Merge branch 'config-file' of ceda/Wish into master

Wish is now configured by a config file (although WISH_PLUGINS and
WISH_RIGHT_PLUGINS are still used as a fallback if no config file is
found. This way old setups won't break). Config file allows for higher
customization and re-use of plugins and is easier to maintain for
users. Add gINIe parser to Wish. Parse a gINIe config file for wish
config. Wrappers around plugins are created to allow re-use with
multiple configs and themes.

.gitignore

@@ -0,0 +1,3 @@
+__pycache__/
+*.pyc
+config.gie

config.default.gie

@@ -0,0 +1,59 @@
+# vim: set ft=dosini:
+#
+# Comments start with a # or ; and always exist on a line of their own.
+#
+# Key value pairs are in the form of key = value. Keys cannot have whitespaces
+# or = in them. Values can have any character as part of them. Surrounding
+# spaces in values are stripped away. To keep surrounding spaces as a part of
+# the value. Although, keys are case-sensitive in gINIe, wish treats them case-
+# insensitively.
+#
+# Block names are enclosed in [] (e.g. [core]). Block names are case sensitive.
+# All key value pairs after a block starts and before the next block begins are
+# considered a part of that block. All key value pairs must be in a block.
+#
+# Available Blocks:
+#
+#   core: Core block configures Wish itself. Available keys are:
+#        - auto_newline: Automatically add a newline if last line of output
+#          doesn't end in newline. (0 to disable, 1 to enable)
+#        - theme: Wish theme.
+#        - powerline: Enable / Disable powerline. (0 to disable, 1 to enable)
+#
+#   plugin: Adds a plugin to the section the block is added to. All config for
+#           that plugin goes there. The key "name" defines the plugin to use.
+#           Plugin blocks outside a section are ignored.
+#
+# Section names are enclosed in || (e.g. |left|). All blocks after a section
+# starts and before the next section begins are considered a part of that
+# section. Blocks don't necessarily need to be in a section.
+#
+# Available sections are left, right for left prompt and right prompt
+# respectively.
+
+[core]
+auto_newline = 1
+powerline = 1
+theme = plain
+
+|left|
+[plugin]
+name = exit_code_smiley
+
+[plugin]
+name = bg_jobs
+
+[plugin]
+name = date
+format = %d %b %H:%M
+
+[plugin]
+name = path
+
+[plugin]
+name = newline
+
+[plugin]
+name = vcs
+
+|right|

ginie.py

@@ -0,0 +1,135 @@
+#!/usr/bin/env python3
+"gINIe Parser for Wish"
+
+import re
+import sys
+
+
+class GinieParseError(ValueError):
+    "Exception Class for errors in"
+
+
+def loads(string):
+    """
+    Deserialize `string` (a `str` instance containing a gINIe document)
+    into a Python list.
+
+    Return Value: List of `block` and `section` dicts
+
+    `block` dicts are of form
+    {
+        'type': 'block',
+        'name': 'name_of_block_as_in_config',
+        'config': {}
+    }
+    where `name` and `config` keys are based on the gINIe document.
+
+    `section` dicts are of form
+
+    {
+        'type': 'block',
+        'name': 'name_of_block_as_in_config',
+        'blocks': []
+    }
+    where `name` and `blocks` keys are based on the gINIe document and blocks
+    is a list of block dicts found in the section.
+    """
+    config = []
+    section_re = re.compile(r"^\|(?P<section>.+)\|$")
+    block_re = re.compile(r"^\[(?P<block>[^\]]*)\]$")
+    line_re = re.compile(r"^\s*(?P<key>[^\s=]+)(\s*)=\s*?(?P<value>.*)$")
+    empty_re = re.compile(r"^\s*$")
+    comment_re = re.compile(r"^\s*(#|;)")
+    current_block = None
+    current_section = None
+    for idx, line in enumerate(string.splitlines()):
+        idx += 1  # Since line numbers begin with 1
+        # Skip comments and empty lines
+        if empty_re.match(line) or comment_re.match(line):
+            continue
+
+        # Section parsing
+        if line.startswith("|"):
+            match = section_re.match(line)
+            if match is None:
+                err = "Invalid line {}".format(idx)
+                raise GinieParseError(err)
+            current_section = {
+                "type": "section",
+                "name": match.group("section"),
+                "blocks": []
+            }
+            config.append(current_section)
+            continue
+
+        # Block Parsing
+        if line.startswith("["):
+            match = block_re.match(line)
+            if match is None:
+                err = "Invalid block name on line {}".format(idx)
+                raise GinieParseError(err)
+            current_block = {
+                "type": "block",
+                "name": match.group("block"),
+                "config": {}
+            }
+            if current_section is None:
+                config.append(current_block)
+            else:
+                current_section["blocks"].append(current_block)
+            continue
+
+        # If it is neither a comment, nor a section, nor a block, it has to be
+        # a key, value pair.
+        if current_block is None:
+            raise GinieParseError("Found lines outside a block")
+
+        match = line_re.match(line)
+        if match is None:
+            raise GinieParseError("Invalid line {}: {}".format(idx, line))
+
+        value = match.group('value').strip()
+        if value:
+            if value[0] == value[-1] == "'" or value[0] == value[-1] == '"':
+                value = value[1:-1]
+        current_block["config"][match.group('key').strip()] = value
+
+    return config
+
+
+def load(file):
+    """
+    Deserialize `file` (a file-like object containing a gINIe document)
+    into a Python list.
+
+    Return Value: List of `block` and `section` dicts
+
+    `block` dicts are of form
+    {
+        'type': 'block',
+        'name': 'name_of_block_as_in_config',
+        'config': {}
+    }
+    where `name` and `config` keys are based on the gINIe document.
+
+    `section` dicts are of form
+
+    {
+        'type': 'block',
+        'name': 'name_of_block_as_in_config',
+        'blocks': []
+    }
+    where `name` and `blocks` keys are based on the gINIe document and blocks
+    is a list of block dicts found in the section.
+    """
+    return loads(file.read())
+
+
+if __name__ == "__main__":
+    if len(sys.argv) == 1:
+        print("Usage: {} file.gie|-".format(sys.argv[0]))
+    elif sys.argv[1] == '-':
+        print(load(sys.stdin))
+    else:
+        with open(sys.argv[1]) as source:
+            print(load(source))

install.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 if hash git; then
-	git clone https://gitlab.com/ceda_ei/wish.git $HOME/.config/wish.git
+	git clone https://gitlab.com/ceda_ei/Wish.git $HOME/.config/wish
 else
 	curl https://gitlab.com/ceda_ei/wish/-/archive/master/wish-master.tar -o /tmp/wish.tar
 	mkdir $HOME/.config 2> /dev/null
@@ -10,12 +10,11 @@ else
 	mv wish-master/ wish/
 	mv wish/ $HOME/.config/
 fi
+cp $HOME/.config/wish/config.default.gie $HOME/.config/wish/config.gie
 
 cat >> ~/.bashrc <<EOF
 
 # Wish
-
-WISH_PLUGINS=(exit_code_smiley bg_jobs date path newline vcs)
-WISH_THEME=plain
-source ~/.config/wish/wish.sh
+WISH_CONFIG_FILE="$HOME/.config/wish/config.gie"
+source $HOME/.config/wish/wish.sh
 EOF

plugins/custom_text.sh

@@ -9,10 +9,10 @@ function wish_custom_text_end() {
 function wish_custom_text_set_colors() {
 	WISH_CUSTOM_TEXT_FG=${WISH_CUSTOM_TEXT_FG:-$WISH_DEFAULT_FG}
 	WISH_CUSTOM_TEXT_BG=${WISH_CUSTOM_TEXT_BG:-$WISH_DEFAULT_BG}
-	local default_text='To set custom text here, add WISH_CUSTOM_TEXT="your text" in ~/.bashrc'
-	WISH_CUSTOM_TEXT=${WISH_CUSTOM_TEXT:-$default_text}
+	local default_text='To set custom text here, add text="your text" in your config'
+	WISH_CUSTOM_TEXT_TEXT=${WISH_CUSTOM_TEXT_TEXT:-$default_text}
 }
 
 function wish_custom_text_main() {
-	wish_append $WISH_CUSTOM_TEXT_BG $WISH_CUSTOM_TEXT_FG "$WISH_CUSTOM_TEXT"
+	wish_append $WISH_CUSTOM_TEXT_BG $WISH_CUSTOM_TEXT_FG "$WISH_CUSTOM_TEXT_TEXT"
 }

plugins/path_powerline.sh

@@ -10,10 +10,45 @@ function wish_path_powerline_set_colors() {
 	WISH_PATH_POWERLINE_FG=${WISH_PATH_POWERLINE_FG:-$WISH_DEFAULT_FG}
 	WISH_PATH_POWERLINE_BG=${WISH_PATH_POWERLINE_BG:-$WISH_DEFAULT_BG}
 	WISH_PATH_POWERLINE_NO_WRITE_SUFFIX=${WISH_PATH_POWERLINE_NO_WRITE_SUFFIX:- }
+	WISH_PATH_POWERLINE_MAX_PERC=${WISH_PATH_POWERLINE_MAX_PERC:-0}
+}
+
+function wish_path_lensum() {
+	sum=0
+	for i in $*; do
+		sum=$(($sum + ${#i}))
+	done
+	echo $sum
+}
+
+function wish_path_powerline_shrink() {
+	local IFS='/'
+	local path=( $1 )
+	local max=$(( $2 - 3 * ${#path[@]} ))
+	for ((i=0; i <$((${#path[@]} - 1)); i++)); do
+		path[$i]=${path[$i]:0:1}
+		if [[ $(wish_path_lensum ${path[@]}) -lt $max ]]; then
+			local short_path=""
+			for i in ${path[@]}; do
+				short_path+="$i/"
+			done
+			echo "${short_path%/}"
+			return
+		fi
+	done
+	local short_path=""
+	for i in ${path[@]}; do
+		short_path+="$i/"
+	done
+	echo "${short_path%/}"
 }
 
 function wish_path_powerline_main() {
 	local path="${PWD/#$HOME/\~}"
+	if [[ $WISH_PATH_POWERLINE_MAX_PERC -ne 0 && ${#path} -ge $WISH_PATH_POWERLINE_MAX_LEN ]] ; then
+		local max=$(($WISH_PATH_POWERLINE_MAX_PERC * $(wish_remaining_chars) / 100))
+		local path=$(wish_path_powerline_shrink "$path" "$max")
+	fi
 	local path="${path//\//  }"
 	if [[ -w $PWD ]]; then
 		local path=" $path "

plugins/vcs.sh

@@ -10,7 +10,7 @@ function wish_vcs_set_colors() {
 	WISH_VCS_FG=${WISH_VCS_FG:-$WISH_DEFAULT_FG}
 	WISH_VCS_BG=${WISH_VCS_BG:-$WISH_DEFAULT_BG}
 	WISH_VCS_GIT_SYMBOL=${WISH_VCS_GIT:-}
-	WISH_VCS_DEFAULT=${WISH_VCS_DEFAULT:-$}
+	[[ -v WISH_VCS_DEFAULT ]] || WISH_VCS_DEFAULT="$"
 	WISH_VCS_GIT_UNTRACKED_SYMBOL=${WISH_VCS_GIT_UNTRACKED_SYMBOL:-●}
 }
 
@@ -32,7 +32,7 @@ function wish_vcs_main() {
 		fi
 		wish_append $WISH_VCS_BG $WISH_VCS_FG "$git"
 	else
-		wish_append $WISH_VCS_BG $WISH_VCS_FG " $WISH_VCS_DEFAULT "
+		wish_append $WISH_VCS_BG $WISH_VCS_FG "$WISH_VCS_DEFAULT"
 	fi
 }
 

themes/gradient.sh

@@ -5,7 +5,19 @@ local gradient=(226 118 37 66 60 237 233)
 local fg_gradient=(16 16 16 16 16 15 15)
 local j=0
 for i in ${WISH_PLUGINS[@]}; do
-	[[ $i == "newline" ]] && j=0 && continue
+	[[ $i =~ newline$ ]] && j=0 && continue
+	eval WISH_${i^^}_BG=${gradient[$j]}
+	eval WISH_${i^^}_FG=${fg_gradient[$j]}
+	((j++))
+	if [[ $j -eq ${#gradient[@]} ]]; then
+		j=0
+	fi
+done
+
+j=0
+for ((idx=$((${#WISH_RIGHT_PLUGINS[@]} - 1)); idx >= 0; idx--)); do
+	i=${WISH_RIGHT_PLUGINS[$idx]}
+	[[ $i =~ newline$ ]] && j=0 && continue
 	eval WISH_${i^^}_BG=${gradient[$j]}
 	eval WISH_${i^^}_FG=${fg_gradient[$j]}
 	((j++))

themes/lowfi-neon.sh

@@ -5,7 +5,19 @@ local i
 local gradient=(e7c547 c0e551 82e35a 62e177 6bdfb3 73d4dd 7aa6da)
 local j=0
 for i in ${WISH_PLUGINS[@]}; do
-	[[ $i == "newline" ]] && j=0 && continue
+	[[ $i =~ newline$ ]] && j=0 && continue
+	eval WISH_${i^^}_BG=-1
+	eval WISH_${i^^}_FG=${gradient[$j]}
+	((j++))
+	if [[ $j -eq ${#gradient[@]} ]]; then
+		j=0
+	fi
+done
+
+j=0
+for ((idx=$((${#WISH_RIGHT_PLUGINS[@]} - 1)); idx >= 0; idx--)); do
+	i=${WISH_RIGHT_PLUGINS[$idx]}
+	[[ $i =~ newline$ ]] && j=0 && continue
 	eval WISH_${i^^}_BG=-1
 	eval WISH_${i^^}_FG=${gradient[$j]}
 	((j++))

themes/plain.sh

@@ -1,7 +1,7 @@
 WISH_DEFAULT_BG=-1
 WISH_DEFAULT_FG=-1
 WISH_POWERLINE=0
-for i in ${WISH_PLUGINS[@]}; do
+for i in ${WISH_PLUGINS[@]} ${WISH_RIGHT_PLUGINS[@]}; do
 	eval WISH_${i^^}_BG=-1
 	eval WISH_${i^^}_FG=-1
 done

themes/rgb_gradient.sh

@@ -5,7 +5,19 @@ local gradient=(ffff5f 7ad767 66b097 5e7388 534d61 3a3338 121212)
 local fg_gradient=(000000 000000 000000 000000 000000 ffffff ffffff)
 local j=0
 for i in ${WISH_PLUGINS[@]}; do
-	[[ $i == "newline" ]] && j=0 && continue
+	[[ $i =~ newline$ ]] && j=0 && continue
+	eval WISH_${i^^}_BG=${gradient[$j]}
+	eval WISH_${i^^}_FG=${fg_gradient[$j]}
+	((j++))
+	if [[ $j -eq ${#gradient[@]} ]]; then
+		j=0
+	fi
+done
+
+j=0
+for ((idx=$((${#WISH_RIGHT_PLUGINS[@]} - 1)); idx >= 0; idx--)); do
+	i=${WISH_RIGHT_PLUGINS[$idx]}
+	[[ $i =~ newline$ ]] && j=0 && continue
 	eval WISH_${i^^}_BG=${gradient[$j]}
 	eval WISH_${i^^}_FG=${fg_gradient[$j]}
 	((j++))

wish.py

@@ -0,0 +1,140 @@
+#!/usr/bin/env python3
+"""
+Generate function wrappers from config for wish.
+
+wish.py works by writing plugins which are isolated from the global plugins.
+It assigns all the config to relevant variables inside a wrapper. e.g.
+
+If the config file is
+
+```
+|left|
+[plugin]
+name = date
+format = %F
+```
+
+wish.py creates a wrapper around date as 0_date where 0 is the index of plugin.
+Inside the wrapper, in each function, it sets WISH_DATE_FORMAT="%F" and
+WISH_DATE_BG=$WISH_0_DATE_BG (same for FG), so the plugin sees its config as
+defined in the config file. After calling the plugin's relevant function, it
+sets WISH_0_DATE_BG=$WISH_DATE_BG (same for FG) in case, the plugin has changed
+it). This allows multiple instances of the same plugin to coexist with
+different config and different themes.
+"""
+
+from os.path import isfile
+import shlex
+import sys
+
+import ginie
+
+
+def parse_core(core):
+    "Parses a core block"
+    config = core["config"]
+    for key in core["config"]:
+        print("WISH_{}={}".format(key.upper(), shlex.quote(config[key])))
+
+
+def parse_plugin(plugin, plugin_idx):
+    "Parses a plugin and writes a wrapper around it"
+    config = plugin["config"]
+    try:
+        plugin_name = config["name"].strip().lower()
+        config["name"] = plugin_name
+    except KeyError:
+        return False
+
+    keys_from_source = ("BG", "FG")
+    for j in ("start", "end", "set_colors", "main"):
+        print("function wish_{}_{}_{}()".format(plugin_idx, plugin_name, j))
+        print("{")
+        for key in keys_from_source:
+            print("\tlocal WISH_{0}_{2}=$WISH_{1}_{0}_{2}".format(
+                plugin_name.upper(),
+                plugin_idx,
+                key.upper()
+            ))
+        for key in config:
+            if key == "name":
+                continue
+            print("\tlocal WISH_{}_{}={}".format(plugin_name.upper(),
+                                                 key.upper(),
+                                                 shlex.quote(config[key])))
+        print("\twish_{}_{} $*".format(plugin_name, j))
+        print("\tlocal err=$?")
+        for key in keys_from_source:
+            print("\tWISH_{1}_{0}_{2}=$WISH_{0}_{2}".format(
+                plugin_name.upper(),
+                plugin_idx,
+                key.upper()
+            ))
+        print("\treturn $err")
+        print("}")
+    return True
+
+
+def print_plugin_list(name, array, always=False):
+    "Prints a list of plugins as a bash array"
+    if array or always:
+        print("{}=(".format(name))
+        for plugin in array:
+            print("\t" + plugin)
+        print(")")
+
+
+def main():
+    "Parse a config file passed as first argument"
+    config_file = []
+    for file_name in sys.argv[1:]:
+        if isfile(file_name):
+            with open(file_name) as file:
+                config_file += ginie.load(file)
+        else:
+            print("echo Invalid config file: {}".format(
+                shlex.quote(file_name)))
+
+    plugin_idx = 0
+    plugins_to_source = []
+    left_plugins = []
+    right_plugins = []
+    for i in config_file:
+        kind = i["type"]
+        name = i["name"]
+        # Parse core blocks outside a section.
+        # No other blocks outside a section need to be parsed for now.
+        if kind == "block" and name == "core":
+            parse_core(i)
+        elif kind == "section":
+            # All sections other than left and right are skipped.
+            if name not in ("left", "right"):
+                continue
+            for block in i["blocks"]:
+                if block["name"] == "core":
+                    parse_core(block)
+                elif block["name"] == "plugin" and parse_plugin(block,
+                                                                plugin_idx):
+                    plugin_name = "{}_{}".format(plugin_idx,
+                                                 block["config"]["name"])
+                    if name == "left":
+                        left_plugins.append(plugin_name)
+                    else:
+                        right_plugins.append(plugin_name)
+                    plugins_to_source.append(block["config"]["name"])
+                    plugin_idx += 1
+
+    print_plugin_list("WISH_PLUGINS", left_plugins)
+    print_plugin_list("WISH_RIGHT_PLUGINS", right_plugins)
+    print_plugin_list("WISH_PLUGINS_SOURCE", plugins_to_source)
+
+
+# Python 2 patch
+# TODO: Write a better patch for Python 2
+try:
+    shlex.quote
+except AttributeError:
+    shlex.quote = lambda x: x
+
+if __name__ == "__main__":
+    main()

wish.sh

@@ -1,14 +1,44 @@
 #!/usr/bin/env bash
 
+# INTERNAL USE ONLY! Do not use this in plugins.
+function wish_print_right_prompt() {
+	local idx=0
+	for i in ${WISH_RPL[@]}; do
+		echo "\e[$(($COLUMNS - $i + 1))G${WISH_RIGHT_PS1[$idx]}"
+		((idx++))
+	done
+}
+
 function wish_init() {
+	# Find default config file if WISH_CONFIG_FILE is unset
+	if [[ ! -v WISH_CONFIG_FILE ]]; then
+		for path in "$XDG_CONFIG_HOME" "/usr/share" "$HOME/.config"; do
+			if [[ -f "$path/wish/config.gie" ]]; then
+				WISH_CONFIG_FILE="$path/wish/config.gie"
+				break
+			fi
+		done
+	fi
+	# Source config files
+	for path in "$XDG_CONFIG_HOME" "/usr/share" "$HOME/.config"; do
+		if [[ -f "$path/wish/wish.py" ]]; then
+			source <($path/wish/wish.py ${WISH_CONFIG_FILE[@]})
+			break
+		fi
+	done
 	# Source all plugins
+	# If WISH_CONFIG_FILE is not set, then assume that the user hasn't updated
+	# to a config file yet. Set WISH_PLUGINS_SOURCE=WISH_PLUGINS.
+	if [[ ! -v WISH_CONFIG_FILE ]]; then
+		WISH_PLUGINS_SOURCE=("${WISH_PLUGINS[@]}" "${WISH_RIGHT_PLUGINS[@]}")
+	fi
 	local plugin
 	local path
-	for plugin in ${WISH_PLUGINS[@]}; do
+	for plugin in ${WISH_PLUGINS_SOURCE[@]}; do
 		for path in "$XDG_CONFIG_HOME" "/usr/share" "$HOME/.config"; do
 			source "$path/wish/plugins/$plugin.sh" &> /dev/null && break
 		done
-		[[ $? -ne 0 ]] && echo "Plugin $i not found." >&2
+		[[ $? -ne 0 ]] && echo "Plugin $plugin not found." >&2
 	done
 
 	# Source theme
@@ -30,7 +60,7 @@ function wish_init() {
 	done
 
 	# Call plugins to set colors
-	for plugin in ${WISH_PLUGINS[@]}; do
+	for plugin in ${WISH_PLUGINS[@]} ${WISH_RIGHT_PLUGINS[@]}; do
 		eval wish_$(echo $plugin)_set_colors $prev
 	done
 }
@@ -59,7 +89,41 @@ function color_to_escape_code() {
 		fi
 	fi
 }
+# INTERNAL USE ONLY! Do not use this in plugins.
+# Usage: wish_append_left escape_codes text
+function wish_append_left() {
+	local text="$2"
+	local colors="$1"
+	local prompt_text="${text@P}"
+	if [[ $text == "\n" ]]; then
+		((WISH_LPLINE++))
+		WISH_LPL=(${WISH_LPL[@]} 0)
+		WISH_LEFT_PS1="$WISH_LEFT_PS1$colors$text"
+	else
+		if [[ $((${WISH_LPL[$WISH_LPLINE]} + ${#prompt_text})) -lt $COLUMNS ]]; then
+			WISH_LEFT_PS1="$WISH_LEFT_PS1$colors$text"
+			WISH_LPL[$WISH_LPLINE]=$((${WISH_LPL[$WISH_LPLINE]} + ${#prompt_text}))
+		fi
+	fi
+}
 
+# INTERNAL USE ONLY! Do not use this in plugins.
+# Usage: wish_append_right escape_codes text
+function wish_append_right() {
+	local text="$2"
+	local colors="$1"
+	local prompt_text="${text@P}"
+	if [[ $text == "\n" ]]; then
+		((WISH_RPLINE++))
+		WISH_RIGHT_PS1=("${WISH_RIGHT_PS1[@]}" "")
+		WISH_RPL=(${WISH_RPL[@]} 0)
+	elif [[ $((${WISH_LPL[$WISH_RPLINE]} + ${WISH_RPL[$WISH_RPLINE]} + ${#prompt_text})) -lt $COLUMNS ]]; then
+		WISH_RIGHT_PS1[$WISH_RPLINE]="${WISH_RIGHT_PS1[$WISH_RPLINE]}$colors$text"
+		WISH_RPL[$WISH_RPLINE]=$((${WISH_RPL[$WISH_RPLINE]} + ${#prompt_text}))
+	fi
+}
+
+# Public API
 # Usage: wish_append bg fg text
 #
 # Parameters:
@@ -76,23 +140,60 @@ function wish_append() {
 	local bg=$(color_to_escape_code 4 $bg_code)
 
 	if [[ $fg_code == -1 ]]; then
-		PS1="$PS1$fg${bg}$text"
+		case $WISH_STATE in
+			0)
+				wish_append_left "$fg$bg" "$text"
+				;;
+			1)
+				wish_append_right "$fg$bg" "$text"
+				;;
+		esac
 	else
-		PS1="$PS1$bg${fg}$text"
+		case $WISH_STATE in
+			0)
+				wish_append_left "$bg$fg" "$text"
+				;;
+			1)
+				wish_append_right "$bg$fg" "$text"
+				;;
+		esac
 	fi
 }
 
+# Public API
+# Usage: wish_remaining_chars
+# Parameters: None
+# Return Value: Capture stdout to get the remaining characters available in the
+# line.
+wish_remaining_chars() {
+	if [[ $WISH_STATE -eq 0 ]]; then
+		echo "$(( $COLUMNS - ${WISH_LPL[$WISH_LPLINE]} ))"
+	else
+		echo "$(( $COLUMNS - ${WISH_LPL[$WISH_RPLINE]} - ${WISH_RPL[$WISH_RPLINE]} ))"
+	fi
+}
 
 function wish_main() {
 	local prev=$?
+	# Set local IFS to avoid being affected by shell's IFS
+	local IFS=$' \n'
 	PS1=""
+	WISH_LEFT_PS1=""
+	WISH_RIGHT_PS1=("")
+	WISH_LPL=(0)
+	WISH_RPL=(0)
+	WISH_RPLINE=0
+	WISH_LPLINE=0
 	local i
+	# Set newline
 	if [[ $WISH_AUTONEWLINE != 0 ]]; then
 		echo -ne "\033[6n" ; read -s -d ';'; read -s -d R WISH_CURSOR_POSITION
 		if [[ $WISH_CURSOR_POSITION != "1" ]]; then
 			PS1="\n"
 		fi
 	fi
+	# Generate left prompt.
+	WISH_STATE=0  # 0 = left prompt, 1 = right prompt
 	for i in $(seq 0 $((${#WISH_PLUGINS[@]} - 1))); do
 		wish_${WISH_PLUGINS[i]}_main $prev
 		if [[ -v WISH_POWERLINE ]] && [[ $WISH_POWERLINE != 0 ]]; then
@@ -112,11 +213,32 @@ function wish_main() {
 				fi
 			fi
 		fi
-
-		if [[ $i -eq $((${#WISH_PLUGINS[@]} - 1)) ]]; then
-			PS1="$PS1\[\033[0;5;0m\]"
-		fi
 	done
+	# Generate Right prompt.
+	WISH_STATE=1
+	for i in $(seq 0 $((${#WISH_RIGHT_PLUGINS[@]} - 1))); do
+		if [[ -v WISH_POWERLINE ]] && [[ $WISH_POWERLINE != 0 ]]; then
+			if wish_${WISH_RIGHT_PLUGINS[$i]}_end $prev; then
+				if [[ $i == 0 ]]; then
+					local plugin=${WISH_RIGHT_PLUGINS[$i]}
+					local fg_name="WISH_${plugin^^}_BG"
+					wish_append -1 ${!fg_name} 
+				elif wish_${WISH_RIGHT_PLUGINS[$(($i - 1))]}_start $prev; then
+					local plugin=${WISH_RIGHT_PLUGINS[$i]}
+					local prev_plugin=${WISH_RIGHT_PLUGINS[$(($i-1))]}
+					local fg_name="WISH_${plugin^^}_BG"
+					local bg_name="WISH_${prev_plugin^^}_BG"
+					wish_append ${!bg_name} ${!fg_name} 
+				fi
+			fi
+		fi
+		wish_${WISH_RIGHT_PLUGINS[$i]}_main $prev
+	done
+	# Save cursor position, print right prompt, restore cursor position,
+	# print left prompt, reset terminal
+	PS1=$PS1"\[\e7"
+	PS1="$PS1$(wish_print_right_prompt)"
+	PS1="$PS1\e8\]$WISH_LEFT_PS1\[\033[0;5;0m\]"
 }
 
 wish_init