feat(common/init): Add a shell script, that populates variables

The line editing can't really shell out to bash, as the default
bash on NixOS is compiled without GNU `readline` support (you need
`bashInterative` for `read -e` to work).

2 files changed, 288 insertions, 0 deletions

diff --git a/common/init b/common/init
new file mode 100755
index 0000000..787b663
--- /dev/null
+++ b/common/init
@@ -0,0 +1,71 @@
+#!/usr/bin/env sh
+
+. "$(realpath "$(dirname "$0")")/shell_line_editor.sh"
+
+replacement_file="$(mktemp)"
+
+trap cleanup INT
+trap "cleanup; remove" EXIT
+cleanup() {
+    rm "$replacement_file"
+}
+remove() {
+    rm "$(realpath "$0")"
+    rm "$(realpath "$(dirname "$0")")/shell_line_editor.sh"
+    git add .
+}
+
+# Prompt the user for a specific variable. The variable is the first
+# input, the second is an optional description.
+# The third argument can be a suggested answer, already pre populated.
+prompt() {
+    pr_variable_upper="$(echo "$1" | sed 's/\([a-z]\)/\U\1/')"
+    pr_description="$2"
+    pr_suggested_answer="$3"
+
+    printf "\033[94;1mEnter %s\033[0m" "$pr_variable_upper"
+    if [ -n "$pr_description" ];then
+        printf " (\033[93;1m%s\033[0m):\n" "$pr_description"
+    else
+        printf ":\n"
+    fi
+
+    # LE "> " 0 " " "$pr_suggested_answer" "yes_please_produce_debug_output"
+    LE "> " 0 " " "$pr_suggested_answer" ""
+
+    pr_new_variable="$(printf '%s="%s"' "$pr_variable_upper" "$REPLY")"
+
+    eval "$pr_new_variable"
+    printf "%s\n" "$pr_new_variable" >> "$replacement_file"
+}
+
+git init
+
+# necessary meta data
+prompt APPLICATION_NAME "The name of the application" "$(basename "$PWD")"
+prompt APPLICATION_NAME_STYLIZED "The stylized name of the application (for documentation)" "$(basename "$PWD" | sed 's/\([a-z]\)/\u\1/')"
+prompt AUTHOR_NAME "The name of the author (or authors)" "$(git config --get user.name)"
+prompt AUTHOR_EMAIL "The email of the author (or authors)" "$(git config --get user.email)"
+
+# cog change-log variables
+prompt REMOTE "The remote, this project will be pushed to" "codeberg.org"
+prompt REPOSITORY "The name of the repository in the remote" "$APPLICATION_NAME"
+prompt OWNER "The name of owner of the repository" "$AUTHOR_NAME"
+
+# nice meta data
+prompt DESCRIPTION "The description of this project" "[can be empty]"
+
+# LICENSE.spdx data (source: https://github.com/david-a-wheeler/spdx-tutorial)
+prompt APPLICATION_ORIGINATOR "The person or organization from whom the package originally came" "$AUTHOR_NAME"
+prompt APPLICATION_HOME_PAGE "The package's home page URL" "https://$REMOTE/$OWNER/$REPOSITORY"
+
+echo "$DESCRIPTION" > .git/description
+
+while read -r var; do
+    var_name="${var%=*}"
+    var_value="${var#*=\"}"
+    var_value="${var_value%\"}"
+
+    fd . --hidden --type file --exec sed --in-place "s|%\bINIT_$var_name\b|$var_value|"
+done < "$replacement_file"
+# vim: ft=sh
diff --git a/common/shell_line_editor.sh b/common/shell_line_editor.sh
new file mode 100644
index 0000000..5e38ef4
--- /dev/null
+++ b/common/shell_line_editor.sh
@@ -0,0 +1,217 @@
+#! /usr/bin/env sh
+# Taken in verbatim from: https://unix.stackexchange.com/a/113450, and somewhat changed
+
+LE_print_debug() {
+    LE_debug="$1"
+    LE_debug_msg="$2"
+    [ -n "$LE_debug" ] && printf "\nDBG: (%s)\n" "$LE_debug_msg" > outfile.debug
+}
+
+LE() {
+  # Shell Line Editor. Extremely slow and stupid code. However it
+  # should work on ansi/vt100/linux derived terminals on POSIX
+  # systems.
+  # Understands some emacs key bindings: CTRL-(A,B,D,E,F,H,K,L)
+  # plus the CTRL-W and CTRL-U normal killword and kill.
+  # no Meta-X key, but handling of <Left>, <Right>, <Home>, <End>
+  # <Suppr>.
+  #
+  # Args:
+  #  [1]: prompt (\x sequences recognized, defaults to "")
+  #  [2]: max input length (unlimited if < 0, (default))
+  #  [3]: fill character when erasing (defaults to space)
+  #  [4]: initial value.
+  #  [5]: whether to output debugfiles (outfile.debug and outfile.raw.debug)
+  # Returns:
+  #  0: OK
+  #  1: od(d) error or CTRL-C hit
+
+  LE_prompt="$1"
+  LE_max=${2--1}
+  LE_fill=${3-" "}
+  LE_debug="$5"
+
+  LE_backward() {
+    LE_substract="$1"
+    while [ -n "$LE_substract" ]; do
+      printf '\b%s' "$2"
+      LE_substract=${LE_substract%?}
+    done
+  }
+
+  LE_fill() {
+    LE_substract="$1"
+    while [ -n "$LE_substract" ]; do
+      printf '%s' "$LE_fill"
+      LE_substract=${LE_substract%?}
+    done
+  }
+
+  # Used but not right now
+  # shellcheck disable=2016
+  LE_restore='stty "$LE_tty"
+              LC_COLLATE='${LC_COLLATE-"; unset LC_COLLATE"}
+
+  # LE_tty is used in the restore above
+  # shellcheck disable=2034
+  LE_ret=1 LE_tty=$(stty -g) LC_COLLATE=C
+
+  # text on the right of the cursor
+  LE_left=$4
+  # text on the left of the cursor
+  LE_right=''
+
+  # Tell the terminal to show us every char inputted
+  stty -icanon -echo -isig min 3 time 1 -istrip
+  printf '%b%s' "$LE_prompt" "$LE_left"
+
+  # clear the output
+  [ -n "$LE_debug" ] && printf "" > outfile.debug
+  [ -n "$LE_debug" ] && printf "" > outfile.raw.debug
+
+  # The value needs to be split for it to work (and it's either way just numbers)
+  # shellcheck disable=2046
+  while set -- $(dd bs=3 count=1 2> /dev/null | od -vAn -to1); do
+    while [ "$#" -gt 0 ]; do
+      [ -n "$LE_debug" ] && printf "%b" "\0$1" >> outfile.debug
+      [ -n "$LE_debug" ] && printf "%s " "$1" >> outfile.raw.debug
+      LE_current_key=$1
+      shift
+
+      # 033 is ^[ (`printf "\\$1\n" | cat -v`)
+      if [ "$LE_current_key" = 033 ]; then
+        case "$1$2$3" in
+          # [ C | O C -> ^F forward
+          133103*|117103*) shift 2; LE_current_key=006;;
+          # [ D | O D -> ^B backward
+          133104*|117104*) shift 2; LE_current_key=002;;
+          # [ H | O H -> ^A beginning of line
+          133110*|117110*) shift 2; LE_current_key=001;;
+          # [ P | O P -> ^D del char
+          133120*|117120*) shift 2; LE_current_key=004;;
+          # [ F | O F -> ^E end of line
+          133106*|117106*) shift 2; LE_current_key=005;;
+          # [ 1 ~ -> ^A beginning of line
+          133061176) shift 3; LE_current_key=001;;
+          # [ 4 ~ -> ^E end of line
+          133064176) shift 3; LE_current_key=005;;
+          # [ 3 ~ -> ^D del char
+          133063176) shift 3; LE_current_key=004;;
+          # [ | O
+          133*|117*)
+            shift
+            # Is $1 in ge 0 AND le 9 OR eq ';'?
+            # These are control sequences for things like colors; Ignore them
+            while [ "0$1" -ge 060 ] && [ "0$1" -le 071 ] ||
+                  [ "0$1" -eq 073 ]; do
+              shift
+            done;;
+        esac
+      fi
+
+      case "$LE_current_key" in
+        001) # ^A beginning of line
+          LE_backward "$LE_left"
+          LE_right="$LE_left$LE_right"
+          LE_left=;;
+        002) # ^B backward
+          if [ "$LE_left" = "" ]; then
+            # bell
+            printf '\a'
+            LE_print_debug "$LE_debug" "backward with empty left"
+          else
+            printf '\b'
+            LE_tmp="${LE_left%?}"
+            LE_right="${LE_left#"$LE_tmp"}$LE_right"
+            LE_left="$LE_tmp"
+          fi;;
+        003) # CTRL-C
+          break 2;;
+        004) # ^D del char
+          if [ "$LE_right" = "" ]; then
+            # bell (tell the user that the line is empty)
+            printf '\a'
+            LE_print_debug "$LE_debug" "delete with empty right"
+          else
+            LE_right="${LE_right#?}"
+            printf '%s\b' "$LE_right$LE_fill"
+            LE_backward "$LE_right"
+          fi;;
+        012|015) # NL or CR
+          LE_ret=0
+          break 2;;
+        005) # ^E end of line
+          printf '%s' "$LE_right"
+          LE_left="$LE_left$LE_right"
+          LE_right=;;
+        006) # ^F forward
+          if [ "$LE_right" = "" ]; then
+            # bell (tell the user that the line is empty)
+            printf '\a'
+            LE_print_debug "$LE_debug" "forward with empty right"
+          else
+            LE_tmp="${LE_right#?}"
+            LE_left="$LE_left${LE_right%"$LE_tmp"}"
+            printf %s "${LE_right%"$LE_tmp"}"
+            LE_right="$LE_tmp"
+          fi;;
+        010|177) # backspace or del
+          if [ "$LE_left" = "" ]; then
+            # bell
+            printf '\a'
+            LE_print_debug "$LE_debug" "backspace with empty left"
+          else
+            printf '\b%s\b' "$LE_right$LE_fill"
+            LE_backward "$LE_right"
+            LE_left="${LE_left%?}"
+          fi;;
+        013) # ^K kill to end of line
+          LE_fill "$LE_right"
+          LE_backward "$LE_right"
+          LE_right=""
+          ;;
+        014) # ^L redraw
+          printf '\r%b%s' "$LE_prompt" "$LE_left$LE_right"
+          LE_backward "$LE_right";;
+        025) # ^U kill line
+          LE_backward "$LE_left"
+          LE_fill "$LE_left$LE_right"
+          LE_backward "$LE_left$LE_right"
+          LE_left=""
+          LE_right=""
+          ;;
+        027) # ^W kill word
+          if [ "$LE_left" = "" ]; then
+            # bell
+            printf '\a'
+          else
+            LE_tmp="${LE_left% *}"
+            LE_backward "${LE_left#"$LE_tmp"}"
+            LE_fill "${LE_left#"$LE_tmp"}"
+            LE_backward "${LE_left#"$LE_tmp"}"
+            LE_left="$LE_tmp"
+          fi;;
+        # Print the received key, as it did not match a special key
+        [02][4-7]?|[13]??) # 040 -> 177, 240 -> 377
+                           # was assuming iso8859-x at the time
+          if [ "$LE_max" -gt 0 ] && LE_tmp="$LE_left$LE_right" \
+             && [ "${#LE_tmp}" -eq "$LE_max" ]; then
+            # bell, when the user is trying to cross the line limit
+            printf '\a'
+            LE_print_debug "$LE_debug" "max output reached"
+          else
+            LE_left="$LE_left$(printf '%b' "\0$LE_current_key")"
+            printf '%b%s' "\0$LE_current_key" "$LE_right"
+            LE_backward "$LE_right"
+          fi;;
+        *)
+          LE_print_debug "$LE_debug" "key not recognized: $(printf "%b" "\0$LE_current_key")"
+          printf '\a';;
+      esac
+    done
+  done
+  eval "$LE_restore"
+  REPLY=$LE_left$LE_right
+  echo
+  return "$LE_ret"
+}