#!/bin/sh

# Copyright (C) 2021 Wojtek Kosior
# Redistribution terms are gathered in the `copyright' file.

ENDL="
"

errcho() {
    echo "$@" >&2
}

map_set_instr() {
    echo "$1__$2='$3'"
}

map_set() {
    eval "$(map_set_instr "$@")"
}

map_get() {
    eval "echo \"\$$1__$2\""
}

map_del_instr() {
    echo "unset $1__$2"
}

map_del() {
    eval "$(map_del_instr "$@")"
}

sanitize() {
    echo "$1" | tr /.- _
}

handle_export_line() {
    if [ "x$1" = "xEXPORTS_START" ]; then
	if [ "$STATE" = "before_block" ]; then
	    STATE="in_block"
	fi
    elif [ "x$1" = "xEXPORT" ]; then
	if [ "$STATE" != "in_block" ]; then
	    return
	fi

	EXPORTCODE="${EXPORTCODE}window.killtheweb.$2 = $2;$ENDL"

	PREVIOUS_FILE="$(map_get EXPORTS $2)"
	if [ "x$PREVIOUS_FILE" != "x" ]; then
	    errcho "export $2 present in both $PREVIOUS_FILE and $FILE"
	    return 1
	fi

	map_set_instr EXPORTS $2 "$FILE"

    elif [ "x$1" = "xEXPORTS_END" ]; then
	if [ "$STATE" = "in_block" ]; then
	    STATE="after_block"
	fi
    fi
}

translate_exports() {
    STATE="before_block"
    EXPORTCODE=''

    while read EXPORT_LINE; do
	handle_export_line $EXPORT_LINE || return 1
    done

    map_set_instr EXPORTCODES $FILEKEY "$EXPORTCODE"
}

add_exports() {
    FILE="$1"
    FILEKEY="$(sanitize "$FILE")"

    eval "$(grep -o 'EXPORT.\+' "$1" | translate_exports || exit 1)"
}

handle_import_line() {
    if [ "x$1" = "xIMPORTS_START" ]; then
	if [ "$STATE" = "before_block" ]; then
	    STATE="in_block"
	fi
    elif [ "x$1" = "xIMPORT" ]; then
	if [ "$STATE" != "in_block" ]; then
	    return
	fi

	IMPORTCODE="${IMPORTCODE}const $2 = window.killtheweb.$2;$ENDL"

	IMPORTS="$IMPORTS $2"

    elif [ "x$1" = "xIMPORTS_END" ]; then
	if [ "$STATE" = "in_block" ]; then
	    STATE="after_block"
	fi
    fi
}

translate_imports() {
    STATE="before_block"
    IMPORTCODE=''
    IMPORTS=''

    while read IMPORT_LINE; do
	handle_import_line $IMPORT_LINE || return 1
    done

    map_set_instr IMPORTCODES $FILEKEY "$IMPORTCODE"
    map_set_instr IMPORTS $FILEKEY "$IMPORTS"
}

add_imports() {
    FILE="$1"
    FILEKEY="$(sanitize "$FILE")"

    eval "$(grep -o 'IMPORT.\+' "$1" | translate_imports || exit 1)"
}

compute_scripts_list_rec() {
    local FILE="$1"
    local FILEKEY=$(sanitize "$1")

    local FILESTATE="$(map_get FILESTATES $FILEKEY)"
    if [ "xprocessed" = "x$FILESTATE" ]; then
	return
    fi
    if [ "xprocessing" = "x$FILESTATE" ]; then
	errcho "import loop on $FILE"
	return 1
    fi

    USED="$USED $FILEKEY"

    map_set FILESTATES $FILEKEY "processing"

    local IMPORT
    for IMPORT in $(map_get IMPORTS $FILEKEY); do
	NEXT_FILE="$(map_get EXPORTS $IMPORT)"
	if [ "x" = "x$NEXT_FILE" ]; then
	    errcho "nothing exports $IMPORT, required by $FILE"
	    return 1
	fi
	if ! compute_scripts_list_rec "$NEXT_FILE"; then
	    errcho "when satisfying $IMPORT for $FILE"
	    return 1
	fi
    done

    echo $FILE
    map_set FILESTATES $FILEKEY "processed"
}

compute_scripts_list() {
    USED=''
    echo COMPUTED_SCRIPTS=\"exports_init.js
    compute_scripts_list_rec "$1"
    echo \"

    for FILEKEY in $USED; do
	map_set_instr USED $FILEKEY yes
    done
}

as_json_list() {
    while true; do
	if [ "x" = "x$2" ]; then
	    echo -n '\\n'"\t\t\"$1\""'\\n\t'
	    return
	fi
	echo -n '\\n'"\t\t\"$1\","
	shift
    done
}

as_html_list() {
    while [ "x" != "x$1" ]; do
	echo -n '\\n'"    <script src=\"/$1\"></script>"
	shift
    done
}

set_browser() {
    if [ "x$1" = "xmozilla" -o "x$1" = "xchromium" ]; then
	BROWSER="$1"
    else
	errcho "usage:  $0 mozilla|chromium"
	exit 1
    fi
}

main() {
    set_browser "$1"

    SCRIPTDIRS='background html common content'

    SCRIPTS=$(find $SCRIPTDIRS -name '[^.#]*.js')

    for SCRIPT in $SCRIPTS; do
	add_exports $SCRIPT
	add_imports $SCRIPT
    done

    eval "$(compute_scripts_list background/main.js || exit 1)"
    BGSCRIPTS="$(as_json_list $COMPUTED_SCRIPTS)"
    eval "$(compute_scripts_list content/main.js || exit 1)"
    CONTENTSCRIPTS="$(as_json_list $COMPUTED_SCRIPTS)"
    eval "$(compute_scripts_list html/display-panel.js || exit 1)"
    POPUPSCRIPTS="$(as_html_list $COMPUTED_SCRIPTS)"
    eval "$(compute_scripts_list html/options_main.js || exit 1)"
    OPTIONSSCRIPTS="$(as_html_list $COMPUTED_SCRIPTS)"

    BUILDDIR=build_$BROWSER
    rm -rf $BUILDDIR
    mkdir $BUILDDIR
    for DIR in $(find $SCRIPTDIRS -type d); do
	mkdir -p $BUILDDIR/$DIR
    done

    CHROMIUM_KEY=''
    GECKO_APPLICATIONS=''

    if [ "$BROWSER" = "chromium" ]; then
	CHROMIUM_KEY="\n\
\n\
    // WARNING!!!\n\
    // EACH USER SHOULD REPLACE \"key\" WITH A UNIQUE VALUE!!!\n\
    // OTHERWISE, SECURITY CAN BE TRIVIALLY COMPROMISED!\n\
    //\n\
    // A unique key can be generated with:\n\
    // $ ssh-keygen -f /path/to/new/key.pem -t rsa -b 1024\n\
    //\n\
    // Only relevant to users of chrome-based browsers.\n\
    // Users of Firefox forks are safe.\n\
\n\
    \"key\": \"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\","
    else
	GECKO_APPLICATIONS="\n\
    \"applications\": {\n\
	\"gecko\": {\n\
	    \"id\": \"{6fe13369-88e9-440f-b837-5012fb3bedec}\",\n\
	    \"strict_min_version\": \"60.0\"\n\
	}\n\
    },"
    fi

    sed "\
s^_GECKO_APPLICATIONS_^$GECKO_APPLICATIONS^
s^_CHROMIUM_KEY_^$CHROMIUM_KEY^
s^_BGSCRIPTS_^$BGSCRIPTS^
s^_CONTENTSCRIPTS_^$CONTENTSCRIPTS^" \
	< manifest.json > $BUILDDIR/manifest.json

    sed "s^_POPUPSCRIPTS_^$POPUPSCRIPTS^" \
	< html/display-panel.html > $BUILDDIR/html/display-panel.html

    sed "s^_OPTIONSSCRIPTS_^$OPTIONSSCRIPTS^" \
	< html/options.html > $BUILDDIR/html/options.html

    for FILE in $SCRIPTS; do
	FILEKEY=$(sanitize "$FILE")
	if [ "xyes" != "x$(map_get USED $FILEKEY)" ]; then
	    errcho "WARNING! $FILE not used"
	else
	    (echo "\
\"use strict\";

(() => {
$(map_get IMPORTCODES $FILEKEY)

";

# A hack to insert the contents of default_settings.json at the appropriate location in background/main.js
if [ "$FILE" = "background/main.js" ]; then
    # Uses an internal sed expression to escape and indent the JSON file for use in the external sed expression
    sed 's/^        `DEFAULT SETTINGS`$/'"$(sed -E 's/([\\\&\/])/\\\1/g; s/^/        /; s/$/\\/' < default_settings.json) "/g < "$FILE"
else
    cat $FILE
fi

echo "

$(map_get EXPORTCODES $FILEKEY)
})();") > $BUILDDIR/$FILE
	fi
    done

    echo "\
window.killtheweb={};
window.browser = this.browser; /* fix for stupid Firefox */
" > $BUILDDIR/exports_init.js

    cp -r icons/ copyright licenses/ $BUILDDIR
}

main "$@"