-- MIT License
--
-- Copyright (c) 2021 hrsh7th
--
-- Permission is hereby granted, free of charge, to any person obtaining a copy
-- of this software and associated documentation files (the "Software"), to deal
-- in the Software without restriction, including without limitation the rights
-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-- copies of the Software, and to permit persons to whom the Software is
-- furnished to do so, subject to the following conditions:
--
-- The above copyright notice and this permission notice shall be included in all
-- copies or substantial portions of the Software.
--
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-- SOFTWARE.
local autocmd = {}

autocmd.events = {}

--- Subscribe autocmd
---@param event string
---@param callback function
---@return function
autocmd.subscribe = function(event, callback)
    autocmd.events[event] = autocmd.events[event] or {}
    table.insert(autocmd.events[event], callback)
    return function()
        for i, callback_ in ipairs(autocmd.events[event]) do
            if callback_ == callback then
                table.remove(autocmd.events[event], i)
                break
            end
        end
    end
end

--- Emit autocmd
---@param event string
autocmd.emit = function(event)
    autocmd.events[event] = autocmd.events[event] or {}
    for _, callback in ipairs(autocmd.events[event]) do
        callback()
    end
end

return autocmd
