path: root/lua/inbox/view.lua

local config = require("inbox.config")
local indexers = require("inbox.indexers")
local utils = require("inbox.utils")

local M = {}

---@param path string
---@param buf_options table<string, any> | nil
---@return integer bufnr
function M.create_buffer(path, buf_options)
	local bufnr = vim.api.nvim_create_buf(true, false)

	for k, v in pairs(buf_options or {}) do
		vim.api.nvim_buf_set_option(bufnr, k, v)
	end

	local bufname = string.format("maildir://%s", path)

	vim.api.nvim_buf_set_name(bufnr, bufname)

	return bufnr
end

function M.render_buffer(bufnr)
	local maildir, id = utils.parse_scheme(bufnr)

	if maildir == nil then
		vim.notify(("Buffer is not a valid maildir buffer: %s"):format(bufnr), vim.log.levels.ERROR)
	elseif id ~= nil and id ~= "" then
		M.render_entry(bufnr, id)
	else
		M.render_inbox(bufnr, maildir)
	end
end

---@param bufnr integer
---@param start integer
---@param end_ integer
---@param strict_indexing boolean
---@param lines string[]?
---@param escape_ascii boolean?
function M.buf_set_lines(bufnr, start, end_, strict_indexing, lines, escape_ascii)
	local buf_writer
	if escape_ascii and pcall(require, "baleia") then
		local baleia = require("baleia").setup()
		buf_writer = baleia.buf_set_lines
	else
		buf_writer = vim.api.nvim_buf_set_lines
	end

	vim.bo[bufnr].modifiable = true
	buf_writer(bufnr, start, end_, strict_indexing, lines or {})
	vim.bo[bufnr].modifiable = false
	vim.bo[bufnr].modified = false
end

---@param maildir string
---@return integer bufnr
function M.initialize_inbox(maildir)
	local buf_options = vim.tbl_extend("keep", config.buf_options, {
		buftype = "acwrite",
		syntax = "inbox",
		filetype = "inbox",
	})

	local bufnr = M.create_buffer(maildir, buf_options)

	-- vim.api.nvim_clear_autocmds({ buffer = bufnr, group = "Inbox" })

	vim.keymap.set("n", "<Enter>", require("inbox").open_entry, { buffer = bufnr })

	M.render_inbox(bufnr, maildir)

	return bufnr
end

---@param bufnr integer
function M.render_inbox(bufnr, maildir)
	local indexer = indexers.get_indexer()
	indexer.index(maildir, function(ids, entries, signs)
		vim.b[bufnr].inbox_ids = ids
		local lines, highlights = utils.render_table(entries, config.columns)

		local winid = vim.api.nvim_get_current_win()
		for k, v in pairs(config.win_options) do
			vim.api.nvim_set_option_value(k, v, { scope = "local", win = winid })
		end

		M.buf_set_lines(bufnr, 0, -1, true, lines)
		utils.set_highlights(bufnr, highlights)
		utils.set_signs(bufnr, signs)

		vim.api.nvim_set_option_value(
			"winbar",
			utils.render_row({ "Flags", "Date", "From", "Subject" }, {
				vim.fn.getwininfo(winid)[1].textoff,
				unpack(config.columns),
			}),
			{ scope = "local", win = winid }
		)
	end)
end

---@param maildir string
---@param id string
---@param content_type string
---@return integer? bufnr
function M.initialize_entry(maildir, id, content_type)
	local bufname = ("%s:%s"):format(maildir, id)
	local bufnr = M.create_buffer(bufname, {
		syntax = "mail",
		filetype = "mail",
	})

	vim.api.nvim_clear_autocmds({ buffer = bufnr, group = require("inbox").augroup })

	vim.api.nvim_create_autocmd("BufDelete", {
		group = "Inbox",
		buffer = bufnr,
		callback = function()
			require("inbox").buffers[id] = nil
		end,
	})

	vim.keymap.set("n", "q", function()
		vim.api.nvim_buf_delete(bufnr, {})
	end, { buffer = bufnr })

	vim.keymap.set("n", "<C-h>", require("inbox").toggle_headers, { buffer = bufnr })
	vim.keymap.set("n", "<C-n>", function()
		local k
		if vim.b[bufnr].inbox_content_type then
			k = next(vim.b[bufnr].inbox_parts, vim.b[bufnr].inbox_content_type)
		else
			k = next(vim.b[bufnr].inbox_parts)
		end
		M.render_entry(bufnr, id, k)
	end, { buffer = bufnr })

	vim.b[bufnr].inbox_id = id
	vim.b[bufnr].header_filter = config.headers

	M.render_headers(bufnr, id)
	M.render_entry(bufnr, id, content_type)

	vim.api.nvim_create_autocmd({ "BufModifiedSet", "BufWinEnter" }, {
		group = "Inbox",
		buffer = bufnr,
		callback = function()
			for _, winid in pairs(vim.fn.win_findbuf(bufnr)) do
				local winbar = string.format(
					"%sPart: %s",
					string.rep(" ", vim.fn.getwininfo(winid)[1].textoff),
					vim.b[bufnr].inbox_content_type
				)

				vim.api.nvim_set_option_value("winbar", winbar, {
					scope = "local",
					win = winid,
				})
			end
		end,
	})

	return bufnr
end

function M.render_headers(bufnr, id)
	local indexer = indexers.get_indexer()
	local entry = indexer.get_entry(id)

	if entry == nil then
		return
	end

	local lines = {}

	local headers = {}
	if vim.b[bufnr].show_all_headers then
		headers = entry.headers
	else
		for _, name in pairs(config.headers) do
			if entry.headers[name] ~= nil then
				headers[name] = entry.headers[name]
			end
		end
	end

	for name, value in pairs(headers) do
		local i, line = next(value)
		table.insert(lines, ("%s: %s"):format(name, line))
		i, line = next(value, i)
		while i ~= nil do
			table.insert(lines, line)
			i, line = next(value, i)
		end
	end

	table.insert(lines, "")

	local cursor_pos = vim.fn.getpos(".")

	M.buf_set_lines(bufnr, 0, vim.b[bufnr].header_lines or 0, true, {})
	M.buf_set_lines(bufnr, 0, 0, true, lines)

	vim.b[bufnr].header_lines = #lines

	vim.fn.setpos(".", cursor_pos)
end

function M.render_entry(bufnr, id, content_type)
	local Job = require("plenary.job")
	local indexer = indexers.get_indexer()
	local entry = indexer.get_entry(id)

	if entry == nil then
		utils.error("Failed to get entry", { id = id })
		return
	end

	if content_type == nil then
		content_type = next(entry.parts)
	end

	local part = entry.parts[content_type]

	if part == nil then
		utils.error("Failed to find message part for entry", { id = id, ["content-type"] = content_type })
		return
	end

	vim.b[bufnr].inbox_parts = entry.parts
	vim.b[bufnr].inbox_content_type = content_type

	if vim.tbl_isempty(config.filters[content_type] or {}) then
		local lines = vim.split(part.content, "\n")
		M.buf_set_lines(bufnr, vim.b[bufnr].header_lines or 0, -1, true, lines)
	else
		local job

		for i, filter in pairs(config.filters[content_type] or {}) do
			for key, value in pairs(filter) do
				if type(value) == "function" then
					filter[key] = value(bufnr)
				else
					filter[key] = value
				end
			end

			local opts = {
				command = filter.command,
				args = filter.args,
			}

			if job == nil then
				opts.writer = part.content
			else
				opts.writer = job
			end

			if i == #config.filters[content_type] then
				opts.on_exit = vim.schedule_wrap(function(self)
					M.buf_set_lines(bufnr, vim.b[bufnr].header_lines or 0, -1, true, self:result(), true)
				end)
			end

			job = Job:new(opts)
		end

		job:start()
	end
end

return M