#!/usr/bin/Rscript

#' Returns file name of calling Rscript
#'
#' \code{get_Rscript_filename} returns the file name of calling Rscript 
#' @return A string with the filename of the calling script.
#'      If not found (i.e. you are in a interactive session) returns NA.
#'
#' @export
get_Rscript_filename <- function() {
    prog <- sub("--file=", "", grep("--file=", commandArgs(), value=TRUE)[1])
    if( .Platform$OS.type == "windows") { 
        prog <- gsub("\\\\", "\\\\\\\\", prog)
    }
    prog
}

#' Recursively sorts a list
#'
#' \code{sort_list} returns a sorted list
#' @param unsorted_list A list.
#' @return A sorted list.
#' @export
sort_list <- function(unsorted_list) {
    for(ii in seq(along=unsorted_list)) {
        if(is.list(unsorted_list[[ii]])) {
            unsorted_list[[ii]] <- sort_list(unsorted_list[[ii]])
        }
    }
    unsorted_list[sort(names(unsorted_list))] 
}

#' #!/path/to/Rscript
#' library('getopt');
#' #get options, using the spec as defined by the enclosed list.
#' #we read the options from the default: commandArgs(TRUE).
#' spec = matrix(c(
#'   'verbose', 'v', 2, "integer",
#'   'help'   , 'h', 0, "logical",
#'   'count'  , 'c', 1, "integer",
#'   'mean'   , 'm', 1, "double",
#'   'sd'     , 's', 1, "double"
#' ), byrow=TRUE, ncol=4);
#' opt = getopt(spec);
#' 
#' # if help was asked for print a friendly message 
#' # and exit with a non-zero error code
#' if ( !is.null(opt$help) ) {
#'   cat(getopt(spec, usage=TRUE));
#'   q(status=1);
#' }
#' 
#' #set some reasonable defaults for the options that are needed,
#' #but were not specified.
#' if ( is.null(opt$mean    ) ) { opt$mean    = 0     }
#' if ( is.null(opt$sd      ) ) { opt$sd      = 1     }
#' if ( is.null(opt$count   ) ) { opt$count   = 10    }
#' if ( is.null(opt$verbose ) ) { opt$verbose = FALSE }
#' 
#' #print some progress messages to stderr, if requested.
#' if ( opt$verbose ) { write("writing...",stderr()); }
#' 
#' #do some operation based on user input.
#' cat(paste(rnorm(opt$count,mean=opt$mean,sd=opt$sd),collapse="\n"));
#' cat("\n");
#' 
#' #signal success and exit.
#' #q(status=0);
getopt = function (spec=NULL,opt=commandArgs(TRUE),command=get_Rscript_filename(),usage=FALSE,debug=FALSE) {

  # littler compatibility - map argv vector to opt
  if (exists("argv", where = .GlobalEnv, inherits = FALSE)) {
    opt = get("argv", envir = .GlobalEnv);
  }

  ncol=4;
  maxcol=6;
  col.long.name    = 1;
  col.short.name   = 2;
  col.has.argument = 3;
  col.mode         = 4;
  col.description  = 5;

  flag.no.argument = 0;
  flag.required.argument = 1;
  flag.optional.argument = 2;

  result = list();
  result$ARGS = vector(mode="character");

  #no spec.  fail.
  if ( is.null(spec) ) {
    stop('argument "spec" must be non-null.');

  #spec is not a matrix.  attempt to coerce, if possible.  issue a warning.
  } else if ( !is.matrix(spec) ) {
    if ( length(spec)/4 == as.integer(length(spec)/4) ) {
      warning('argument "spec" was coerced to a 4-column (row-major) matrix.  use a matrix to prevent the coercion');
      spec = matrix( spec, ncol=ncol, byrow=TRUE );
    } else {
      stop('argument "spec" must be a matrix, or a character vector with length divisible by 4, rtfm.');
    }

  #spec is a matrix, but it has too few columns.
  } else if ( dim(spec)[2] < ncol ) {
    stop(paste('"spec" should have at least ",ncol," columns.',sep=''));

  #spec is a matrix, but it has too many columns.
  } else if ( dim(spec)[2] > maxcol ) {
    stop(paste('"spec" should have no more than ",maxcol," columns.',sep=''));

  #spec is a matrix, and it has some optional columns.
  } else if ( dim(spec)[2] != ncol ) {
    ncol = dim(spec)[2];
  }

  #sanity check.  make sure long names are unique, and short names are unique.
  if ( length(unique(spec[,col.long.name])) != length(spec[,col.long.name]) ) {
    stop(paste('redundant long names for flags (column ',col.long.name,').',sep=''));
  }
  if ( length(na.omit(unique(spec[,col.short.name]))) != length(na.omit(spec[,col.short.name])) ) {
    stop(paste('redundant short names for flags (column ',col.short.name,').',sep=''));
  }
  # convert numeric type to double type
  spec[,4] <- gsub("numeric", "double", spec[,4])

  # if usage=TRUE, don't process opt, but generate a usage string from the data in spec
  if ( usage ) {
    ret = '';
    ret = paste(ret,"Usage: ",command,sep='');
    for ( j in 1:(dim(spec))[1] ) {
      ret = paste(ret,' [-[-',spec[j,col.long.name],'|',spec[j,col.short.name],']',sep='');
      if (spec[j,col.has.argument] == flag.no.argument) {
        ret = paste(ret,']',sep='');
      } else if (spec[j,col.has.argument] == flag.required.argument) {
        ret = paste(ret,' <',spec[j,col.mode],'>]',sep='');
      } else if (spec[j,col.has.argument] == flag.optional.argument) {
        ret = paste(ret,' [<',spec[j,col.mode],'>]]',sep='');
      }
    }
    # include usage strings
    if ( ncol >= 5 ) {
      max.long = max(apply(cbind(spec[,col.long.name]),1,function(x)length(strsplit(x,'')[[1]])));
      ret = paste(ret,"\n",sep='');
      for (j in 1:(dim(spec))[1] ) {
        ret = paste(ret,sprintf(paste("    -%s|--%-",max.long,"s    %s\n",sep=''),
          spec[j,col.short.name],spec[j,col.long.name],spec[j,col.description]
        ),sep='');
      }
    }
    else {
      ret = paste(ret,"\n",sep='');
    }
    return(ret);
  }

  #XXX check spec validity here.  e.g. column three should be convertible to integer

  i = 1;

  while ( i <= length(opt) ) {
    if ( debug ) print(paste("processing",opt[i]));

    current.flag = 0; #XXX use NA
    optstring = opt[i];


    #long flag
    if ( substr(optstring, 1, 2) == '--' ) {
      if ( debug ) print(paste("  long option:",opt[i]));

      optstring = substring(optstring,3);

      this.flag = NA;
      this.argument = NA;
      kv = strsplit(optstring, '=')[[1]];
      if ( !is.na(kv[2]) ) {
        this.flag = kv[1];
        this.argument = paste(kv[-1], collapse="=");
      } else {
        this.flag = optstring;
      }

      rowmatch = grep( this.flag, spec[,col.long.name],fixed=TRUE );

      #long flag is invalid, matches no options
      if ( length(rowmatch) == 0 ) {
        stop(paste('long flag "', this.flag, '" is invalid', sep=''));

      #long flag is ambiguous, matches too many options
      } else if ( length(rowmatch) > 1 ) {
        # check if there is an exact match and use that
        rowmatch = which(this.flag == spec[,col.long.name])
        if(length(rowmatch) == 0) {
          stop(paste('long flag "', this.flag, '" is ambiguous', sep=''));
        }
      }

      #if we have an argument
      if ( !is.na(this.argument) ) {
        #if we can't accept the argument, bail out
        if ( spec[rowmatch, col.has.argument] == flag.no.argument ) {
          stop(paste('long flag "', this.flag, '" accepts no arguments', sep=''));

        #otherwise assign the argument to the flag
        } else {
          storage.mode(this.argument) = spec[rowmatch, col.mode];
          result[spec[rowmatch, col.long.name]] = this.argument;
	  i = i + 1;
	  next;
        }

      #otherwise, we don't have an argument
      } else {
        #if we require an argument, bail out
        ###if ( spec[rowmatch, col.has.argument] == flag.required.argument ) {
        ###  stop(paste('long flag "', this.flag, '" requires an argument', sep=''));

        #long flag has no attached argument. set flag as present.  set current.flag so we can peek ahead later and consume the argument if it's there
        ###} else {
          result[spec[rowmatch, col.long.name]] = TRUE;
          current.flag = rowmatch;
        ###}
      }

    #short flag(s)
    } else if ( substr(optstring, 1, 1) == '-' ) {
      if ( debug ) print(paste("  short option:",opt[i]));

      these.flags = strsplit(optstring,'')[[1]];

      done = FALSE;
      for ( j in 2:length(these.flags) ) {
        this.flag = these.flags[j];
        rowmatch = grep( this.flag, spec[,col.short.name],fixed=TRUE );

        #short flag is invalid, matches no options
        if ( length(rowmatch) == 0 ) {
          stop(paste('short flag "', this.flag, '" is invalid', sep=''));

        #short flag is ambiguous, matches too many options
        } else if ( length(rowmatch) > 1 ) {
          stop(paste('short flag "', this.flag, '" is ambiguous', sep=''));

        #short flag has an argument, but is not the last in a compound flag string
        } else if ( j < length(these.flags) & spec[rowmatch,col.has.argument] == flag.required.argument ) {
          stop(paste('short flag "', this.flag, '" requires an argument, but has none', sep=''));

        #short flag has no argument, flag it as present
        } else if ( spec[rowmatch,col.has.argument] == flag.no.argument ) {
          result[spec[rowmatch, col.long.name]] = TRUE;
	  done = TRUE;

        #can't definitively process this flag yet, need to see if next option is an argument or not
        } else {
          result[spec[rowmatch, col.long.name]] = TRUE;
          current.flag = rowmatch;
          done = FALSE;
        }
      }
      if ( done ) {
        i = i + 1;
        next;
      }
    }

    #invalid opt
    if ( current.flag == 0 ) {
      stop(paste('"', optstring, '" is not a valid option, or does not support an argument', sep=''));
      #TBD support for positional args
      #if ( debug ) print(paste('"', optstring, '" not a valid option.  It is appended to getopt(...)$ARGS', sep=''));
      #result$ARGS = append(result$ARGS, optstring);

    # some dangling flag, handle it
    } else if ( current.flag > 0 ) {
      if ( debug ) print('    dangling flag');
      if ( length(opt) > i ) {
        peek.optstring = opt[i + 1];
        if ( debug ) print(paste('      peeking ahead at: "',peek.optstring,'"',sep=''));

        #got an argument.  attach it, increment the index, and move on to the next option.  we don't allow arguments beginning with '-' UNLESS
	#specfile indicates the value is an "integer" or "double", in which case we allow a leading dash (and verify trailing digits/decimals).
        if ( substr(peek.optstring, 1, 1) != '-' |
	  #match negative double
	  ( substr(peek.optstring, 1, 1) == '-'
	  & regexpr('^-[0123456789]*\\.?[0123456789]+$',peek.optstring) > 0
	  & spec[current.flag, col.mode]== 'double'
	  ) |
	  #match negative integer
	  ( substr(peek.optstring, 1, 1) == '-'
	  & regexpr('^-[0123456789]+$',peek.optstring) > 0
	  & spec[current.flag, col.mode]== 'integer'
	  )
	) {
          if ( debug ) print(paste('        consuming argument *',peek.optstring,'*',sep=''));

          storage.mode(peek.optstring) = spec[current.flag, col.mode];
          result[spec[current.flag, col.long.name]] = peek.optstring;
          i = i + 1;

	#a lone dash
	} else if ( substr(peek.optstring, 1, 1) == '-' & length(strsplit(peek.optstring,'')[[1]]) == 1 ) {
          if ( debug ) print('        consuming "lone dash" argument');
          storage.mode(peek.optstring) = spec[current.flag, col.mode];
          result[spec[current.flag, col.long.name]] = peek.optstring;
          i = i + 1;

        #no argument
        } else {
          if ( debug ) print('        no argument!');

          #if we require an argument, bail out
          if ( spec[current.flag, col.has.argument] == flag.required.argument ) {
            stop(paste('flag "', this.flag, '" requires an argument', sep=''));

          #otherwise set flag as present.
          } else if (
	    spec[current.flag, col.has.argument] == flag.optional.argument |
	    spec[current.flag, col.has.argument] == flag.no.argument 
	  ) {
  	    x = TRUE;
  	    storage.mode(x) = spec[current.flag, col.mode];
            result[spec[current.flag, col.long.name]] = x;
          } else {
            stop(paste("This should never happen.",
              "Is your spec argument correct?  Maybe you forgot to set",
              "ncol=4, byrow=TRUE in your matrix call?"));
	  }
        }
      #trailing flag without required argument
      } else if ( spec[current.flag, col.has.argument] == flag.required.argument ) {
        stop(paste('flag "', this.flag, '" requires an argument', sep=''));

      #trailing flag without optional argument
      } else if ( spec[current.flag, col.has.argument] == flag.optional.argument ) {
        x = TRUE;
        storage.mode(x) = spec[current.flag, col.mode];
        result[spec[current.flag, col.long.name]] = x;

      #trailing flag without argument
      } else if ( spec[current.flag, col.has.argument] == flag.no.argument ) {
        x = TRUE;
        storage.mode(x) = spec[current.flag, col.mode];
        result[spec[current.flag, col.long.name]] = x;
      } else {
        stop("this should never happen (2).  please inform the author.");
      }
    #no dangling flag, nothing to do.
    } else {
    }

    i = i+1;
  }
  return(result);
}

# convert multi parameter string (i.e. key1: value, key2: value, ...) to object
split <- function(argument){
    # process parameter string
    options <- list()
    list <- gsub("\\s","", argument)
    list <- strsplit(list, ",")
    if (length(list) > 0) {
        list <- list[[1]]
        for (entry in list) {
            pair <- strsplit(entry, ":")
            if (length(pair) > 0) {
                pair <- pair[[1]]
                if (length(pair) == 2) {
                    options[[pair[1]]] <- pair[2]
                }
            }
        }
    }
    return(options)
}

# get options, using the spec as defined by the enclosed list.
spec = matrix(c(
    'workdir',  'w', 1, 'character', 'Work directory',
    'module',   'm', 1, 'character', 'Module name',
    'input',    'i', 1, 'character', 'Input tabular file',
    'columns',  'c', 1, 'character', 'Columns string',
    'settings', 's', 1, 'character', 'Settings string',
    'output',   'o', 1, 'character', 'Output tabular file',
    'help',     'h', 0, '',          'Help',
    'verbose',  'v', 0, '',          'Verbose'
), byrow=TRUE, ncol=5);
opt = getopt(spec);

# show help
if ( !is.null(opt$help) ||
    is.null(opt$module) ||
    is.null(opt$input) ||
    is.null(opt$columns) ||
    is.null(opt$output)) {
    cat(getopt(spec, usage=TRUE))
    q(status=1);
}

# read columns/settings
columns = split(opt$columns)
settings = split(opt$settings)

# read table
table <- read.table(opt$input)

# identify module file
module_file = paste(opt$workdir, opt$module, '.r', sep='')

# source module
source(module_file)

# run module
l = wrapper (table, columns, settings)

# header
header_title <- '# title\t\tCharts Toolkit (chartskit)'
header_date <- paste('# date\t\t', Sys.time(), sep='')
header_module <- paste('# module\t', opt$module, sep='')
header_settings <- paste('# settings\t', opt$settings, sep='')
header_columns <- paste('# columns\t', opt$columns, sep='')

# fill gaps
if (length(l) > 0) {
    # print details
    if (!is.null(opt$verbose)) {
        print ('Columns:')
        print (columns)
        print ('Settings:')
        print (settings)
        print ('Result:')
        print (l)
    }

    # create output file
    output <- file(opt$output, open='wt')
    
    # write header
    writeLines('#', output)
    writeLines(header_title, output)
    writeLines(header_date, output)
    writeLines(header_module, output)
    writeLines(header_settings, output)
    writeLines(header_columns, output)
    writeLines('#', output)
    
    # write table
    write.table(l, file=output, row.names=FALSE, col.names = FALSE, quote=FALSE, sep='\t')
    
    # close file
    close(output)
} else {
    print ('Columns:')
    print (columns)
    print ('Settings:')
    print (settings)
    print ('No output generated.')
}