local M = {}

function M.config()
    require('bufferline').setup {
        options = {
            mode = "buffers", -- set to "tabs" to only show tabpages instead
            numbers = "none",
            close_command = "bdelete! %d", -- can be a string | function, see "Mouse actions"
            right_mouse_command = "bdelete! %d", -- can be a string | function, see "Mouse actions"
            left_mouse_command = "buffer %d", -- can be a string | function, see "Mouse actions"
            middle_mouse_command = nil, -- can be a string | function, see "Mouse actions"
            -- NOTE: this plugin is designed with this icon in mind,
            -- and so changing this is NOT recommended, this is intended
            -- as an escape hatch for people who cannot bear it for whatever reason
            indicator = {
                icon = '▎',
                style = 'icon'
            },
            buffer_close_icon = '',
            modified_icon = '●',
            close_icon = '',
            left_trunc_marker = '|',
            right_trunc_marker = '|',
            --- name_formatter can be used to change the buffer's label in the bufferline.
            --- Please note some names can/will break the
            --- bufferline so use this at your discretion knowing that it has
            --- some limitations that will *NOT* be fixed.
            name_formatter = function(buf) -- buf contains a "name", "path" and "bufnr"
                -- remove extension from markdown files for example
                if buf.name:match('%.md') then
                    return vim.fn.fnamemodify(buf.name, ':t:r')
                end
            end,
            max_name_length = 18,
            max_prefix_length = 15, -- prefix used when a buffer is de-duplicated
            tab_size = 18,
            diagnostics = "nvim_lsp",
            diagnostics_update_in_insert = false,
            diagnostics_indicator = function(count, level, diagnostics_dict, context)
                local s = " "
                for e, n in pairs(diagnostics_dict) do
                    local sym = e == "error" and " "
                        or (e == "warning" and " " or "")
                    s = s .. sym
                end
                return s
            end,
            -- NOTE: this will be called a lot so don't do any heavy processing here
            custom_filter = function(buf_number, buf_numbers)
                -- filter out filetypes you don't want to see
                if vim.bo[buf_number].filetype ~= "<i-dont-want-to-see-this>" then
                    return true
                end
                -- filter out by buffer name
                if vim.fn.bufname(buf_number) ~= "<buffer-name-I-dont-want>" then
                    return true
                end
                -- filter out based on arbitrary rules
                -- e.g. filter out vim wiki buffer from tabline in your work repo
                if vim.fn.getcwd() == "<work-repo>" and vim.bo[buf_number].filetype ~= "wiki" then
                    return true
                end
                -- filter out by it's index number in list (don't show first buffer)
                if buf_numbers[1] ~= buf_number then
                    return true
                end
            end,
            offsets = {
                { filetype = "bufferlist", text = "Explorer", text_align = "center" },
                { filetype = "filetree", text = "Explorer", text_align = "center" },
            },
            color_icons = true,
            show_buffer_icons = true,
            show_buffer_close_icons = true,
            show_close_icon = true,
            show_tab_indicators = true,
            persist_buffer_sort = true, -- whether or not custom sorted buffers should persist
            -- can also be a table containing 2 custom separators
            -- [focused and unfocused]. eg: { '|', '|' }
            separator_style = "thin",
            enforce_regular_tabs = false,
            always_show_bufferline = true,
            sort_by = 'id'
        }
    }
end

return M