-- ------------------------------------------------------------
-- TERMINAL SYSTEM
-- ------------------------------------------------------------
local term_buf = nil

local function open_term_split()
	vim.cmd("botright vsplit")

	local win = vim.api.nvim_get_current_win()

	if term_buf and vim.api.nvim_buf_is_valid(term_buf) then
		vim.api.nvim_win_set_buf(win, term_buf)
	else
		vim.cmd("terminal")
		term_buf = vim.api.nvim_get_current_buf()
	end

	vim.api.nvim_win_set_width(win, math.floor(vim.o.columns * 0.37))
	vim.cmd("startinsert")
end

local function toggle_term()
	for _, win in ipairs(vim.api.nvim_list_wins()) do
		if vim.api.nvim_win_get_buf(win) == term_buf then
			vim.api.nvim_win_close(win, false)
			return
		end
	end

	open_term_split()
end

local function open_term_fullscreen()
	if term_buf and vim.api.nvim_buf_is_valid(term_buf) then
		vim.api.nvim_set_current_buf(term_buf)
	else
		vim.cmd("terminal")
		term_buf = vim.api.nvim_get_current_buf()
	end

	vim.cmd("startinsert")
end

local function prev_non_term_buf()
	local current = vim.api.nvim_get_current_buf()
	local buffers = vim.fn.getbufinfo({ buflisted = 1 })
	local candidates = {}

	for _, buffer in ipairs(buffers) do
		if buffer.bufnr ~= current and vim.bo[buffer.bufnr].buftype ~= "terminal" then
			table.insert(candidates, buffer)
		end
	end

	if #candidates == 0 then
		print("No previous non-terminal buffer")
		return
	end

	table.sort(candidates, function(a, b)
		return a.lastused > b.lastused
	end)

	vim.api.nvim_set_current_buf(candidates[1].bufnr)
end

function send(command)
	local terminal_visible = false

	for _, win in ipairs(vim.api.nvim_list_wins()) do
		if term_buf and vim.api.nvim_win_get_buf(win) == term_buf then
			terminal_visible = true
			break
		end
	end

	if not terminal_visible then
		open_term_split()
	end

	local job = vim.b[term_buf].terminal_job_id

	if job then
		vim.api.nvim_chan_send(job, command .. "\n")
	end
end
map("n", "<C-j>", toggle_term, { desc = "Toggle terminal split", })
map("n", "<C-o>", open_term_fullscreen, { desc = "Open terminal fullscreen", })
map("t", "<C-j>", toggle_term, { desc = "Toggle terminal split", })
map("t", "<C-o>", prev_non_term_buf, { desc = "Return to previous buffer", })