1 files changed, 292 insertions, 0 deletions
diff --git a/yazi/plugins/fs-usage.yazi/main.lua b/yazi/plugins/fs-usage.yazi/main.lua
new file mode 100644
index 0000000..dbcdef2
--- /dev/null
+++ b/yazi/plugins/fs-usage.yazi/main.lua
@@ -0,0 +1,292 @@
+--- @since 25.5.31
+
+local DEFAULT_OPTIONS = {
+	-- Can't reference Header.RIGHT etc. here (it hangs) so parent and align are strings
+	-- 2000 puts it to the right of the indicator, and leaves some room between
+	position = { parent = "Header", align = "RIGHT", order = 2000 },
+	format = "both",
+	bar = true,
+	warning_threshold = 90,
+	style_label = {
+		fg = th.status.progress_label:fg(),
+	},
+	style_normal = {
+		fg = th.status.progress_normal:fg(),
+		bg = th.status.progress_normal:bg(),
+	},
+	style_warning = {
+		fg = th.status.progress_error:fg(),
+		bg = th.status.progress_error:bg(),
+	},
+	padding = { open = "", close = "" },
+}
+
+---Deep copy and merge two tables, overwriting values from one table into another
+---@param from Table to take values from
+---@param to Table to merge into
+local function merge(into, from)
+	-- Handle nil inputs
+	into = into or {}
+	from = from or {}
+
+	local result = {}
+
+	-- Deep copy 'into' first
+	for k, v in pairs(into) do
+		if type(v) == "table" then
+			result[k] = merge({}, v)
+		else
+			result[k] = v
+		end
+	end
+
+	-- Merge
+	for k, v in pairs(from) do
+		if type(v) == "table" then
+			result[k] = merge(result[k], v)
+		else
+			result[k] = v
+		end
+	end
+
+	return result
+end
+
+---Merge label and bar styles into left/right styles for the bar
+---@param style_label Label style
+---@param style_bar Usage bar style
+local function build_styles(style_label, style_bar)
+	local style_right = ui.Style():fg(style_label.fg or style_bar.fg):bg(style_bar.bg) -- Label bg is ignored
+	if style_label.bold then
+		style_right = style_right:bold()
+	end
+	if style_label.italic then
+		style_right = style_right:italic()
+	end
+
+	-- Left style is the same as right, but with fg/bg reversed
+	--  (this is overridden by the label colour if set)
+	local style_left = ui.Style():patch(style_right):fg(style_label.fg or style_bar.bg):bg(style_bar.fg) -- Label bg is ignored
+
+	return style_left, style_right
+end
+
+---Parse source and usage from df output
+---@param stdout string df output
+local function process_df_output(stdout)
+	local source, usage = stdout:match(".*%s(%S+)%s+(%S+)")
+
+	-- Follow symlinks in source
+	if string.sub(source, 1, 1) == "/" then
+		source = Command("readlink"):arg({ "--silent", "--canonicalize", "--no-newline", source }):output().stdout
+	end
+
+	-- Assume usage is a valid percentage
+	-- Remove the percent and parse
+	usage = tonumber(string.sub(usage, 1, #usage - 1))
+
+	return source, usage
+end
+
+---Format text based on options
+---@param source Source
+---@param usage Usage
+---@param format Format
+local function format_text(source, usage, format)
+	local text = ""
+	if format == "both" then
+		text = string.format("%s: %d%%", source, usage)
+	elseif format == "name" then
+		text = string.format("%s", source)
+	elseif format == "usage" then
+		text = string.format("%d%%", usage)
+	end
+	return text
+end
+
+---Set new plugin state and redraw
+local set_state = ya.sync(function(st, source, usage, text, bar_len)
+	st.source = source
+	st.usage = usage
+	st.text = text
+	st.bar_len = bar_len
+
+	local render = ui.render or ya.render
+	render()
+end)
+
+---Get plugin state needed by entry
+local get_state = ya.sync(function(st)
+	return {
+		-- Persistent options
+		format = st.format,
+		bar = st.bar,
+		padding = st.padding,
+
+		-- Variables
+		source = st.source,
+		usage = st.usage,
+	}
+end)
+
+-- Called from init.lua
+---@param st State
+---@param opts Options
+local function setup(st, opts)
+	opts = merge(DEFAULT_OPTIONS, opts)
+
+	-- Allow unsetting some options
+	if opts.style_label.fg == "" then
+		opts.style_label.fg = nil
+	end
+	if opts.warning_threshold < 0 then
+		opts.warning_threshold = nil
+	end
+
+	-- Translate opts.position.parent option into a component reference
+	if opts.position.parent == "Header" then
+		opts.position.parent = Header
+	elseif opts.position.parent == "Status" then
+		opts.position.parent = Status
+	else
+		-- Just set it to nil, it's gonna cause errors anyway
+		opts.position.parent = nil
+	end
+
+	-- Set persistent options
+	local style_normal_left, style_normal_right = build_styles(opts.style_label, opts.style_normal)
+	local style_warning_left, style_warning_right = build_styles(opts.style_label, opts.style_warning)
+	st.style = {
+		normal = {
+			left = style_normal_left,
+			right = style_normal_right,
+			padding = {
+				left = ui.Style():fg(style_normal_left:bg()),
+				right = ui.Style():fg(style_normal_right:bg()),
+			},
+		},
+		warning = {
+			left = style_warning_left,
+			right = style_warning_right,
+			padding = {
+				left = ui.Style():fg(style_warning_left:bg()),
+				right = ui.Style():fg(style_warning_right:bg()),
+			},
+		},
+	}
+	st.format = opts.format
+	st.bar = opts.bar
+	st.warning_threshold = opts.warning_threshold
+	st.padding = opts.padding
+
+	-- Add the component to the parent
+	opts.position.parent:children_add(function(self)
+		-- No point showing anything if usage is nil
+		if not st.usage then
+			return
+		end
+
+		local style = (st.warning_threshold and st.usage >= st.warning_threshold) and st.style.warning
+			or st.style.normal
+
+		-- Apply styles to components based on the bar length, and ad them to the bar
+		local output = {}
+		local bar_len = st.bar_len
+		local components = {
+			{ text = st.padding.open, style = style.padding },
+			{ text = st.text, style = style },
+			{ text = st.padding.close, style = style.padding },
+		}
+		for _, component in ipairs(components) do
+			-- bar_len_bytes should point to the last byte that should be coloured by the usage bar
+			local bar_len_bytes
+			if bar_len <= 0 then
+				-- 1-indexed, so effectively no bar showing
+				bar_len_bytes = 0
+			elseif bar_len >= utf8.len(component.text) then
+				bar_len_bytes = #component.text
+			else
+				bar_len_bytes = utf8.offset(component.text, bar_len + 1) - 1
+			end
+
+			if bar_len_bytes > 0 then
+				table.insert(output, ui.Span(string.sub(component.text, 1, bar_len_bytes)):style(component.style.left))
+			end
+			if bar_len_bytes < #component.text then
+				table.insert(
+					output,
+					ui.Span(string.sub(component.text, bar_len_bytes + 1)):style(component.style.right)
+				)
+			end
+
+			bar_len = bar_len - utf8.len(component.text)
+		end
+
+		return ui.Line(output)
+	end, opts.position.order, opts.position.parent[opts.position.align])
+
+	---Pass cwd to the plugin for df
+	local function callback()
+		ya.emit("plugin", {
+			st._id,
+			ya.quote(tostring(cx.active.current.cwd), true),
+		})
+	end
+
+	-- Subscribe to events
+	ps.sub("cd", callback)
+	ps.sub("tab", callback)
+	ps.sub("delete", callback)
+	-- These are the only relevant events that actually work
+	-- Note: df might not immediately reflect usage changes
+	--  when deleting files
+end
+
+-- Called from ya.emit in the callback
+---@param job Job
+local function entry(_, job)
+	local cwd = job.args[1]
+
+	-- Don't set cwd directly for Command() here, it hangs for dirs without read perms
+	-- cwd is fine as an argument to df though
+	local output = Command("df"):arg({ "--output=source,pcent", tostring(cwd) }):output()
+
+	-- If df fails, hide the module
+	if not output.status.success then
+		set_state(nil, nil, nil, nil)
+		return
+	end
+
+	local source, usage = process_df_output(output.stdout)
+
+	-- If df read the filesystem but couldn't get a percentage, hide the module
+	-- if usage == nil then
+	if type(usage) ~= "number" then
+		set_state(nil, nil, nil, nil)
+		return
+	end
+
+	-- Get the plugin state (async) early since we know it will be used
+	local st = get_state()
+
+	-- If nothing has changed, don't bother updating
+	if source == st.source and usage == st.usage then
+		return
+	end
+
+	local text = format_text(source, usage, st.format)
+	local bar_len = 0 -- Start with no bar by default
+
+	-- Only calculate bar length if the bar will be shown
+	if st.bar then
+		local total_len = utf8.len(st.padding.open .. text .. st.padding.close)
+
+		-- Using ceil so the bar is only empty at 0%
+		-- Using len - 1 so the bar isn't full until 100%
+		bar_len = usage < 100 and math.ceil((total_len - 1) / 100 * usage) or total_len
+	end
+
+	set_state(source, usage, text, bar_len)
+end
+
+return { setup = setup, entry = entry }