#!/usr/bin/env bash
# ------------------------------------------------------------------------------
# Description
#   "Modular" bash_profile.
#     - First executes every script in header/active to output a custom terminal
#       header or welcome screen.
#     - Then sources the configs in configs/
#       * configs/active/: sources every file found recursively.
#       * configs/prompt/: prompts the user to source every file
#         found recursively.
#
# Usage
#   The directory structure must be as follows:
#       ├─ header
#       │  ├─ active
#       │  └─ inactive
#       ├─ configs
#       │  ├─ active
#       │  ├─ inactive
#       │  └─ prompt
#       └─ bash_profile
#
#   Then make sure bash_profile is sourced at bash startup, for example by
#   setting a symbolic link this way:
#       ln -s /path/to/this/file $HOME/.bash_profile
#
# Dependencies
#   * Commands: awk, tput, read, source, test, readlink.
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Constants
# ------------------------------------------------------------------------------

# Formatting constants
export BOLD=`tput bold`
export UNDERLINE_ON=`tput smul`
export UNDERLINE_OFF=`tput rmul`
export TEXT_BLACK=`tput setaf 0`
export TEXT_RED=`tput setaf 1`
export TEXT_GREEN=`tput setaf 2`
export TEXT_YELLOW=`tput setaf 3`
export TEXT_BLUE=`tput setaf 4`
export TEXT_MAGENTA=`tput setaf 5`
export TEXT_CYAN=`tput setaf 6`
export TEXT_WHITE=`tput setaf 7`
export BACKGROUND_BLACK=`tput setab 0`
export BACKGROUND_RED=`tput setab 1`
export BACKGROUND_GREEN=`tput setab 2`
export BACKGROUND_YELLOW=`tput setab 3`
export BACKGROUND_BLUE=`tput setab 4`
export BACKGROUND_MAGENTA=`tput setab 5`
export BACKGROUND_CYAN=`tput setab 6`
export BACKGROUND_WHITE=`tput setab 7`
export RESET_FORMATTING=`tput sgr0`


# ------------------------------------------------------------------------------
# Functions
# ------------------------------------------------------------------------------


# Print the header.
bash-profile_print-header () {
  # Loop through files in the header folder
  for file in $BASH_PROFILE_LOCATION/header/active/*; do
    
    # If this is a file, execute it
    if [ -f "$file" ]; then
      "$file"
    fi
  done
}


# Ask the user a "yes/no" question. Defaults to "no".
#
# Arguments
#     1 (optional) the question to ask.
bash-profile_ask () {
  read -s -n1 -p "$@ [y/N] " ans
  case "$ans" in
    y*|Y*)
      return 0
      ;;
    *)
      return 1
      ;;
  esac
}


# Source the given file.
#
# Arguments
#     1 (required) the file to source.
#
# Options
#     --ask Prompt the user before.
#           To be put before first argument.
bash-profile_load-bash-config () {
  
  # Handle the --ask option
  if [ $1 = "--ask" ]; then
    shift
    ask=0
  else
    ask=1
  fi

  # Extract a readable name from the file name
  # Example: "/home/user/folder/010_Aliases and functions.sh" => "Aliases and functions"
  config_name=$(expr match "`echo $@`" '.*[/_]\([^\.]*\)')
  
  # Ask if needed
  if [ $ask -eq 0 ]; then
    if ! bash-profile_ask "Load $config_name ?"; then
      echo -e `tput rc; tput ed`$CONFIGS_LINE
      return 1
    fi
  fi

  # Source the file
  source "`echo $@`" &> /tmp/bash_profile_config_out.log
  
  # Append the output to the report if needed
  if [ -s /tmp/bash_profile_config_out.log ]; then
    echo "${TEXT_BLUE}${BOLD}$config_name${RESET_FORMATTING}▸ " >> /tmp/bash_profile_configs_out
    (cat /tmp/bash_profile_config_out.log | sed -e "s/\(.*\)/\ \ \1/g"; echo) >> /tmp/bash_profile_configs_out
  fi
  
  # Update the configurations line
  if [ -z "${CONFIGS_LINE}" ]; then
    export CONFIGS_LINE="${TEXT_BLUE}${BOLD}Configs▸ ${RESET_FORMATTING} $config_name"
  else
    export CONFIGS_LINE=${CONFIGS_LINE}" ${TEXT_BLUE}|${RESET_FORMATTING} $config_name"
  fi
  
  # Print the line at the last saved position
  echo -e `tput rc; tput ed`$CONFIGS_LINE
}


# Source the files recursively in the given folder.
#
# Arguments
#     1 (required) the folder to process.
#
# Options
#     --ask Prompt the user before loading each script.
#           To be put before first argument.
bash-profile_load-folder-bash-configs () {
  
  # Handle the --ask option
  if [ $1 = "--ask" ]; then
    shift
    load_opts="--ask"
  else
    load_opts=""
  fi
  
  # Declare a boolean to determine the success of the operation
  success=true
  
  # Escape spaces in the folder name
  local folder=`echo $1 | sed -e "s/ /\\ /g"`
  
  # Check that a valid folder was given
  if [ -d "$folder" ]; then
    
    # Check the folder is not empty
    if [ `ls "$folder" | wc -l` -ne 0 ]; then
    
      # Loop through files in the folder
      # (Trick: replace spaces in filenames with '&' to enter the for loop)
      for file in `find $folder/* -xtype f | sort | sed -e "s/ /\\&/g"`
      do
      
        # Restore spaces
        file=`echo $file | sed -e "s/\\&/ /g"`

        # Try loading the config
        bash-profile_load-bash-config $load_opts $file
        
      done
      
    fi
      
  # If this is not a valid folder
  else
    echo "${TEXT_RED}${BOLD}'$1' is not a valid folder.${RESET_FORMATTING}"
    success=false
  fi
  
  # If something went wrong, exit
  if ! $success; then
    `exit 1`
  fi
}


# Load the configurations
bash-profile_load-configs () {
  # Save the current cursor position
  tput sc

  # Source scripts in active/
  bash-profile_load-folder-bash-configs "$BASH_PROFILE_LOCATION/configs/active"

  # Source scripts in prompt/ (ask first)
  bash-profile_load-folder-bash-configs --ask "$BASH_PROFILE_LOCATION/configs/prompt"
}


# Print the footer line.
bash-profile_print-footer () {
  local _WINDOW_Y=`tput cols`
  local _FOOTER_LINE_CHARACTER="_"
  echo -e ${BOLD}`echo ""|awk '
  {
    _SPACES = '${_WINDOW_Y}'
    while (_SPACES-- > 0) printf ("'${_FOOTER_LINE_CHARACTER}'")
  }'`${RESET_FORMATTING}
}


# Print the configurations output report.
bash-profile_print-configs-output() {
  if [ -s /tmp/bash_profile_configs_out ]; then
    cat /tmp/bash_profile_configs_out | head --lines=-1
    bash-profile_print-footer
  fi
}


# ------------------------------------------------------------------------------
# Main
# ------------------------------------------------------------------------------

# Resolve the real location of this file
export BASH_PROFILE_LOCATION="$(dirname "$(test -L "$BASH_SOURCE" && readlink "$BASH_SOURCE" || echo "$BASH_SOURCE")")"

# Local variables declarations
CONFIGS_LINE=""

# Clear the terminal
clear

# Clean traces from a previous execution
rm -f /tmp/bash_profile_configs_out

# Print the header
bash-profile_print-header

# Load the configurations
bash-profile_load-configs

# Print the footer
bash-profile_print-footer

# Print the configurations output
bash-profile_print-configs-output

# Unset all variables and functions to ensure their visibility stay local
unset CONFIGS_LINE
unset -f bash-profile_print-header
unset -f bash-profile_ask
unset -f bash-profile_load-bash-config
unset -f bash-profile_load-folder-bash-configs
unset -f bash-profile_print-configs-line
unset -f bash-profile_load-configs
unset -f bash-profile_print-footer