#!/bin/bash
#  output - Script output support library
#  lib_level: 0

set -e

######
# Settings

# timestamps - If true, prefixes stderr timestamps
timestamps=${timestamps:-true}

# nanoseconds - If non-empty, timestamp displays nanoseconds.
nanoseconds=${nanoseconds}

# app_log_hook - name of function that implements app_log_pipe
app_log_hook=app_log_stub

# error_usage_hook - name of function that implements error_usage
error_usage_hook=error_usage_stub

core_output_config_init() {
	lib_setting_vars timestamps
	lib_setting_vars --null nanoseconds
	lib_setting_vars app_log_hook error_usage_hook
}


######
# Logging Hook

# app_log - Calls app_log_hook
app_log() { $app_log_hook "$@"; }

# script_log_pipe_stub - This definition is a temporary handler for debugging
#   library loading.  When the script library is loaded, it is replaced
#   by the final version located therein.
app_log_stub() { cat; }


######
# Output

timestamp() { ! $timestamps || date +"[%H:%M:%S${nanoseconds:+.%N}]"; }

_app_echo() { if $logging; then echo "$@" | app_log; else echo "$@"; fi; }
app_echo() { _app_echo -e $(timestamp) "$*"; }
app_echo_n() { _app_echo -en $(timestamp) "$*"; }

app_msg() { app_echo "${script[*]} $*"; }
app_msg_if() {
	local x=$1
	shift
	if $x; then
		app_msg "$@" >&2
	else
		app_msg "$@" >/dev/null
	fi
}


######
# Information and errors

error() { app_msg_if true "ERROR: $*"; stack_trace; false; }
warn() { app_msg_if $(as_bool_not $quiet) "WARN: $*"; }
info() { app_msg_if $verbose "INFO: $*"; }
debug() { app_msg_if $debug "DEBUG: $*"; }


######
# Error Usage Hook

# error_usage - print an error and current command usage
error_usage() { $error_usage_hook "$@"; }

# error_usage_stub - This stub prints an unadorned error; the 'commands'
#   library provides a version to print the usage information.
error_usage_stub() { error "$1"; }


######
# Assertion support

_assert() {
	local _efunc=$1
	local _err=$2
	shift 2
	"$@" || $_efunc "$_err"
}

assert() { _assert error "$@"; }
assert_usage() { _assert error_usage "$@"; }


######
# Stack traces

stack_raw() {
	echo "FUNCNAME=( ${FUNCNAME[*]} )"
	echo "BASH_SOURCES=( ${BASH_SOURCE[*]} )"
	echo "BASH_LINENO=( ${BASH_LINENO[*]} )"
}

stack_trace() {
	debug "Stack trace:"
	local depth="${#FUNCNAME[@]}"
	for_each _stack_dump $(seq 2 $(($depth - 1)))
}

_stack_dump() {
	local frame=$1
	local func="${FUNCNAME[$frame]}"
	local file=${BASH_SOURCE[$frame]}
	file=${file#$libdir/}
	file=${file%.sh}
	local lineno="${BASH_LINENO[$(($frame - 1))]}"
	debug "$((frame - 2)): $func ($file:$lineno)"
}