--------------------------------------------------------------------------------
-- The MIT License
--
-- Copyright (c) 2009 Brian Schott
--
-- Permission is hereby granted, free of charge, to any person obtaining a copy
-- of this software and associated documentation files (the "Software"), to deal
-- in the Software without restriction, including without limitation the rights
-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-- copies of the Software, and to permit persons to whom the Software is
-- furnished to do so, subject to the following conditions:
--
-- The above copyright notice and this permission notice shall be included in
-- all copies or substantial portions of the Software.
--
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-- THE SOFTWARE.
--------------------------------------------------------------------------------


--------------------------------------------------------------------------------
-- Continues /* */ style comments
-- @return true if other functions should try to handle the event
-- @param block_start_chars The characters that define the start of a stream
--     comment
-- @param block_middle_chars The characters that define the middle of a stream
--     comment. This can be an empty string
-- @param block_end_chars The characters that define the end of a stream
--     comment
-- @param block_start_pattern The lua pattern that defines the start of a
--     stream comment. This is necessary because block_start_chars might
--     contain characters that need to be escaped
-- @param block_middle_pattern The lua pattern for the middle of a comment.
--     This can be an empty string
-- @param block_end_pattern The lua pattern for the end of a comment.
--------------------------------------------------------------------------------
function continue_block_comment(block_start_chars, block_middle_chars,
	block_end_chars, block_start_pattern, block_middle_pattern,
	block_end_pattern)
	-- Check with the lexer to see if we're actually in a comment. Otherwise
	-- this code will think that a multi-line multiplication is a C comment
	-- because of lines beginning with "*"
	if buffer:get_style_name(buffer.style_at[buffer.current_pos]) ~= "comment" then
		return true
	end

	local line_num = buffer:line_from_position(buffer.current_pos)
	local prev_line = buffer:get_line(line_num - 1)
	local curr_line = buffer:get_line(line_num + 1)
    local prev_is_end = prev_line:find(block_end_pattern.."%s*$")
    local prev_is_middle = prev_line:find("^%s*"..block_middle_pattern)
    local curr_is_middle = curr_line:find("^%s*"..block_middle_pattern)
    local prev_is_start = prev_line:find("^%s*"..block_start_pattern)
	if prev_is_end then
		buffer:null()
	elseif prev_is_middle or (curr_is_middle and prev_is_start) then
		local indent = buffer.line_indentation[line_num - 1]
		buffer:add_text(block_middle_chars)
		local aftermiddle = prev_line:match(
			"^%s*"..block_middle_pattern.."([ \t]+)")
		if aftermiddle ~= nil then
			buffer:add_text(aftermiddle)
		elseif prev_is_start then
			buffer:add_text(" ")
		end
        if prev_is_start then
            buffer.line_indentation[line_num] = indent + 1
        else
            buffer.line_indentation[line_num] = indent
        end
		buffer:line_end()
		return false
	elseif prev_is_start then
		local indent = buffer.line_indentation[line_num - 1]
		buffer:add_text(' '..block_middle_chars..' ')
		buffer:line_end()
		buffer:new_line()
		buffer:add_text(block_end_chars)
		buffer:line_up()
		buffer:line_end()
		return false
	else
		return true
	end
end


--------------------------------------------------------------------------------
-- Continues single-line comments
-- @return true if other functions should try to handle the event
-- @param line_pattern The lua pattern for the start of the comment
-- @param line_chars The characters for the start of the comment
--------------------------------------------------------------------------------
function continue_line_comment(line_chars, line_pattern)
	local line_num = buffer:line_from_position(buffer.current_pos)
	local prev_line = buffer:get_line(line_num - 1)
	if prev_line:find(line_pattern.."%s*$") then
		buffer:line_up()
		buffer:line_end()
		buffer:del_line_left()
		buffer:delete_back()
		buffer:line_down()
		return false
	elseif prev_line:find("^%s*"..line_pattern) then
		local indent = buffer.line_indentation[line_num - 1]
		buffer:add_text(line_chars)
		local aftercomment = prev_line:match(
			"^%s*"..line_pattern.."([ \t]+)")
		if aftercomment ~= nil then
			buffer:add_text(aftercomment)
		end
		buffer.line_indentation[line_num] = indent
		buffer:line_end()
		return false
	else
		return true
	end
end