local config_file = ''
local config_dir = ''

---
-- Find config file and set global variables
--
-- @return string
local function find_config_file()
    if config_file ~= '' then
    	return config_file
    end

    local scandir = require('plenary.scandir').scan_dir
    local Path = require('plenary.path')

    local current_dir = Path:new('.')
    while config_file == '' do
    	local files = scandir(current_dir.filename, { depth = 1 })
	for _, file in ipairs(files) do
	    if string.find(file, 'rclone.conf') then
		config_file = file
		config_dir = current_dir.filename

		return config_file
	    end
	end

	--if current_dir:is_root() then
	if current_dir.filename == '/' then
	    return ''
	end

	current_dir = current_dir:parent()
    end
end

---
-- Get rclone config as JSON
-- and parse to table
--
-- @return string
local function get_config()
    local handle = io.popen('rclone config dump --config=' .. find_config_file(), 'r')
    local config = handle:read('*all');
    handle:close()

    return vim.fn.json_decode(config)
end

---
-- Get the desired remote config from the config file
--
-- @param remote string
--
-- @return string
-- @return table
local function get_remote_config(remote)
    local config = get_config()
    local target_remote = nil
    local target_config = nil

    if remote then
	if config[remote] then
	    target_remote = remote
	    target_config = config[remote]
	else
	    print("Couldn't find remote: " .. remote)
	end
    else
        local config_length = 0
	for _, _ in pairs(config) do
	    config_length = config_length + 1
        end

	if config_length == 1 then
	    for remote_name, remote_config in pairs(config) do
		target_remote = remote_name
		target_config = remote_config
	    end
	else
	    for remote_name, remote_config in pairs(config) do
		if remote_config.vim_rclone_default then
		    target_remote = remote_name
		    target_config = remote_config
		end
	    end
	end
    end

    if target_remote == nil then
    	print("Couldn't find suitable remote")
	-- TODO: check how to do error handling in lua/vim plugins
    end

    return target_remote, target_config
end

---
-- Call the 'rclone copy' command with config values
-- 'rclone copy $LOCAL_PATH $REMOTE:$REMOTE_PATH --config=find_config_file()'
--
-- @return any
local function copy()
    local Path = require('plenary.path')
    local remote, config = get_remote_config()

    local local_path = Path:new(config.vim_rclone_local_path)
    local_path._cwd = config_dir -- set cwd to config dir to resolve path correctly
    local_path = local_path:absolute()
    local_path = local_path:gsub('%./', '') -- remove wrongly kept ./ for relative paths

    local cmd =
	'rclone copy ' ..
	local_path .. ' ' ..
	remote .. ':' .. config.vim_rclone_remote_path ..
	' --config=' .. find_config_file()

    -- TODO: add configurable default exclude patterns
    local configurable_default_exclude_patterns = {'.git/'}
    for _, pattern in pairs(configurable_default_exclude_patterns) do
    	cmd = cmd .. ' --exclude=' .. pattern
    end

    -- add .gitignore patterns
    local gitignore = Path:new(local_path .. '/.gitignore')
    if gitignore:exists() then
        cmd = cmd .. ' --exclude-from=' .. gitignore.filename
    end

    -- add .rcloneignore patterns
    local rcloneignore = Path:new(local_path .. '/.rcloneignore')
    if rcloneignore:exists() then
    	cmd = cmd .. ' --exclude-from=' .. rcloneignore.filename
    end

    -- TODO: add --log-level=INFO --log-file=.local/share/nvim/rclone_nvim/rclone.log

    os.execute(cmd)
    print(cmd)
    print("Copied!")

    return config
end

return {
    copy = copy,
}