#!/usr/bin/env bash

# Basic logging utility functions that can be used by scripts to log
# to files.  This helps keep console clean for TUI's.  Will log
# messages to all registered files, which allows each script to
# declare their own logging file, but also print logs into parent
# processes files, for ease of discovery.
#
# Supports warning and error flags.
#
# Errors and warnings get logged to the file and to the console.
#
#
# EXAMPLE SETUP:
#
# source $SCRIPTS/hypr/logging
# THIS=$(basename ${BASH_SOURCE[0]})
#
# # Setup logging file and label.
# setup-logging "/tmp/$THIS.log" $THIS
#
# function log() {
#   logging log --source ${BASH_SOURCE[0]} "$@"
# }
#
# log "My log message."
# log --warning "My warning message."
# log --error "My error message."
#

LOG_FILE=(${LOG_FILE:-})
LOG_INVOCATION_ID=${LOG_INVOCATION_ID:-}
LOG_LABEL=(${LOG_LABEL:-})
# Run in dry run mode, which just prints to the console and does
# not log to the files.
LOG_ENABLE_DRY_RUN=${LOG_ENABLE_DRY_RUN:-"0"}
SCRIPTS=${SCRIPTS:-$HOME/.local/scripts}

warn_flag="0"
error_flag="0"

__msg() {
  if [[ -z "$@" ]]; then
    echo -e "\e[31m[ERROR]:\e[0m No logs were supplied."
    exit 1
  fi
  if [[ $warn_flag == "1" ]]; then
    echo -e "\e[33m[WARN]:\e[0m $@"
  elif [[ $error_flag == "1" ]]; then
    echo -e "\e[31m[ERROR]:\e[0m $@"
  else
    echo "$@"
  fi
}

__ensure_setup() {
  if [[ -z $LOG_FILE ]] || [[ -z $LOG_INVOCATION_ID ]] || [[ -z $LOG_LABEL ]]; then
    echo -e "\e[31m[ERROR]:\e[0m Logging is not properly setup."
    echo "Perhaps you didn't call 'setup-logging' first."
    print_logger_env && exit 1
  fi
}

logging() {
  __ensure_setup

  # Reset flags
  log_flag="0"
  warn_flag="0"
  error_flag="0"
  source_file=""
  args=()

  while [[ $# -gt 0 ]]; do
    if [[ $1 == "-w" ]] || [[ $1 =~ ^--warn ]]; then
      log_flag="1"
      warn_flag="1"
    elif [[ $1 == "-e" ]] || [[ $1 =~ ^--error ]]; then
      log_flag="1"
      error_flag="1"
    elif [[ $1 == "-s" ]] || [[ $1 =~ ^--source ]]; then
      shift
      source_file="$1"
    elif [[ $1 == "log" ]]; then
      log_flag="1"
    else
      args+=("$1")
    fi
    shift
  done

  if [[ -z $source_file ]]; then
    echo -e "\e[31m[ERROR]:\e[0m Must supply the source file the logs originate from."
    exit 1
  fi

  if [[ -z $args ]]; then
    echo -e "\e[31m[ERROR]:\e[0m No log message supplied."
    exit 1
  fi

  msg="$(__msg ${args[@]})"

  if [[ $LOG_ENABLE_DRY_RUN == "0" ]]; then
    # Loop over log files logging message to each file.
    for i in "${!LOG_FILE[@]}"; do
      prefix="[id: $LOG_INVOCATION_ID][time: $($SCRIPTS/isosec)][label: ${LOG_LABEL[i]}][source: $source_file] : "
      m="$prefix $msg"
      echo -e "$m" >>${LOG_FILE[i]}
    done

    # Also log errors and warning messages to the console.
    if [[ $error_flag == "1" ]] || [[ $warn_flag == "1" ]]; then
      echo -e "[id: $LOG_INVOCATION_ID]: $msg"
    fi
  else
    # Dry run mode, so just log to the console
    echo -e "\e[34m[DRY RUN]:\e[0m $msg"
  fi
}

setup-logging() {
  label=""
  file=""

  if [[ "${#@}" == "1" ]]; then
    file="/tmp/$1.log"
    label="$1"
  else
    file="$1"
    label="$2"
  fi

  if [[ -z "$file" ]]; then
    echo -e "\e[31m[ERROR]:\e[0m Must supply a log file."
    exit 1
  fi

  if [[ -z "$label" ]]; then
    echo -e "\e[31m[ERROR]:\e[0m Must supply a logger label."
    exit 1
  fi

  LOG_FILE+=("$file")
  LOG_INVOCATION_ID=${LOG_INVOCATION_ID:-$RANDOM}

  if [[ -n "$LOG_LABEL" ]]; then
    LOG_LABEL+=("${LOG_LABEL[@]}=>$label")
  else
    LOG_LABEL+=("$label")
  fi
  export LOG_FILE
  export LOG_LABEL
  export LOG_INVOCATION_ID
}

print_logger_env() {
  echo "LOG_FILE: ${LOG_FILE[@]}"
  echo "LOG_INVOCATION_ID: $LOG_INVOCATION_ID"
  echo "LOG_LABEL: ${LOG_LABEL[@]}"
}

export -f setup-logging
export -f logging
export -f print_logger_env