local global_options = {check_same = true}

local function stdio_formatter(cmd, options)
    local function apply(win, range, pos)
        local size = win.file.size
        local all = {start = 0, finish = size}
        if range == nil then range = all end
        local command = type(cmd) == 'function' and cmd(win, range, pos) or cmd
        local check_same = (options and options.check_same ~= nil) and
                               options.check_same or global_options.check_same
        local check = check_same == true or
                          (type(check_same) == 'number' and check_same >= size)
        local status, out, err = vis:pipe(win.file, all, command)
        if status ~= 0 then
            vis:message(err)
        elseif out == nil or out == '' then
            vis:info('No output from formatter')
        elseif not check or win.file:content(all) ~= out then
            local start, finish = range.start, range.finish
            win.file:delete(range)
            win.file:insert(start,
                            out:sub(start + 1, finish + (out:len() - size)))
        end
        return pos
    end
    return {
        apply = apply,
        options = options or {ranged = type(cmd) == 'function'}
    }
end

local function with_filename(win, option)
    if win.file.path then
        return option .. "'" .. win.file.path:gsub("'", "\\'") .. "'"
    else
        return ''
    end
end

local formatters = {}
formatters = {
    bash = stdio_formatter(function(win)
        return 'shfmt ' .. with_filename(win, '--filename ') .. ' -'
    end),
    csharp = stdio_formatter('dotnet csharpier'),
    go = stdio_formatter('gofmt'),
    lua = {
        pick = function(win)
            local _, out = vis:pipe(win.file,
                                    {start = 0, finish = win.file.size},
                                    'test -e .lua-format && echo luaformatter || echo stylua')
            return formatters[out:gsub('\n$', '')]
        end
    },
    luaformatter = stdio_formatter('lua-format'),
    markdown = stdio_formatter(function(win)
        if win.options and win.options.colorcolumn ~= 0 then
            return 'prettier --parser markdown --prose-wrap always ' ..
                       ('--print-width ' .. (win.options.colorcolumn - 1) .. ' ') ..
                       with_filename(win, '--stdin-filepath ')
        else
            return 'prettier --parser markdown ' ..
                       with_filename(win, '--stdin-filepath ')
        end
    end, {ranged = false}),
    powershell = stdio_formatter([[
    "$( (command -v powershell.exe || command -v pwsh) 2>/dev/null )" -c '
        Invoke-Formatter  -ScriptDefinition `
          ([IO.StreamReader]::new([Console]::OpenStandardInput()).ReadToEnd())
      ' | sed -e :a -e '/^[\r\n]*$/{$d;N;};/\n$/ba'
  ]]),
    rust = stdio_formatter('rustfmt'),
    stylua = stdio_formatter(function(win, range)
        if range and (range.start ~= 0 or range.finish ~= win.file.size) then
            return
                'stylua -s --range-start ' .. range.start .. ' --range-end ' ..
                    range.finish .. with_filename(win, ' --stdin-filepath ') ..
                    ' -'
        else
            return 'stylua -s ' .. with_filename(win, '--stdin-filepath ') ..
                       ' -'
        end
    end),
    text = stdio_formatter(function(win)
        if win.options and win.options.colorcolumn ~= 0 then
            return 'fmt -w ' .. (win.options.colorcolumn - 1)
        else
            return 'fmt'
        end
    end, {ranged = false})
}

local function getwinforfile(file)
    for win in vis:windows() do
        if win and win.file and win.file.path == file.path then
            return win
        end
    end
end

local function apply(file_or_keys, range, pos)
    local win =
        type(file_or_keys) ~= 'string' and getwinforfile(file_or_keys) or
            vis.win
    local ret = type(file_or_keys) ~= 'string' and function() return pos end or
                    function() return 0 end
    pos = pos or win.selection.pos
    local formatter = formatters[win.syntax]
    if formatter and formatter.pick then formatter = formatter.pick(win) end
    if formatter == nil then
        vis:info('No formatter for ' .. win.syntax)
        return ret()
    end
    if range ~= nil and not formatter.options.ranged and range.start ~= 0 and
        range.finish ~= win.file.size then
        vis:info('Formatter for ' .. win.syntax .. ' does not support ranges')
        return ret()
    end
    pos = formatter.apply(win, range, pos) or pos
    vis:insert('') -- redraw and friends don't work
    win.selection.pos = pos
    return ret()
end

return {
    formatters = formatters,
    options = global_options,
    apply = apply,
    stdio_formatter = stdio_formatter,
    with_filename = with_filename
}