#!/bin/bash

BASE="/usr/share/sicp/"

cd ${BASE}

doload="yay";

if [ -z "${1}" ]; then
	echo "please tell me what to load."
	echo
	echo "syntax: sicp <chapter> [<part>]"
	echo ""
	echo " chapter: which sources to load, sorted by sicp chapter (1-5)"
	echo " part: for chapters 4 and 5, the code is split into smaller parts"
	echo " (to find out what parts are fine to load, simply run 'sicp 4' or 'sicp 5')"

	exit 1
fi;

if [ "${1}" = "3" ]; then
	echo "SICP advises against loading this whole file."
	echo "Instead, you should capy & paste the parts you need."

        file="${BASE}/ch3support.scm ${BASE}/ch${1}.scm"
elif [ "${1}" = "4" ]; then
	if [ -z "${2}" ]; then
		doload="nay"
		echo "The SICP sources say that you should rather load specific parts of the code for Chapter 4."
		echo "Possible parts are:"
		echo " * ambeval"
		echo " * leval"
		echo " * mceval"
		echo " * query"
		echo " * analyzingmceval"
		echo "Parts that depend on other parts will automatically load these."
	else
		file="${BASE}/ch${1}-${2}.scm"
		echo "Reminder: use"
		echo "(define the-global-environment (setup-environment))"
		echo "to set things up, and"
		echo "(driver-loop)"
		echo "to start the interpreter"
	fi;
elif [ "${1}" = "5" ]; then
	if [ -z "${2}" ]; then
		doload="nay"
		echo "The SICP sources say that you should rather load specific parts of the code for Chapter 4."
		echo "Possible parts are:"
		echo " * compiler"
		echo " * eceval-compiler"
		echo " * eceval"
		echo " * regsim"
		echo "Parts that depend on other parts will automatically load these."
	else
		if [ "${2}" = "eceval-compiler" ]; then
			file="${BASE}/ch5-regsim.scm ${BASE}/ch5-eceval-support.scm ${BASE}/ch5-eceval-compiler.scm"
			echo ";; To start, you can use compile-and-go as in section 5.5.7"
			echo ";;  or start-eceval as in the section 5.5.7 footnote."
			echo ""
			echo ";; To resume the machine without reinitializing the global environment"
			echo ";; if you have somehow interrupted out of the machine back to Scheme, do"
			echo ""
			echo ";: (set-register-contents! eceval 'flag false)"
			echo ";: (start eceval)"
		elif [ "${2}" = "eceval" ]; then
			file="${BASE}/ch5-regsim.scm ${BASE}/ch5-eceval-support.scm ${BASE}/ch5-eceval.scm"
			echo ";;; -- To initialize and start the machine, do"
			echo ""
			echo ";: (define the-global-environment (setup-environment))"
			echo ""
			echo ";: (start eceval)"
			echo ""
			echo ";; To restart, can do just"
			echo ";: (start eceval)"
		else
			file="${BASE}/ch${1}-${2}.scm"
		fi
	fi;
else
	file="${BASE}/ch${1}.scm"
fi;

if [ "${doload}" = "yay" ]; then
	echo "SICP sources are loaded into the mzscheme interpreter. Use (exit) to quit."
	mzscheme --Load "${BASE}/helper.scm" ${file}
fi;