import os
from re import split
import subprocess
from typing import List

from project_man import addLibraryInProject, removeLibraryInProject

def getCfFileId(std: str):
    return "08" if std == "08" else "93" ## Weird behaviour from GHDL, but all vhdl versions besides 08 have [...]93.cf

def ghdlEnvExists(std, lib):
    ## Check if work exists
    try:
        os.lstat("work")
    except:
        return False
    ## Check that work is writable
    if not os.access("work", os.W_OK):
        print("work is write-protected, please acquire correct permissions")
        return False
    cfFileExists = False
    filesInWork = os.listdir("work")
    cfFileId = getCfFileId(std)
    for file in filesInWork:
        if ".cf" in file and lib in file and cfFileId in file:
            cfFileExists = True
    if not cfFileExists:
        return False
    ## Nothing bad, continue
    return True

def addVHDLFiles(fileNames: List[str], std: str, lib: str):
    os.makedirs("work", exist_ok=True)
    vhdlFiles = []
    if ghdlEnvExists(std=std, lib=lib):
        cfFileId = getCfFileId(std)
        cfFileName = list(filter(lambda x: ".cf" in x and lib in x and cfFileId in x, os.listdir("work")))[0]
        cfFilePath = os.path.join("work",cfFileName)
        currentlyAdded = getCurrentlyAddedFiles(cfFilePath)
        for fileName in fileNames:
            if fileName not in currentlyAdded:
                vhdlFiles.append(fileName)
    else:
        addLibraryInProject(lib, ".", std)
        vhdlFiles = fileNames
    vhdlFiles = list(filter(lambda x: ".vhd" in x, vhdlFiles))
    if len(vhdlFiles) == 0:
        print("no files to add.")
        return 0
    print(f"adding {vhdlFiles} to library {lib}")
    command = ["ghdl", "-i", "--workdir=work", f"--work={lib}", f"--std={std}"] + vhdlFiles 
    subprocess.run(command)
    return 0

def removeVHDLFiles(fileNames: List[str], std: str, lib: str):
    if not ghdlEnvExists(std=std, lib=lib):
       return -1
    cfFileId = getCfFileId(std)
    cfFileName = list(filter(lambda x: ".cf" in x and lib in x and cfFileId in x, os.listdir("work")))[0]
    cfFilePath = os.path.join("work",cfFileName)
    currentlyAdded = getCurrentlyAddedFiles(cfFilePath)

    for fileName in fileNames:
        if fileName not in currentlyAdded:
            print(f"file {fileName} is not present in {cfFileName}.")
            return 0
        currentlyAdded.remove(fileName)
        removeCurrentlyAddedFile(fileName, cfFilePath)
    if len(currentlyAdded) == 0:
        print("Project is empty, removing GHDL project file and library reference in project")
        removeLibraryInProject(lib)
        os.remove(cfFilePath)


def getCurrentlyAddedFiles(cfFilePath:str):
    f = open(cfFilePath,"r")
    lines = f.readlines()
    f.close()
    fileLines = filter(lambda x: "file" in x, lines) 
    files = map(lambda x: split("\" \"",x)[1], fileLines)
    return list(files)

def removeCurrentlyAddedFile(fileName: str, cfFilePath: str):
    f = open(cfFilePath,"r")
    lines = f.readlines()
    f.close()
    try:
        mappedLines = list(map(lambda x: fileName in x, lines))
        index = mappedLines.index(True)
        endIndex = len(lines)-1
        for x in range(index+1,len(lines)):
            if "file" in lines[x]:
                endIndex = x
                break
        newLines = []
        for x in range(len(lines)):
            if x < index or x >= endIndex:
                newLines.append(lines[x])
        f = open(cfFilePath, "w")
        f.writelines(newLines)
        f.close()
    except:
        print(f"Something went wrong when trying to remove {fileName} from {cfFilePath}. Restoring to original configuration")
        f = open(cfFilePath, "w")
        f.writelines(lines)
        f.close()