module Main where

import qualified Bril as B
import Data.Aeson (eitherDecode, decode, toJSON, parseJSON, Result(..))
import Data.Aeson.Types (parse)
import Data.Text
import Data.Maybe
import Data.Function ((&))

import Test.HUnit
import qualified System.Exit as Exit
 
testTypes :: Test
testTypes = TestCase $ do
    assertEqual "int type" (decode "\"int\"" :: Maybe B.Type) (Just B.Int)
    assertEqual "bool type" (decode "\"bool\"" :: Maybe B.Type) (Just B.Bool)

testLiterals :: Test
testLiterals = TestCase $ do
    assertEqual "true literal"
        (parseLiteral B.Bool "true") (Success $ B.BoolValue True)
    assertEqual "false literal"
        (parseLiteral B.Bool "false") (Success $ B.BoolValue False)
    assertEqual "wrong bool literal"
        (parseLiteral B.Bool "xxx") (Error "invalid bool literal: xxx")

    assertEqual "int literal"
        (parseLiteral B.Int "1434") (Success $ B.IntValue 1434)
    assertEqual "negative int literal"
        (parseLiteral B.Int "-143443") (Success $ B.IntValue (- 143443))
    assertEqual "wrong int literal"
        (parseLiteral B.Int "123xz") (Error "invalid int literal: 123xz")
    assertEqual "wrong int literal"
        (parseLiteral B.Int "123.5") (Error "invalid int literal: 123.5")
    assertEqual "wrong int literal"
        (parseLiteral B.Int "123.5") (Error "invalid int literal: 123.5")

    where
        parseLiteral type_ x = (parse (B.parseValue type_) (toJSON (x::Text)))

testInstrs :: Test
testInstrs = TestCase $ do
    assertEqual "add instr"
        (eitherDecode "{\"op\": \"add\", \"type\": \"int\", \"dest\": \"x\", \"args\": [\"a\", \"b\"]}")
        (Right $ B.ValueInstr B.Add B.Int "x" ["a", "b"] [] [])

    assertEqual "sub instr"
        (decode "{\"op\": \"sub\", \"type\": \"int\", \"dest\": \"x\", \"args\": [\"a\", \"b\"]}")
        (Just $ B.ValueInstr B.Sub B.Int "x" ["a", "b"] [] [])

    assertEqual "wrong instr"
        (eitherDecode "{\"op\": \"wrnog\", \"type\": \"int\", \"dest\": \"x\", \"args\": [\"a\", \"b\"]}")
        (Left "Error in $: Invalid op: wrnog" :: Either String B.Instruction)

    assertEqual "wrong arity"
        (eitherDecode "{\"op\": \"add\", \"type\": \"int\", \"dest\": \"x\", \"args\": [\"b\"]}")
        (Left "Error in $: wrong arity for add: got 1, 0" :: Either String B.Instruction)

    assertEqual "wrong label arity"
        (eitherDecode "{\"op\": \"add\", \"type\": \"int\", \"dest\": \"x\", \"args\": [\"a\", \"b\"], \"labels\": [\"a\"]}")
        (Left "Error in $: wrong arity for add: got 2, 1" :: Either String B.Instruction)

    assertEqual "parse effect call"
        (eitherDecode "{\"op\": \"call\", \"args\": [\"a\", \"b\"], \"funcs\": [\"a\"]}")
        (Right $ B.EffectInstr B.Call ["a", "b"] ["a"] [])

    assertEqual "parse value call"
        (eitherDecode "{\"op\": \"call\", \"type\": \"bool\", \"dest\": \"z\", \"args\": [\"a\", \"b\"], \"funcs\": [\"a\"]}")
        (Right $ B.ValueInstr B.Call B.Bool "z" ["a", "b"] ["a"] [])

    assertEqual "parse invalid call"
        (eitherDecode "{\"op\": \"call\", \"type\": \"bool\", \"dest\": \"z\", \"args\": [\"a\", \"b\"], \"funcs\": []}")
        (Left "Error in $: call op must have exactly one entry in \"funcs\"" :: Either String B.Instruction)

    assertEqual "parse jmp"
        (eitherDecode "{\"op\": \"jmp\", \"labels\": [\"a\"]}")
        (Right $ B.EffectInstr B.Jmp [] [] ["a"])

    assertEqual "parse br"
        (eitherDecode "{\"op\": \"br\", \"labels\": [\"a\", \"b\"], \"args\": [\"z\"]}")
        (Right $ B.EffectInstr B.Br ["z"] [] ["a", "b"])

tests :: Test
tests = TestList [
        TestLabel "bril parser: type" testTypes,
        TestLabel "bril parser: literal" testLiterals,
        TestLabel "bril parser: instruction" testInstrs
    ]
 
main :: IO ()
main = do
    result <- runTestTT tests
    if failures result > 0 then Exit.exitFailure else Exit.exitSuccess