#!/bin/sh
# converts kasi.sh key-value pairs to kasi.el sexps

# kasi.sh format
# password_on_first_line
# Username: someone
# Email: bob@example.org
# TOTP: some_base32_string
# anything else can go here too

# kasi.el format
# -*- mode: lisp -*-
# ((password "password_here")
#  (username "someone")
#  (email "bob@example.org")
#  (totp "some_base32_string")
#  (extra-content "\
#    anything not matched
#    goes in here")
#
# if any of the fields are not parsed/found in original, it will be
# set to nil in sexp

KASI_DIR="/data/kasi"
KASI_EXT=".age"
KASI_DECRYPT="age -d -i $HOME/.ssh/id_ed25519"
KASI_ENCRYPT="age -R $HOME/.ssh/id_ed25519.pub"

lisp_val() {
    if [ -z "$1" ]; then
        printf 'nil'
    else
        printf '"%s"' "$(printf '%s' "$1" | sed 's/\\/\\\\/g; s/"/\\"/g')"
    fi
}

convert() {
    f="${KASI_DIR}/${1}${KASI_EXT}"
    contents="$($KASI_DECRYPT "$f")" || {
        printf 'error: failed to decrypt %s\n' "$f" >&2
        return 1
    }

    first_line=$(printf '%s\n' "$contents" | sed -n '1p')
    second_line=$(printf '%s\n' "$contents" | sed -n '2p')
    last_char=$(printf '%s' "$contents" | tail -c 1)
    if [ "$first_line" = "; -*- mode: lisp -*-" ] && [ "${second_line#((}" != "$second_line" ] && [ "$last_char" = ")" ]; then
        printf 'skipping %s (already converted)\n' "$1" >&2
        return 0
    fi

    password=$(printf '%s\n' "$contents" | sed -n '1p')
    username=$(printf '%s\n' "$contents" | sed -n 's/^Username:[[:space:]]*//p' | sed 's/[[:space:]]*$//' | head -1)
    email=$(printf '%s\n'    "$contents" | sed -n 's/^Email:[[:space:]]*//p'    | sed 's/[[:space:]]*$//' | head -1)
    totp=$(printf '%s\n'     "$contents" | sed -n 's/^TOTP:[[:space:]]*//p'     | sed 's/[[:space:]]*$//' | head -1)

    extra=$(printf '%s\n' "$contents" | awk 'NR > 1 && !/^(Username|Email|TOTP):/ && NF')

    printf '; -*- mode: lisp -*-\n'
    printf '((password %s)\n'  "$(lisp_val "$password")"
    printf ' (username %s)\n'  "$(lisp_val "$username")"
    printf ' (email %s)\n'     "$(lisp_val "$email")"
    printf ' (totp %s)\n'      "$(lisp_val "$totp")"

    if [ -z "$extra" ]; then
        printf ' (extra-content nil))\n'
    else
        esc=$(printf '%s' "$extra" | sed 's/\\/\\\\/g; s/"/\\"/g')
        printf ' (extra-content "\\\n%s"))\n' "$esc"
    fi
}

cd "$KASI_DIR"
for i in */*"$KASI_EXT"; do
    i="${i%%$KASI_EXT}"
    j="$(mktemp)"
    convert "$i" > "$j"
    $KASI_ENCRYPT <"$j" >"$i""$KASI_EXT"
    rm "$j"
done