#!/bin/bash
set -euo pipefail
# TODO: check with dash to confirm that it is working!
# TODO: check dependencies like 7z/unzip/cabextract and generalize
# TODO: deal with case-insenstivity on input!
export LC_ALL=C

script_name="$(basename $0)"
cd_path=''
fdimg_path=''
cd_drv=''

msg_help () {
  echo "Usage: $script_name -i <cd_path> -o <floppy_image> [-c <cd_driver>] [-m <memory_manager_driver>]"
  echo "<cd_path> needs to point to root of extracted/mounted ISO/CD"
}

msg_err () {
  echo "Error: $@" >&2
}

7z_e () {
  # Extract single file to empty dir, to aid with uppercase rename
  # $1 - path to archive, starting from CD root
  # $2 - path inside archive
  # $3 - path inside floppy (only if renaming)
  # For now assuming no subdirs in archives
  # TODO: auto-rename to uppercase if only 2 arguments!
  # TODO: automatically match case of file inside archive!
  # TODO: check if 7z actually extracted file
  if [ $# -gt 3 ] || [ $# -lt 2 ]; then
    msg_err "7z_e(): Invalid number of arguments"
    exit 1
  fi
  # Make sure extract dir is empty
  extracted_cnt=$(ls -1 "$FDDIR/extract/" | wc -l)
  if [ "$extracted_cnt" != "0" ]; then
    msg_err "Unexpected $FDDIR/extract/ contents"
    exit 1
  fi
  7z -ssc- e "$cd_path/$1" "$2" -o"$FDDIR/extract/" > /dev/null
  # 7z doesn't seem to produce exit code on failure
  extracted_file=$(ls -1 "$FDDIR/extract/")
  if [ -z "$extracted_file" ] || [ ! -s "$FDDIR/extract/$extracted_file" ]; then
    msg_err "Failed to extract $2 from $1"
    exit 1
  fi
  if [ $# -eq 3 ]; then
    mv "$FDDIR/extract/$extracted_file" "$FDDIR/$3"
  else
    extracted_upper=$(ls -1 "$FDDIR/extract/" | tr '[a-z]' '[A-Z]')
    mv "$FDDIR/extract/$extracted_file" "$FDDIR/$extracted_upper"
  fi
}

while getopts 'i:o:c:m:' copt
do case $copt in
  i) cd_path="$OPTARG" ;;
  o) fdimg_path="$OPTARG" ;;
  c) cd_drv="$OPTARG" ;;
  ?) msg_help ;;
esac done

if [ -z "$cd_path" ] || [ -z "$fdimg_path" ]; then
  msg_err 'Missing path to cd or floppy image'
  msg_help
  exit 1
fi

if [ ! -d "$cd_path" ]; then
  msg_err "Mounted/extracted CD/ISO directory $cd_path does not exist"
  msg_help
  exit 1
fi

if [ ! -f "$cd_path/admin/nettools/fac/ltools.dta" ]; then
  msg_err "$cd_path does not contain windows 95 files or it's missing OPK portion"
  msg_help
  exit 1
fi

if [ -e "$fdimg_path" ]; then
  msg_err "$fdimg_path already exists!"
  exit 1
fi

# TODO: fdimg_path dir check

FDDIR=$(mktemp -d)
if [ $? != 0 ] || [ -z "$FDDIR" ] || [ ! -d "$FDDIR" ] || [ ! -w "$FDDIR" ]; then
  msg_err "failure to create tmpdir $FDDIR"
  exit 1
fi
mkdir -p "$FDDIR/extract"
echo "TMPDIR: $FDDIR"

# Extract/rename/prepare files
# Floppy bootsector
# admin/nettools/fac/{tls,pld,ltools}.dta
# TODO: have wrapper for 7z that will save 7z log to 7z.log and output it on errors
7z x "$cd_path/admin/nettools/fac/tls.dta" 'PBF.IMG' -o"$FDDIR" > /dev/null
# Essential files
7z x "$cd_path/admin/nettools/fac/ltools.dta" 'io.sys' -o"$FDDIR" > /dev/null
mv "$FDDIR/io.sys" "$FDDIR/IO.SYS"
#7z x "$cd_path/admin/nettools/fac/ltools.dta" 'MSDOS.SYS' -o "$FDDIR"
#7z x "$cd_path/admin/nettools/fac/pld.dta" 'MSDOS.FAC' -o "$FDDIR"
#mv 'MSDOS.FAC' 'MSDOS.SYS'
cat > "$FDDIR/MSDOS.SYS" << EOF
[OPTIONS]
BOOTGUI=0
LOGO=0
EOF
7z x "$cd_path/admin/nettools/fac/ltools.dta" 'command.com' -o"$FDDIR" > /dev/null
mv "$FDDIR/command.com" "$FDDIR/COMMAND.COM"
# Memory manager - TODO: conditional
7z x "$cd_path/admin/nettools/fac/ltools.dta" 'HIMEM.SYS' -o"$FDDIR" > /dev/null
# CONFIG.SYS - TODO: conditional - also concatenate several things:
# MCD if HIMEM
# Add extra CD driver line if including CD driver
# CD driver
# Probably creates too much hardcode:
# SHELL=A:\COMMAND.COM A:\ /P
# Can we have relative path instead?
cat > "$FDDIR/CONFIG.SYS" << EOF
DEVICE=HIMEM.SYS /TESTMEM:OFF
BUFFERS=20
FILES=60
LASTDRIVE=Z
DOS=HIGH,UMB

SHELL=A:\COMMAND.COM A:\ /P

DEVICE=CDROM.SYS /D:MSCD000
EOF
# TODO
# MSCDEX.EXE
7z x "$cd_path/admin/nettools/fac/tls.dta" 'MSCDEX.EXE' -o"$FDDIR" > /dev/null
# CD driver - for now OAK
7z x "$cd_path/drivers/modem/wdlboca1/drivers.zip" 'ATAPI_CD.SYS' -o"$FDDIR" > /dev/null
mv "$FDDIR/ATAPI_CD.SYS" "$FDDIR/CDROM.SYS"
# Autoexec for MSCDEX.EXE - based on AUTOEXEC.FAC TODO
echo '@ECHO OFF' > "$FDDIR/AUTOEXEC.BAT"
echo 'SET PATH=A:' >> "$FDDIR/AUTOEXEC.BAT"
echo -ne 'LH MSCDEX.EXE /D:MSCD000 /L:Z' >> "$FDDIR/AUTOEXEC.BAT"
# TOOLS
7z x "$cd_path/admin/nettools/fac/tls.dta" 'OXCOPY.EXE' -o"$FDDIR" > /dev/null
mv "$FDDIR/OXCOPY.EXE" "$FDDIR/XCOPY.EXE"
7z x "$cd_path/admin/nettools/fac/pld.dta" 'OFORMAT.COM' -o"$FDDIR" > /dev/null
mv "$FDDIR/OFORMAT.COM" "$FDDIR/FORMAT.COM"
7z x "$cd_path/admin/nettools/fac/pld.dta" 'ofdisk.exe' -o"$FDDIR" > /dev/null
mv "$FDDIR/ofdisk.exe" "$FDDIR/FDISK.EXE"
7z x "$cd_path/admin/nettools/fac/ltools.dta" 'SYS.COM' -o"$FDDIR" > /dev/null
7z x "$cd_path/admin/nettools/fac/pld.dta" 'REBOOT.EXE' -o"$FDDIR" > /dev/null
7z x "$cd_path/admin/nettools/fac/cbs.dta" 'ATTRIB.EXE' -o"$FDDIR" > /dev/null
7z x "$cd_path/admin/nettools/fac/cbs.dta" 'EDIT.COM' -o"$FDDIR" > /dev/null
cp "$cd_path/win95/scandisk.exe" "$FDDIR/SCANDISK.EXE"

# Convert text files to dos newlines
unix2dos -q "$FDDIR/MSDOS.SYS"
unix2dos -q "$FDDIR/CONFIG.SYS"
unix2dos -q "$FDDIR/AUTOEXEC.BAT"

# Final floppy creation
mkfs.msdos -C "$fdimg_path" 1440
dd if="$FDDIR/PBF.IMG" of="$fdimg_path" conv=notrunc status=none
mcopy -i "$fdimg_path" "$FDDIR/IO.SYS" ::
mcopy -i "$fdimg_path" "$FDDIR/MSDOS.SYS" ::
mcopy -i "$fdimg_path" "$FDDIR/CONFIG.SYS" ::
mcopy -i "$fdimg_path" "$FDDIR/HIMEM.SYS" ::
mcopy -i "$fdimg_path" "$FDDIR/CDROM.SYS" ::
mcopy -i "$fdimg_path" "$FDDIR/"*.COM ::
mcopy -i "$fdimg_path" "$FDDIR/"*.EXE ::
mcopy -i "$fdimg_path" "$FDDIR/"*.BAT ::

# TODO: This does not fix OEMID
mlabel -i test.img ::WIN_BOOT -n

# TODO: cleanup
#rm -vrd "$FDDIR"
echo "Removed $FDDIR"