''' Purpose: produce spell-check corrected text
'''

# get access to url support
import url

# define annotation markers
CORRECTED_WORD_START_MARKER = "*"
CORRECTED_WORD_END_MARKER   = "*"

UNKNOWN_WORD_START_MARKER   = "?"
UNKNOWN_WORD_END_MARKER     = "?"

# CS 1112 most common words
MOST_COMMON_URL = "http://www.cs.virginia.edu/~cs1112/words/most-common"

# CS 1112 words corrections CSV
CORRECTIONS_URL = "http://www.cs.virginia.edu/~cs1112/words/corrections"

# get words from most common words url
good_words = url.get_words( MOST_COMMON_URL ) # new function from url -- hands back
                                              # contents of MOST_COMMON_URL as list
                                              # of words

# get corrections dictionary
misspellings_dictionary  = url.get_dictionary( CORRECTIONS_URL )

# get the user text to be checked

reply = input( "Enter text: " )

# clean up the user response
cleaned_up_reply = reply.strip().lower()      # strip() hands back a stripped string
                                              # to lower(). lower() takes that string
                                              # hands back a string that is both
                                              # lower case and stripped.

# convert cleaned up response  into a list of words from the user
text = cleaned_up_reply.split()

# what now -- accumulate the spell check output of the user text
spell_checked_text = ""

for current_word in text:                     
    # for each word there is one of three possibilities for the word:
    #    it is correctly spelled;
    #    it is incorrectly spelled but the likely correct spelling is known;
    #    or, it is incorrecty spelled and no correction is available.

    # determine which possibility for the word applies to determine its entry
    # to the corrected text.
    if ( current_word in good_words ):
        # correctly spelled -- so the current word is what we want to add to
        # spell checked text
        entry = current_word
    
    elif ( current_word in misspellings_dictionary ):
        # incorrectly spelled -- but a correction is known, so get it
        correction = misspellings_dictionary[ current_word ]

        # its entry is the correction surrounded by the correct markers
        entry = CORRECTED_WORD_START_MARKER + correction + CORRECTED_WORD_END_MARKER

    else : 
        # it is incorrecty spelled and no correction is available. so its entry
        # is the misspelled word surrounded by unknown word markers
        entry = UNKNOWN_WORD_START_MARKER + current_word + UNKNOWN_WORD_END_MARKER

    # to finish off this iteration of the loop, add the entry to the output accumulation
    spell_checked_text = spell_checked_text + entry + " "

# print spell checked result
print( spell_checked_text )                   # outside the loop, so we only print
                                              # when done

# HAVE A GREAT SPRING BREAK