local fn = vim.fn
local api = vim.api

-- possible values are 'arrow' | 'rounded' | 'blank'
local active_sep = 'blank'

-- change them if you want to different separator
local separators = {
	arrow = { '', '' },
	rounded = { '', '' },
	blank = { '', '' },
}

-- highlight groups
local colors = {
	active        = '%#StatusLine#',
	inactive      = '%#StatuslineNC#',
	mode          = '%#Mode#',
	mode_alt      = '%#ModeAlt#',
	git           = '%#Git#',
	git_alt       = '%#GitAlt#',
	filetype      = '%#Filetype#',
	filetype_alt  = '%#FiletypeAlt#',
	line_col      = '%#LineCol#',
	line_col_alt  = '%#LineColAlt#',
}

local trunc_width = setmetatable({
	mode       = 80,
	git_status = 90,
	filename   = 140,
	line_col   = 60,
}, {
	__index = function()
		return 80
	end
})

local is_truncated = function(_, width)
	local current_width = api.nvim_win_get_width(0)
	return current_width < width
end

--local modes = setmetatable({
	--['n']  = {'Normal', 'N'};
	--['no'] = {'N·Pending', 'N·P'} ;
	--['v']  = {'Visual', 'V' };
	--['V']  = {'V·Line', 'V·L' };
	--[''] = {'V·Block', 'V·B'}; -- this is not ^V, but it's , they're different
	--['s']  = {'Select', 'S'};
	--['S']  = {'S·Line', 'S·L'};
	--[''] = {'S·Block', 'S·B'}; -- same with this one, it's not ^S but it's 
	--['i']  = {'Insert', 'I'};
	--['ic'] = {'Insert', 'I'};
	--['R']  = {'Replace', 'R'};
	--['Rv'] = {'V·Replace', 'V·R'};
	--['c']  = {'Command', 'C'};
	--['cv'] = {'Vim·Ex ', 'V·E'};
	--['ce'] = {'Ex ', 'E'};
	--['r']  = {'Prompt ', 'P'};
	--['rm'] = {'More ', 'M'};
	--['r?'] = {'Confirm ', 'C'};
	--['!']  = {'Shell ', 'S'};
	--['t']  = {'Terminal ', 'T'};
--}, {
	--__index = function()
		--return {'Unknown', 'U'} -- handle edge cases
	--end
--})

local get_current_mode = function()
	return string.format('[%s]', api.nvim_get_mode().mode )
end

local get_git_status = function()
	-- use fallback because it doesn't set this variable on the initial `BufEnter`
	local signs = vim.b.gitsigns_status_dict or {head = '', added = 0, changed = 0, removed = 0}
	local is_head_empty = signs.head ~= ''

	if is_truncated(trunc_width.git_status) then
		return is_head_empty and string.format('  %s ', signs.head or '') or ''
	end

	return is_head_empty and string.format(
	' +%s ~%s -%s |  %s ',
	signs.added, signs.changed, signs.removed, signs.head
	) or ''
end

local get_filename = function()
	--if is_truncated(trunc_width.filename) then return "%<%f" end
	return "%<%F"
end

local get_filetype = function()
	local filetype = vim.bo.filetype
	if filetype == '' then
		return ''
	end
	return string.format('%s', filetype):lower()
end

local get_line_col = function()
	return '%l:%c'
end

Statusline = {}

Statusline.active = function()
	local navic = require('nvim-navic')

	--local mode = colors.mode .. self:get_current_mode()
	--local mode_alt = colors.mode_alt .. self.separators[active_sep][1]
	--local git = colors.git .. self:get_git_status()
	--local git_alt = colors.git_alt .. self.separators[active_sep][1]
	--local filename = colors.inactive .. self:get_filename() .. colors.git_alt
	--local location = ""
	--if navic.is_available() then
	--location = navic.get_location()
	--end
	--local filetype_alt = colors.filetype_alt .. self.separators[active_sep][2]
	--local filetype = colors.filetype .. self:get_filetype()
	--local line_col = colors.line_col .. self:get_line_col()
	--local line_col_alt = colors.line_col_alt .. self.separators[active_sep][2]

	local mode = get_current_mode()
	--local git = get_git_status()
	local filename = get_filename() .. colors.git_alt
	local location = ""
	if navic.is_available() then
		location = navic.get_location()
	end
	local filetype = get_filetype()
	local line_col = get_line_col()

	return table.concat({
		mode, " ", filename, " ", "%m%r%q", " ", filetype,
		"%=",
		location, " ", line_col, " "
	})
end

Statusline.inactive = function()
	return colors.inactive .. '%F'
end

Statusline.set_explorer = function()
	local title = colors.mode .. '   '
	local title_alt = colors.mode_alt .. Statusline.separators[active_sep][2]

	return table.concat({ colors.active, title, title_alt })
end

--Statusline = setmetatable(M, {
	--__call = function(statusline, mode)
		--if mode == "active" then return statusline:set_active() end
		--if mode == "inactive" then return statusline:set_inactive() end
		--if mode == "explorer" then return statusline:set_explorer() end
	--end
--})

local augroup = api.nvim_create_augroup('Statusline', { clear = true})
api.nvim_create_autocmd({"WinEnter", "BufEnter"}, {
	command = "setlocal statusline=%!v:lua.Statusline.active()",
	group = augroup
})
api.nvim_create_autocmd({"WinLeave", "BufLeave"}, {
	command = "setlocal statusline=%!v:lua.Statusline.inactive()",
	group = augroup
})

----[[
--  NOTE: I don't use this since the statusline already has
--  so much stuff going on. Feel free to use it!
--  credit: https://github.com/nvim-lua/lsp-status.nvim
--
--  I now use `tabline` to display these errors, go to `_bufferline.lua` if you
--  want to check that out
----]]
-- Statusline.get_lsp_diagnostic = function(self)
--   local result = {}
--   local levels = {
--     errors = 'Error',
--     warnings = 'Warning',
--     info = 'Information',
--     hints = 'Hint'
--   }

--   for k, level in pairs(levels) do
--     result[k] = vim.lsp.diagnostic.get_count(0, level)
--   end

--   if self:is_truncated(120) then
--     return ''
--   else
--     return string.format(
--       "| :%s :%s :%s :%s ",
--       result['errors'] or 0, result['warnings'] or 0,
--       result['info'] or 0, result['hints'] or 0
--     )
--   end
-- end