module Language where

import Control.Monad.State (evalState)
import Data.Foldable (find)
import qualified Micro.Ast as A
import Micro.Compiler
import qualified Micro.Error as E
import Micro.Parser (parseFromString)
import Test.HUnit
import Text.Parsec.Pos (newPos)

assertAst :: String -> [A.Expr] -> Assertion
assertAst input expected = do
  r <- return $ parseFromString input
  case r of
    Left e -> assertFailure $ show e
    Right ast -> assertEqual "" expected ast

expectError :: String -> E.ErrorType -> Assertion
expectError input etyp = do
  r <- return $ parseFromString input
  case r of
    Left e -> assertFailure $ show e
    Right ast -> do
      res <- return $ compile ast
      case res of
        Left e -> case (find (\(E.Error t _ _) -> t == etyp) e) of
          Just _ -> return ()
          Nothing -> assertFailure $ "expected " ++ show etyp ++ " didn't happen, got instead:\n" ++ unlines (map (\(E.Error t _ _) -> show t) e)
        Right _ -> assertFailure "expected error, didn't happen"

testCase1 =
  TestLabel "parse module" $
    TestCase $
      assertAst "module main" [A.Module "main" $ newPos "-" 1 1]

testCase2 =
  TestLabel "parse binary number" $
    TestCase $
      assertAst
        "module main\n0b100000;"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Num 32 $ newPos "-" 2 1
        ]

testCase3 =
  TestLabel
    "parse a function"
    $ TestCase $
      assertAst
        "module main\n\
        \def fn() { }"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Func "fn" [] Nothing [] False False $ newPos "-" 2 1
        ]

testCase4 =
  TestLabel
    "parse a function with parameters"
    $ TestCase $
      assertAst
        "module main\n\
        \def fn(a: u8) { }"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Func "fn" [("a", A.Type "u8", True, newPos "-" 2 8)] Nothing [] False False $ newPos "-" 2 1
        ]

testCase5 =
  TestLabel
    "parse a function with return value"
    $ TestCase $
      assertAst
        "module main\n\
        \def fn(): u8 {\n\
        \return 1; }"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Func "fn" [] (Just $ A.Type "u8") [A.Return (Just $ A.Num 1 $ newPos "-" 3 8) $ newPos "-" 3 1] False False $ newPos "-" 2 1
        ]

testCase6 =
  TestLabel
    "parse a function call"
    $ TestCase $
      assertAst
        "module main\n\
        \def fn() { }\n\
        \fn();"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Func "fn" [] Nothing [] False False $ newPos "-" 2 1,
          A.Call (A.Variable "fn" $ newPos "-" 3 1) [] $ newPos "-" 3 1
        ]

testCase7 =
  TestLabel
    "parse a function call with arguments"
    $ TestCase $
      assertAst
        "module main\n\
        \def fn(a: u8) { }\n\
        \fn(10);"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Func "fn" [("a", A.Type "u8", True, newPos "-" 2 8)] Nothing [] False False $ newPos "-" 2 1,
          A.Call (A.Variable "fn" $ newPos "-" 3 1) [A.Num 10 $ newPos "-" 3 4] $ newPos "-" 3 1
        ]

testCase8 =
  TestLabel
    "parse empty return on a function"
    $ TestCase $
      assertAst
        "module main\n\
        \def fn() {\n\
        \return; }"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Func "fn" [] Nothing [A.Return Nothing $ newPos "-" 3 1] False False $ newPos "-" 2 1
        ]

testCase9 =
  TestLabel
    "parse a recursive function"
    $ TestCase $
      assertAst
        "module main\n\
        \def fn() {\n\
        \fn(); }"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Func "fn" [] Nothing [A.Call (A.Variable "fn" $ newPos "-" 3 1) [] $ newPos "-" 3 1] False False $ newPos "-" 2 1
        ]

testCase10 =
  TestLabel
    "parse a function with a function parameter"
    $ TestCase $
      assertAst
        "module main\n\
        \def fn1() { }\n\
        \def fn2(f: ()) {\n\
        \f(); }\n\
        \fn2(fn1);"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Func "fn1" [] Nothing [] False False $ newPos "-" 2 1,
          A.Func
            "fn2"
            [("f", A.FuncType [] Nothing, True, newPos "-" 3 9)]
            Nothing
            [ A.Call (A.Variable "f" $ newPos "-" 4 1) [] $ newPos "-" 4 1
            ]
            False
            False
            $ newPos "-" 3 1,
          A.Call (A.Variable "fn2" $ newPos "-" 5 1) [A.Variable "fn1" $ newPos "-" 5 5] $ newPos "-" 5 1
        ]

testCase11 =
  TestLabel
    "parse a function with a function parameter (lambda)"
    $ TestCase $
      assertAst
        "module main\n\
        \def fn(f: ()) {\n\
        \f(); }\n\
        \fn(() { });"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Func
            "fn"
            [("f", A.FuncType [] Nothing, True, newPos "-" 2 8)]
            Nothing
            [A.Call (A.Variable "f" $ newPos "-" 3 1) [] $ newPos "-" 3 1]
            False
            False
            $ newPos "-" 2 1,
          A.Call (A.Variable "fn" $ newPos "-" 4 1) [A.Func "lambda@4,4" [] Nothing [] True True $ newPos "-" 4 4] $ newPos "-" 4 1
        ]

testCase12 =
  TestLabel "parse a call to lambda" $
    TestCase $
      assertAst
        "module main\n\
        \() { }();"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Call (A.Func "lambda@2,1" [] Nothing [] True True $ newPos "-" 2 1) [] $ newPos "-" 2 1
        ]

testCase13 =
  TestLabel "parse a variable declaration" $
    TestCase $
      assertAst
        "module main\n\
        \var a: u8 = 10;"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Var "a" (A.Type "u8") (A.Num 10 $ newPos "-" 2 13) False $ newPos "-" 2 5
        ]

testCase14 =
  TestLabel "parse a private variable declaration" $
    TestCase $
      assertAst
        "module main\n\
        \private var a: u8 = 10;"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Var "a" (A.Type "u8") (A.Num 10 $ newPos "-" 2 21) True $ newPos "-" 2 13
        ]

testCase15 =
  TestLabel "parse a group variable declaration" $
    TestCase $
      assertAst
        "module main\n\
        \var (a: u8 = 10,\n\
        \b: bool = true);"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Var "a" (A.Type "u8") (A.Num 10 $ newPos "-" 2 14) False $ newPos "-" 2 6,
          A.Var "b" (A.Type "bool") (A.Bool' True $ newPos "-" 3 11) False $ newPos "-" 3 1
        ]

testCase16 =
  TestLabel "parse a group of private variable declaration" $
    TestCase $
      assertAst
        "module main\n\
        \private var (a: u8 = 10,\n\
        \b: bool = true);"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Var "a" (A.Type "u8") (A.Num 10 $ newPos "-" 2 22) True $ newPos "-" 2 14,
          A.Var "b" (A.Type "bool") (A.Bool' True $ newPos "-" 3 11) True $ newPos "-" 3 1
        ]

testCase17 =
  TestLabel "parse assignation" $
    TestCase $
      assertAst
        "module main\n\
        \var a: u8 = 0;\n\
        \a = 10;"
        [ A.Module "main" $ newPos "-" 1 1,
          A.Var "a" (A.Type "u8") (A.Num 0 $ newPos "-" 2 13) False $ newPos "-" 2 5,
          A.BinOp A.Assign (newPos "-" 3 5) (A.Variable "a" $ newPos "-" 3 1) (A.Num 10 $ newPos "-" 3 5)
        ]

-- test errors

testCaseE1 =
  TestLabel "invalid return value (empty return)" $
    TestCase $
      expectError
        "module main\n\
        \def fn(): u8 { return; }"
        E.TypeError

testCaseE2 =
  TestLabel "invalid return value" $
    TestCase $
      expectError
        "module main\n\
        \def fn(): u16 { return 1; }"
        E.TypeError

testCaseE3 =
  TestLabel "return without function" $
    TestCase $
      expectError
        "module main\n\
        \return;"
        E.UnexpectedReturn

testCaseE4 =
  TestLabel "symbol already defined" $
    TestCase $
      expectError
        "module main\n\
        \def fn() { }\n\
        \def fn() { }"
        E.AlreadyDefined

testCaseE5 =
  TestLabel "parameter already defined" $
    TestCase $
      expectError
        "module main\n\
        \def fn(a: u8, a: u8) { }\n"
        E.AlreadyDefined

testCaseE6 =
  TestLabel "call on non callable" $
    TestCase $
      expectError
        "module main\n\
        \def fn(a: u8): u8 { return a(); }\n"
        E.NonCallable

testCaseE7 =
  TestLabel "undefined variable" $
    TestCase $
      expectError
        "module main\n\
        \def fn(a: u8): u8 { return undef; }\n"
        E.Undefined

testCaseE8 =
  TestLabel "lambdas can use local variables only" $
    TestCase $
      expectError
        "module main\n\
        \def fn(a: u8): () -> u8 {\n\
        \return (): u8 { return a; };\n\
        \}\n"
        E.Undefined

testCaseE9 =
  TestLabel "undefined type in function parameters" $
    TestCase $
      expectError
        "module main\n\
        \def fn(a: undef): bool {\n\
        \return true;\n\
        \}\n"
        E.UndefinedType

testCaseE10 =
  TestLabel "undefined type in function return type" $
    TestCase $
      expectError
        "module main\n\
        \def fn(): undef {\n\
        \return true;\n\
        \}\n"
        E.UndefinedType

testCaseE11 =
  TestLabel "already defined variable" $
    TestCase $
      expectError
        "module main\n\
        \var a: u8 = 1; var a: u8 = 1;\n"
        E.AlreadyDefined

testCaseE12 =
  TestLabel "undefined type in variable declaration" $
    TestCase $
      expectError
        "module main\n\
        \var a: undef = 1;\n"
        E.UndefinedType

testCaseE13 =
  TestLabel "type mismatch in variable declaration" $
    TestCase $
      expectError
        "module main\n\
        \var a: bool = 0;\n"
        E.TypeError

testCaseE14 =
  TestLabel "type mismatch in variable declaration (lambda)" $
    TestCase $
      expectError
        "module main\n\
        \var a: bool = (a:u8): u8 { return a; };\n"
        E.TypeError

testCaseE15 =
  TestLabel "invalid assignation target" $
    TestCase $
      expectError
        "module main\n\
        \def fn() { return; }\n\
        \fn() = 10;"
        E.InvalidTarget

testCaseE16 =
  TestLabel "type mismatch in assignation" $
    TestCase $
      expectError
        "module main\n\
        \var a: u8 = 0;\n\
        \a = false;"
        E.TypeError

testCaseE17 =
  TestLabel "type mismatch in binary operator" $
    TestCase $
      expectError
        "module main\n\
        \1 + false;\n"
        E.TypeError

language =
  [ testCase2,
    testCase3,
    testCase4,
    testCase5,
    testCase6,
    testCase7,
    testCase8,
    testCase9,
    testCase10,
    testCase11,
    testCase12,
    testCase13,
    testCase14,
    testCase15,
    testCase16,
    testCase17,
    -- errors
    testCaseE1,
    testCaseE2,
    testCaseE3,
    testCaseE4,
    testCaseE5,
    testCaseE6,
    testCaseE7,
    testCaseE8,
    testCaseE9,
    testCaseE10,
    testCaseE11,
    testCaseE12,
    testCaseE13,
    testCaseE14,
    testCaseE15,
    testCaseE16,
    testCaseE17
  ]