edlin.py

##Created by Joseph Long 2016
##Modified to resemble DOS edlin by David Hunter 2021
##First python project
##Simple Text Editor

import os
import sys
try:
    from pydos_ui import input
except:
    pass


def edlin(passedIn=""):
    global filename
    #global autosave
    global lineNum
    global parseMap

    def chkPath(tstPath):
        validPath = True

        if tstPath == []:
            validPath = True
        else:

            savDir = os.getcwd()

            for path in tstPath:
                if path == "":
                    os.chdir("/")

                elif os.getcwd() == "/" and path == "..":
                    validPath = False
                    break

                elif path == "." or path == "..":
                    os.chdir(path)

                elif path in os.listdir() and (os.stat(path)[0] & (2**15) == 0):
                    os.chdir(path)

                else:
                    validPath = False
                    break

            os.chdir(savDir)

        return(validPath)

    def open_text(name):

        if name == "":
            name = input("Enter file name: ")

        aPath = name.split("/")
        newdir = aPath.pop(-1)

        text = []
        if chkPath(aPath) and newdir in os.listdir(name[0:len(name)-len(newdir)]) and os.stat(name)[0] & (2**15) != 0:
            with open(name,"r") as f:
                for line in f:
                    text.append(line.replace("\n",""))
        else:
            print("Unable to open: "+name+". File not found.")
            name = ""

        return(name,text)

    def proc_text(lineNum,func,strt,end,text):
        if len(text) > 0:
            x = min(max(0,strt),len(text)-1)
            popIndx = x
            staticEnd = max(0,min(end,len(text)-1))
            if x == staticEnd:
                lineNum = staticEnd
            while x <= staticEnd:
                if func == "L":
                    if x == lineNum:
                        print("   *", x, text[x])
                    else:
                        print("    ", x, text[x])
                elif func == "D":
                    text.pop(popIndx)
                    lineNum = popIndx
                x+=1

        return(lineNum,text)

    def save_text(name,text):
        if name == "":
            name = input("Enter file name: ")

        f = open(name, "w")

        for line in text:
            f.write(line + "\n")

        f.close()

        return(name)

    def parseInput(command):

        global parseMap

        cmdList = []
        parseMap = "C"
        cmdFound = False
        cnfrmFound = False
        buildingNum = False
        builtNum =""
        txtParam = ""
        for sChar in command:
            if not cmdFound:
                if sChar not in "0123456789,.+-$?":
                    cmd = sChar.upper()
                    cmdFound = True
                    if buildingNum:
                        cmdList.append(int(builtNum))
                        buildingNum = False
                        builtNum = ""
                        parseMap += "-"
                elif sChar in "0123456789+-":
                    builtNum += sChar
                    buildingNum = True
                elif sChar == "?" and not cmdFound:
                    if not cnfrmFound:
                        parseMap += sChar
                    cnfrmFound = True
                else:
                    if buildingNum:
                        cmdList.append(int(builtNum))
                        buildingNum = False
                        builtNum = ""
                        parseMap += "-"
            else:
                txtParam += sChar

        if txtParam != "":
            cmdList.append(txtParam.strip())
            parseMap += "+"

        if not cmdFound:
            if buildingNum:
                cmdList.append(int(builtNum))
                parseMap += "-"
                cmd = "*"
            else:
                cmd = "#"

        cmdList.insert(0,cmd)
        return cmdList

    def interperit(command,text):
        global filename
        #global autosave
        global lineNum
        global parseMap

        confirmCmd = False
        loop = True
        command_list = parseInput(command)
        #print (lineNum,command_list,parseMap)
        if "?" in parseMap:
            confirmCmd = True
            parseMap = parseMap.replace("?","")

        if command_list[0] == "O":
            if parseMap == "C+":
                (filename,text) = open_text(command_list[1])
            else:
                (filename,text) = open_text(filename)

        elif command_list[0] == "W":
            if parseMap == "C+":
                filename = save_text(command_list[1],text)
            else:
                filename = save_text(filename,text)

        elif command_list[0] == "E":
            if parseMap == "C+":
                filename = save_text(command_list[1],text)
            else:
                filename = save_text(filename,text)
            loop = False

        elif command_list[0] == "Q":
            loop = False

        #elif command_list[0] == "autosave":
        #    if autosave:
        #        autosave = False
        #        print("\tAutosave disabled")
        #    else:
        #        autosave = True
        #        print("\tAutosave enabled")

        elif command_list[0] == "new":
            if len(command_list) > 1:
                filename = save_text(command_list[1][1:],text)
            else:
                filename = save_text(filename,text)

            text[:] = []

        elif command_list[0] == "H":
            print(" ")
            print(" ")
            print("h                      - DISPLAY COMMANDS")
            print("#                      - REPLACE A SINGLE LINE")
            print("[#][,#]d               - DELETE A BLOCK OF LINES")
            print("[#]i                   - INSERT")
            print("[#]a['str']            - APPEND LINES")
            print("[#][,#]l               - LIST LINES")
            print("[#][,#][?]r'str','str' - REPLACE STRING")
            print("[#][,#][?]s'str'       - SEARCH FOR STRING")
            print("o [filename]           - OPEN FILE")
            print("w [filename]           - WRITE FILE")
            print("e [filename]           - SAVE AND QUIT")
            print("q                      - QUIT")

        elif command_list[0] == "L" or command_list[0] == "D":
            if parseMap == "C-":
                (lineNum,text) = proc_text(lineNum,command_list[0],int(command_list[1]),int(command_list[1]),text)
            elif parseMap == "C--":
                (lineNum,text) = proc_text(lineNum,command_list[0],int(command_list[1]),int(command_list[2]),text)
            elif parseMap == "C":
                (lineNum,text) = proc_text(lineNum,command_list[0],0,len(text)-1,text)
            else:
                print("* Wrong command format. use: [#][,#]"+command_list[0].lower())

        elif command_list[0] == "I":
            if parseMap == "C-":
                text.insert(int(command_list[1]), input("."))
            elif parseMap == "C":
                text.insert(lineNum, input("."))
            else:
                print("* Wrong command format. use: [#]i")

        elif command_list[0] == "A":
            if parseMap == "C":
                text.append(input("."))
            elif parseMap == "C-":
                for a in range(0, int(command_list[1])):
                    text.append(input("."))
            elif parseMap == "C+" or parseMap == "C-+":
                strngs = command_list[-1].strip()
                if strngs.count(strngs[0]) !=2:
                    print("* Wrong command format. Use: [#]a 'str'")
                else:
                    strngs = strngs.replace(strngs[0],"")
                    if parseMap == "C+":
                        text.append(strngs)
                    elif parseMap == "C-+":
                        for a in range(0, int(command_list[1])):
                            text.append(strngs)
            else:
                print("* Wrong command format, use: [#]a 'str'")

        elif command_list[0] == "R":
            strt = lineNum
            if parseMap == "C+":
                strt = lineNum
                end = lineNum
            elif parseMap == "C-+":
                strt = int(command_list[1])
                end = strt
            elif parseMap == "C--+":
                strt = int(command_list[1])
                end = int(command_list[2])
            else:
                print("* Wrong command format. Use: [#][,#][?]r 'str1','str2'")
                strt = -1

            if strt != -1:
                strngs = command_list[-1].strip()
                delim = strngs[0]
                if strngs.count(delim) != 4:
                    print("* Wrong command format. Use: [#][,#][?]r 'str1','str2'")
                else:

                    x = 0
                    token = []
                    delimFound = True
                    for achar in strngs:
                        if achar == delim:
                            if delimFound:
                                strtTk = x+1
                            else:
                                endTk = x
                                token.append(strngs[strtTk:endTk])
                            delimFound = not delimFound
                        x += 1
                    if confirmCmd:
                        print("for lines:",strt,"to",end,"- replace:",token[0],"with:",token[1],":")
                    for b in range(strt, end+1):
                        if confirmCmd:
                            print(text[b].replace(token[0], token[1]))
                            if input("Confirm change (y/n): ")[0].upper() == "Y":
                                text[b] = text[b].replace(token[0], token[1])
                        else:
                            text[b] = text[b].replace(token[0], token[1])

        elif command_list[0] == "S":
            strt = lineNum
            if parseMap == "C+":
                strt = 0
                end = len(text) - 1
            elif parseMap == "C-+":
                strt = int(command_list[1])
                end = strt
            elif parseMap == "C--+":
                strt = int(command_list[1])
                end = int(command_list[2])
            else:
                print("* Wrong command format. Use: [#][,#][?]s 'str'")
                strt = -1

            if strt != -1:
                strngs = command_list[-1].strip()
                if strngs.count(strngs[0]) !=2:
                    print("* Wrong command format. Use: [#][,#][?]s 'str'")
                else:
                    strngs = strngs.replace(strngs[0],"")
                    for b in range(strt, end+1):
                        if text[b].count(strngs) > 0:
                            lineNum = b
                            proc_text(lineNum,"L",b,b,text)
                            if not confirmCmd:
                                break
                            else:
                                if input("Confirm find (y/n): ")[0].upper() == "Y":
                                    break

        elif command_list[0] in "*#":
            if command_list[0] == "*":
                lineNum = min(len(text)-1,max(0,command_list[1]))
            proc_text(lineNum,"L",lineNum,lineNum,text)
            strngs = input(".")
            if strngs != "":
                text.insert(lineNum,strngs)
                if lineNum < len(text)-1:
                    text.pop(lineNum+1)

            if lineNum < len(text):
                lineNum += 1

        return(loop,text)

    #autosave = False
    filename = ""
    lineNum = 0
    text = []

    if passedIn != "":
        (filename,text) = open_text(passedIn)

    print("h for command list")

    loop = True
    while loop:
        (loop,text) = interperit(input(filename+": "),text)
        #if autosave and filename !="":
            #filename = save_text(filename,text)

    del filename
    #del autosave
    del lineNum
    del parseMap


if __name__ != "PyDOS":
    passedIn = ""

edlin(passedIn)