#!/bin/sh

set -e

argv0="$0"
argv1="$1"
argv2="$2"

# check usage
if ! test -n "$1"; then
  printf "Usage: %s [OPTIONS] [TABLE.KEY[INDEX]] [FILE]\n" "$0" 1>&2
  exit 64 # sysexits(3) EX_USAGE
fi

# test if input has a period
if test -n "$(printf "%s\n" "$argv1" | sed -n '/.*\..*/p')"; then
  # cut out everything beyond the first period for TABLE
  TABLE=$(printf "%s\n" "$argv1" | sed -n 's/\..*//p')

  # cut out everything before the first period for KEY
  KEY=$(printf "%s\n" "$argv1" | sed -n 's/^[^.]*\.//p')
  ! test -n "$KEY" &&\
    printf "%s: No key specified\n" "$argv0" 1>&2 &&\
    exit 65 # sysexits(3) EX_DATAERR
else
  printf "%s: No key specified\n" "$argv0" 1>&2
  exit 65 # sysexits(3) EX_DATAERR
fi

# remove array index from KEY
KEY=$(printf "%s\n" "$KEY" | sed 's/\[.*\]//g')
# set ARR to the array index
ARR=$(printf "%s\n" "$argv1" | sed -n 's/.\+\[//p' | tr -d ']')

# test if argument 2 is a file or not
if test -e "$argv2"; then
  # set TOML to the text from the file
  TOML=$(sed 's/[^"#]#\+.*//g' <"$argv2" | sed 's/^#.*//g' )
else
  # set TOML to the text from stdin
  TOML=$(printf "%s\n" "$argv2" | sed 's/[^"#]#\+.*//g')
fi

if test -n "$TABLE"; then
  KEYS=$(printf "%s\n" "$TOML" |\
        # output only lines between TABLE and the next table
          awk "/^\[$TABLE\]/{flag=1; next} /^\[/{flag=0} flag" - )
else
  KEYS=$(printf "%s\n" "$TOML" |\
        # output only lines before the first table
          awk '1;/^\[/{exit}' - | sed -n '/^[^[]/p')
fi

# set VAL to the parsed KEYS list
VAL=$(printf "%s\n" "$KEYS" |\
        # remove the key from the string and delineate arrays, removing
        # brackets, trailing commas, and leading spaces
        sed -n "s/$KEY *= *//p" | sed 's/", "/	/g' | tr -d '[]"' |\
        sed 's/, *$//g' | sed 's/^ \+//g' | sed 's/ \+$//g')

# test if ARR is set; if it is, then we have an array index to grab
if test -n "$ARR"; then
  # change the line delineator to newlines for parsing and output the result
  printf "%s\n" "$VAL" | sed 's/	/\n/g' | head -n "$ARR" |\
    tail -n 1
elif !  test -n "$VAL"; then
  printf "%s: %s: No such key or table\n" "$argv0" "$argv1" 1>&2
  exit 65 # sysexits(3) EX_DATAERR
else
  printf "%s\n" "$VAL"
fi

exit 0