#!/bin/sh

# Regenerate the *-theme.auto.conf files kitty reads at startup from the
# canonical themes in ./themes, honouring the mode recorded in ./theme-mode:
#
#   auto   every appearance keeps its own theme, so kitty follows the OS
#   light  every appearance gets the light theme, so kitty stays light
#   dark   every appearance gets the dark theme, so kitty stays dark
#
# kitty gives the automatic theme files priority over everything else -- includes
# and even --override -- so pinning a mode means writing the wanted theme into
# whichever file the OS makes kitty pick. That is why the real themes live in
# ./themes and these three files are generated.

set -eu

# Permission bits of a file, or 600 if they cannot be read. GNU stat spells this
# `-c %a` while BSD/macOS spells it `-f %Lp`, and each mis-parses the other's
# form -- GNU treats `-f` as --file-system and prints a block of filesystem info
# before failing -- so try one at a time and only accept an octal answer.
file_mode() {
    _m=$(stat -c '%a' "$1" 2>/dev/null) || _m=''
    case "$_m" in
        [0-7][0-7][0-7] | [0-7][0-7][0-7][0-7]) printf '%s\n' "$_m"; return 0 ;;
    esac
    _m=$(stat -f '%Lp' "$1" 2>/dev/null) || _m=''
    case "$_m" in
        [0-7][0-7][0-7] | [0-7][0-7][0-7][0-7]) printf '%s\n' "$_m"; return 0 ;;
    esac
    printf '600\n'
}

script_dir="$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)"
config_dir=${1:-"$script_dir"}
canonical_dir="$config_dir/themes"
mode_file="$config_dir/theme-mode"

mode=auto
if [ -f "$mode_file" ]; then
    mode=$(tr -d ' \t\r\n' < "$mode_file")
fi
case "$mode" in
    auto | light | dark) ;;
    *) mode=auto ;;
esac

mkdir -p "$canonical_dir"

# Adopt the current automatic themes as canonical when they have not been
# captured yet. Only safe while following the OS: under a pinned mode the
# generated files all hold the pinned theme and would overwrite the others.
if [ "$mode" = auto ]; then
    for appearance in dark light no-preference; do
        canonical="$canonical_dir/$appearance.conf"
        generated="$config_dir/$appearance-theme.auto.conf"
        if [ ! -f "$canonical" ] && [ -f "$generated" ]; then
            cp "$generated" "$canonical"
        fi
    done
fi

for appearance in dark light no-preference; do
    if [ "$mode" = auto ]; then
        source_name=$appearance
    else
        source_name=$mode
    fi

    canonical="$canonical_dir/$source_name.conf"
    [ -f "$canonical" ] || continue

    generated="$config_dir/$appearance-theme.auto.conf"
    mode_bits=600
    if [ -f "$generated" ]; then
        mode_bits=$(file_mode "$generated")
    fi

    tmp=$(mktemp "$generated.tmp.XXXXXX")
    trap 'rm -f "$tmp"' EXIT HUP INT TERM
    cat "$canonical" > "$tmp"
    chmod "$mode_bits" "$tmp"
    mv -f "$tmp" "$generated"
    trap - EXIT HUP INT TERM
done

"$script_dir/repair-auto-themes.sh" "$config_dir"