hori

#!/bin/sh
# shellcheck shell=dash disable=SC1090

yell() { echo "hori: $*" 1>&2 ; }

# -- templates

# replace $2 with $3 in string $1
replace() { echo "${1%%"$2"*}${3}${1#*"$2"}" ; }

# extract shortest substring from string $1 between $2 and $3
extract() { local s=${1%%"$3"*} ; echo "${s##*"$2"}" ; }

import() { # recursively import config into pathed variables
  local varset=$1 prefix=$2
  [ "$varset" = "conf" ] || prefix=${prefix}_${1##*\/}
  prefix="$(echo "$prefix" | sed 's/\//_/g')" # FIXME get rid of sed maybe
  while read -r line ; do
    if [ "${line#"import "}" != "$line" ]; then
      import "${line#"import "}" "$prefix"
    elif [ "${line#[[:alnum:]]*"="}" != "$line" ]; then # nb: only alnum in assignments
      eval "_${prefix}_${line}"
    fi
  done < "$REPO/hori/$varset"
}

template() { # render <1:file> with the current context
  local expr old_expr key val
  while IFS= read -r line; do
    while [ "${line#*"{% "[!" "]*" %}"*}" != "$line" ]; do
      expr="$(extract "$line" "{% " " %}")"
      old_expr=$expr
        while [ "${expr#*"{"[!\{\}]*"}"*}" != "$expr" ]; do
          key="$(extract "$expr" "{" "}")"
          val="$(eval "echo \$__$key")"
          [ -z "$val" ] && { yell "'$key' is undefined, aborting" ; exit 1 ; }
          expr="$(replace "$expr" "{$key}" "$val")"
        done
      line="$(replace "$line" "{% $old_expr %}" "$expr")"
    done
    echo "$line"
  done < "$1"
}

# -- actions

launch() { # kill existing <1:process> and run <@:command>
  pkill -x "$1" ; sleep 0.2 ; "$@"
}

render() { # render <1:file(rel)> and return its path
  local source=$REPO/$PACK/$1
  local target=$HORI/$PACK/$1
  mkdir -p "${target%/*}"
  template "$source" > "$target"
  echo "$target"
}

link() { # create symlink from <1:source(rel)> to <2:target(abs)>
  local source target=$2
  [ "${1#*"$HORI"*}" != "$1" ] && source=$1 || source=$REPO/$PACK/$1
  mkdir -p "${target%/*}"
  ln -sfn "$source" "$target"
}

unlink() { # remove <1:symlink(abs)>
  [ -h "$1" ] && rm "$1"
}

# -- hook

list() {
  case $* in
    -i|--installed) packages="$HORI/*" ;;
    -a|--available) packages="$REPO/*" ;;
    *) packages="$*" ;;
  esac
  for p in $packages; do
    p="${p##*/}"
    if [ -f "$REPO/$p/hori.sh" ]; then
      echo "$p"
    # else
      # TODO why is this here and not in hook?
      # yell "{$p} is not a valid package"
    fi
  done
}

edit() {
  local c
  c="$(for p in $(list -a); do
    find "$REPO/$p/" | while read -r line; do
      echo "${line##*"$REPO/"}"
    done
  done | fzf)"
  if [ -n "$c" ]; then
    if [ -f "$HORI/$c" ]; then
      echo "$REPO/$c" | entr -np hori add "${c%%/*}" &
      pid=$!
    fi
    $EDITOR "$REPO/$c"
    if [ -n "$pid" ]; then kill "$pid"; else exit 0; fi
  fi
}

hook() { # execute <1:hook> in <@:packages>
  local h=$1 ; shift
  list "$@" | while read -r p; do
    PACK=$p ; (
      . "$REPO/$p/hori.sh"
      if type "$h" >/dev/null 2>&1; then
        case $h in
          add) mkdir -p "$HORI/$p" ;;
        esac
        yell "<$h> in {$p}"
        "$h"
        case $h in
          del) [ -d "${HORI:?}/$p" ] && rm -r "${HORI:?}/$p" ;;
        esac
      else
        yell "no <$h> hook in {$p} package"
      fi
    ) ; unset PACK
  done
}

# -- main

HORI="$HOME/.config/hori"
REPO="$(cat "$HORI/.repo" 2>/dev/null || dirname "$(find ~ -type f -name "repository.hori" -print -quit 2>/dev/null)")"

if [ -f "$REPO/repository.hori" ]; then
  mkdir -p "$HORI"
  echo "$REPO" > "$HORI/.repo"
else
  yell "could not find repo, aborting" ; exit 1
fi

import conf

cmd=$1 ; shift
case $cmd in
  -h|--help|"") echo "\$ hori <hook> (<package(s)>|-i|-a)\n  from $REPO" ;;
  l|list) list "$@" ;;
  e|edit) edit "$@" ;;
  *) hook "$cmd" "$@" ;;
esac