from b where c / d");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Identifier("b"),
        where: new AST.Binary({
          left: new AST.Identifier("c"),
          right: new AST.Identifier("d"),
          type: AST.BinaryExpressionTypes.DIVISION,
        }),
      }),
    ]);
  });

  it("should parse a where with a complex binary expression", () => {
    const tree = parse("select a from b where c + d = e");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Identifier("b"),
        where: new AST.Binary({
          left: new AST.Binary({
            left: new AST.Identifier("c"),
            right: new AST.Identifier("d"),
            type: AST.BinaryExpressionTypes.ADDITION,
          }),
          right: new AST.Identifier("e"),
          type: AST.BinaryExpressionTypes.EQUALITY,
        }),
      }),
    ]);
  });

  it("should parse a where with a boolean expression", () => {
    const tree = parse("select a from b where c and d");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Identifier("b"),
        where: new AST.Binary({
          left: new AST.Identifier("c"),
          right: new AST.Identifier("d"),
          type: AST.BinaryExpressionTypes.AND,
        }),
      }),
    ]);
  });

  it("should parse chained ANDs", () => {
    const tree = parse("select a from b where c and d and e");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Identifier("b"),
        where: new AST.Binary({
          left: new AST.Binary({
            left: new AST.Identifier("c"),
            right: new AST.Identifier("d"),
            type: AST.BinaryExpressionTypes.AND,
          }),
          right: new AST.Identifier("e"),
          type: AST.BinaryExpressionTypes.AND,
        }),
      }),
    ]);
  });

  it("should parse chained ORs", () => {
    const tree = parse("select a from b where c or d or e");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Identifier("b"),
        where: new AST.Binary({
          left: new AST.Binary({
            left: new AST.Identifier("c"),
            right: new AST.Identifier("d"),
            type: AST.BinaryExpressionTypes.OR,
          }),
          right: new AST.Identifier("e"),
          type: AST.BinaryExpressionTypes.OR,
        }),
      }),
    ]);
  });

  it("should parse backticked column names", () => {
    const tree = parse("select `a` from b");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Backtick(new AST.Identifier("a"))],
        from: new AST.Identifier("b"),
      }),
    ]);
  });

  it("should not allow unbalanced backticks", () => {
    const fn = () => parse("select `a from b");
    expect(fn).to.throw("Unexpected token: { kind: FROM }");
  });

  it("should parse backticked FROM targets", () => {
    const tree = parse("select a from `b`");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        from: new AST.Backtick(new AST.Identifier("b")),
      }),
    ]);
  });

  it("should parse backticked aliases", () => {
    const tree = parse("select a as `b`");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Alias(new AST.Identifier("a"), new AST.Backtick(new AST.Identifier("b")))],
      }),
    ]);
  });

  it("should parse backticked aliases", () => {
    const tree = parse("select a as `b`");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Alias(new AST.Identifier("a"), new AST.Backtick(new AST.Identifier("b")))],
      }),
    ]);
  });

  it("should parse backticked where operands", () => {
    const tree = parse("select a where `b` = `c`");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [new AST.Identifier("a")],
        where: new AST.Binary({
          left: new AST.Backtick(new AST.Identifier("b")),
          right: new AST.Backtick(new AST.Identifier("c")),
          type: AST.BinaryExpressionTypes.EQUALITY,
        }),
      }),
    ]);
  });

  it("should parse expressions as select arguments", () => {
    const tree = parse("select a = b");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [
          new AST.Binary({
            left: new AST.Identifier("a"),
            right: new AST.Identifier("b"),
            type: AST.BinaryExpressionTypes.EQUALITY,
          }),
        ],
      }),
    ]);
  });

  it("should parse dot operators", () => {
    const tree = parse("select a.b");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [
          new AST.Binary({
            left: new AST.Identifier("a"),
            right: new AST.Identifier("b"),
            type: AST.BinaryExpressionTypes.DOT,
          }),
        ],
      }),
    ]);
  });

  it("should parse parens", () => {
    const tree = parse("select a * (b + c)");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [
          new AST.Binary({
            left: new AST.Identifier("a"),
            right: new AST.Binary({
              left: new AST.Identifier("b"),
              right: new AST.Identifier("c"),
              type: AST.BinaryExpressionTypes.ADDITION,
            }),
            type: AST.BinaryExpressionTypes.MULTIPLICATION,
          }),
        ],
      }),
    ]);
  });

  it("should parse a parenthesized SELECT as a FROM target", () => {
    const tree = parse("select a from (select b)");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [
          new AST.Identifier("a"),
        ],
        from: new AST.SelectStatement({
          arguments: [new AST.Identifier("b")],
        }),
      }),
    ]);
  });

  it("should allow aliases on subselects", () => {
    const tree = parse("select a from (select b) as c");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [
          new AST.Identifier("a"),
        ],
        from: new AST.Alias(
          new AST.SelectStatement({
            arguments: [new AST.Identifier("b")],
          }),
          new AST.Identifier("c"),
        ),
      }),
    ]);
  });

  it("should parse SELECT *", () => {
    const tree = parse("select *");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [
          new AST.Star(),
        ],
      }),
    ]);
  });

  it("should parse * on the right hand side of a dot in a SELECT", () => {
    const tree = parse("select a.*");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [
          new AST.Binary({
            left: new AST.Identifier("a"),
            right: new AST.Star(),
            type: AST.BinaryExpressionTypes.DOT,
          }),
        ],
      }),
    ]);
  });

  it("should parse * on the right of a dot where the left is a backtick", () => {
    const tree = parse("select `a`.*");
    expect(tree).to.deep.equal([
      new AST.SelectStatement({
        arguments: [
          new AST.Binary({
            left: new AST.Backtick(new AST.Identifier("a")),
            right: new AST.Star(),
            type: AST.BinaryExpressionTypes.DOT,
          }),
        ],
      }),
    ]);
  });

  it("should not allow stars in arithmetic operations", () => {
    expect(() => parse("select 1 + *")).to.throw("Unexpected token: { kind: STAR }");
    expect(() => parse("select 1 + a.*")).to.throw("Unexpected token: { kind: STAR }");
    expect(() => parse("select * + 1")).to.throw("Unexpected token: { kind: PLUS }");
    expect(() => parse("select a.* + b.*")).to.throw("Unexpected token: { kind: PLUS }");
    expect(() => parse("select a from b where c.*")).to.throw("Unexpected token: { kind: STAR }");
  });
});