# A collection of commands to make it easier to build projects.

# Default `build` alias to select a `build-dir` then invoke a build, using an
# alias means the configured build command's completion works out of the box.
alias build="build-dir --build"

# Detect installed debugger and set the `debug` alias to debug a program with
# command line arguments.
if [ `uname` = Linux ]; then
  if [[ "`vim --version`" =~ "^VIM - Vi IMproved 8\.1.*$" ]]; then
    autoload -U regexp-replace
    function vimdebug() {
      # For each item in $* replace * and \* and then replace \ with \\
      local args=()
      for arg in "$@"; do
        regexp-replace arg '\*' '\\*'
        args+=($arg)
      done
      vim "+packadd termdebug" "+TermdebugCommand $args"
    }
    alias debug='vimdebug'
  elif which cgdb &> /dev/null; then
    alias debug='cgdb --args'
  elif which gdb &> /dev/null; then
    alias debug='gdb --args'
  fi
elif [ `uname` = Darwin ]; then
  which lldb &> /dev/null && \
    alias debug='lldb --'
fi

# Interactively choose a `~build` directory for `build` to build.
build-dir() {
  local usage='usage: build-dir [-h] [--build] [<directory>]'
  local -a help do_build
  zparseopts -D h=help -help=help -build=do_build
  if [[ -n $help ]]; then
    cat << EOF
$usage

Find and select the current build directory interactively.

positional arguments:
  <directory> the build directory to select

optional arguments:
  -h, --help  show this help message and exit
  --build     invoke a build after selection
EOF
    return
  fi
  error() { echo "\e[31merror:\e[0m $1" }
  warning() { echo "\e[33mwarning:\e[0m $1" }
  local local_build_dir
  if [[ ${#*} -gt 1 ]]; then
    echo $usage
    error "unexpected position arguments: ${*[2,${#*}]}"; return 1
  elif [[ ${#*} -eq 1 ]]; then
    if [[ ! -d ${*[1]} ]]; then
      warning "directory not found: ${*[1]}"
    else
      local_build_dir=${*[1]}
    fi
  fi

  # If <directory> was not set begin selection
  if [[ -z $local_build_dir ]]; then
    # Find build directories
    local -a local_build_dirs
    for entry in `ls -A`; do
      [ -d $entry ] && [[ $entry =~ build* ]] && \
        local_build_dirs+=${entry/\//}
    done

    # Interactively select a build directory if more than 1 found
    integer index=0
    if [[ ${#local_build_dirs} -eq 0 ]]; then
      error "no build directories found"; return 1
    elif [[ ${#local_build_dirs} -gt 1 ]]; then
      zmodload zsh/curses && {
        # Get the size of the terminal
        local size=`stty size`
        integer height=${size% *}
        integer width=${size#* }

        # Create the window and hide the cursor
        zcurses init
        zcurses addwin build-dir $height $width 0 0

        # Hide the cursor for zcurses, trap SIGINT to ensure cleanup in
        # always-list occurs below
        tput civis; trap 'return 130' INT

        # Enter display loop
        local key keypad
        while (( 1 )); do
          zcurses clear build-dir

          # Add the prompt text
          zcurses move build-dir 1 1
          zcurses string build-dir 'Select a build directory:'

          # Add the selections text
          for (( i = 0; i < ${#local_build_dirs}; i++ )); do
            integer line=$i+3
            zcurses move build-dir $line 1
            [[ $index -eq $i ]] &&
              zcurses string build-dir "* " ||
              zcurses string build-dir "  "
            zcurses string build-dir ${local_build_dirs[$i+1]}
          done

          # Display the text the and wait for input
          zcurses refresh build-dir
          zcurses input build-dir key keypad

          # Handle user input
          case $key in
            (UP|k|$'\C-P')
              [[ $index -gt 0 ]] && index=$index-1 ;;
            (DOWN|j|$'\C-N')
              [[ $index -lt ${#local_build_dirs}-1 ]] && index=$index+1 ;;
            (ENTER|$'\n')
              break ;;
          esac
        done
      } always {
        # Restore the cursor and cleanup zcurses
        tput cvvis; tput cnorm
        zcurses delwin build-dir
        zcurses end
      }
    fi
  fi

  # On success setup the build directory for use
  if [[ $? -eq 0 ]]; then
    # Set the build directory from selection if empty
    [[ -z $local_build_dir ]] && \
      local_build_dir=${local_build_dirs[$index+1]}

    # If `build.ninja` exists in alias `ninja`, return.
    local build
    [ -f $local_build_dir/build.ninja ] && \
      build="ninja -C $local_build_dir"

    # If `Makefile` exists in alias `make`, return.
    if [ -f $local_build_dir/Makefile ]; then
      [ `uname` = Darwin ] && \
        local cpu_count=`sysctl -n hw.ncpu` ||
        local cpu_count=`grep -c '^processor' /proc/cpuinfo`
      build="make -j $cpu_count -C $local_build_dir"
    fi

    # If the build variable is not defined the command could not be determined
    if [ -z $build ]; then
      warning "build command detection failed: $local_build_dir"
      # Prompt user to enter a build command
      vared -p 'enter comand: ' build
    fi

    # Redefine the `build` alias and update the `~build` hash directory
    alias build="$build"
    hash -d build=$local_build_dir
    export build_dir=$local_build_dir

    # If `--build` is specified then evaluate the command.
    if [[ -n $do_build ]]; then
      eval build
    fi
  fi
}

# Build then run a target residing in `~build/bin`.
build-run() {
  local target=$1; shift 1
  eval build $target && ~build/bin/$target "$@"
}

# Build then debug a target residing in `~build/bin`.
build-debug() {
  local target=$1; shift 1
  eval build $target && debug ~build/bin/$target "$@"
}