nowopen/nowopen

#!/usr/bin/env lua
--
-- A simple program to display which places are currently open
-- 
-- Usage: nowopen [tag1 tag2...]
--
-- Establishments matching any of the specified tags (prefix matching is used)
-- and the amount of time till they close will be printed.
--
-- Business hours will be looked up in ~/.local/share/nowopen/businesshours or
-- ~/.businesshours and have the format:
--
-- Joe's Diner (restaurant, diner):
--     6am-1am
--     fri-sat: 6am-3am
--     sun: closed
--

local XDG_DATA_HOME = os.getenv("XDG_DATA_HOME") or "~/.local/share"
local f = io.open(XDG_DATA_HOME..'/nowopen/businesshours') or io.open('~/.businesshours')
if not f then
    print("Could not find config file")
    os.exit(1)
end
local place_text = f:read("*a")
f:close()

local raw_print = false
for i=#arg,1,-1 do
    if arg[i] == "-p" then
        raw_print = true
        table.remove(arg, i)
    elseif arg[i] == "-h" or arg[i] == "--help" then
        print([[
nowopen: show which businesses are now open.
Usage: nowopen [-p] [--help] [tags...]
    -p: Print plain text to stdout
    --help: display this message
    tags: if provided, only show businesses that match one of the given tags
]])
        os.exit(0)
    end
end

local lpeg = require('lpeg')
local re = require('re')

local today = os.date("*t")
local now = os.time(today)

local function hours(t)
    return math.floor(t/3600)
end
local function mins(t)
    return math.floor((t/60) % 60)
end
local function secs(t)
    return math.floor(t % 60)
end

local f = io.open('places.peg')
local dsl = re.compile(f:read('*a'), {tab="\t"})
f:close()
local places,err = dsl:match(place_text)
if err then
    print("Failed to parse config file:")
    print(place_text:sub(1,#place_text-#err).."\x1b[31;7m"..err.."\x1b[0m")
    os.exit(1)
end
    
local weekdays = {"sunday","monday","tuesday","wednesday","thursday","friday","saturday"}
local function get_weekday(str)
    for i,w in ipairs(weekdays) do
        if w:sub(1,#str) == str then return i end
    end
end

local options = {}
for i,place in ipairs(places) do
    if arg[1] then
        for _,request_tag in ipairs(arg) do
            for _,tag in ipairs(place.tags) do
                if tag:sub(1,#request_tag) == request_tag then goto carry_on end
            end
        end
        goto next_place
        ::carry_on::
    end
    local today_times
    for _,time in ipairs(place.times) do
        if get_weekday(time.from) <= today.wday
            and today.wday <= get_weekday(time.to or time.from) then
            today_times = time
        end
    end
    local function t(time)
        local hour24 = tonumber(time.hour)
        local minute = tonumber(time.minute or 0)
        if hour24 == 12 then
            if time.ampm == 'am' then hour24 = hour24 - 12 end
        else
            if time.ampm == 'pm' then hour24 = hour24 + 12 end
        end
        local t = os.time{hour=hour24, min=minute, year=today.year, month=today.month, day=today.day}
        while t < now do t = t + 24*60*60 end
        return t
    end
    if today_times and today_times.open then
        local until_open = t(today_times.open) - now
        local until_close = t(today_times.close) - now
        if until_close < until_open then
            table.insert(options, {name=place.name, until_close=until_close})
        end
    end
    ::next_place::
end

local rows, cols = 0, 0
    if not raw_print then
    local p = io.popen("tput cols")
    cols = tonumber(p:read("*a"))
    p:close()
    local p = io.popen("tput lines")
    rows = tonumber(p:read("*a"))
    p:close()
end

local output = raw_print and io.output() or io.popen("less -r", "w")

local function displaylen(str) return utf8.len((str:gsub("\x1b%[[0-9;]*m", ""))) end
local function center(str, n) return (" "):rep((n-displaylen(str))//2)..str..(" "):rep((n-displaylen(str))//2) end
local function lpad(str, n) return (" "):rep(n-displaylen(str))..str end

local lines = {}
local colors = setmetatable({[0]="\x1b[31;1m",[1]="\x1b[33;1m"}, {__index=function() return "\x1b[32;1m" end})
if #options == 0 and not raw_print then
    table.insert(lines, center("\x1b[1mSorry, nothing's open\x1b[0m", cols))
    table.insert(lines, "")
    table.insert(lines, center("¯\\_(ツ)_/¯", cols))
else
    table.sort(options, function(o1, o2) return o1.until_close < o2.until_close end)
    local max_line = 0
    for _,option in ipairs(options) do
        local line = ("%s:  %2s:%02d left"):format(
            option.name, hours(option.until_close), mins(option.until_close))
        if not raw_print then line = "    "..colors[hours(option.until_close)]..line.."\x1b[0m    " end
        if displaylen(line) > max_line then max_line = displaylen(line) end
        table.insert(lines, line)
    end
    if not raw_print then
        for i, line in ipairs(lines) do lines[i] = center(lpad(line, max_line), cols) end
        table.insert(lines, 1, center("\x1b[7m"..center("Open Now", max_line).."\x1b[0m", cols))
        table.insert(lines, 2, "")
    end
end

if not raw_print then output:write(("\n"):rep((rows-#lines)//2)) end
output:write(table.concat(lines, "\n"))
if not raw_print then output:write(("\n"):rep((rows-#lines)//2)) end
output:close()