---
-- Vis Lua plugin API standard library
-- @module vis

---
-- @type Vis

local ok, msg = pcall(function()
	vis.lexers = {}
	vis.lexers = require('lexer')
end)

if not ok then
	vis:info('WARNING: could not load lexer module, is lpeg installed?')
end

vis.events = {}

--- Map a new motion.
--
-- Sets up a mapping in normal, visual and operator pending mode.
-- The motion function will receive the @{Window} and an initial position
-- (in bytes from the start of the file) as argument and is expected to
-- return the resulting position.
-- @tparam string key the key to associate with the new mption
-- @tparam function motion the motion logic implemented as Lua function
-- @treturn bool whether the new motion could be installed
-- @usage
-- vis:motion_new("<C-l>", function(win, pos)
-- 	return pos+1
-- end)
--
vis.motion_new = function(vis, key, motion)
	local id = vis:motion_register(motion)
	if id < 0 then
		return false
	end
	local binding = function()
		vis:motion(id)
	end
	vis:map(vis.MODE_NORMAL, key, binding)
	vis:map(vis.MODE_VISUAL, key, binding)
	vis:map(vis.MODE_OPERATOR_PENDING, key, binding)
	return true
end

--- Map a new text object.
--
-- Sets up a mapping in visual and operator pending mode.
-- The text object function will receive the @{Window} and an initial
-- position(in bytes from the start of the file) as argument and is
-- expected to return the resulting range or `nil`.
-- @tparam string key the key associated with the new text object
-- @tparam function textobject the text object logic implemented as Lua function
-- @treturn bool whether the new text object could be installed
-- @usage
-- vis:textobject_new("<C-l>", function(win, pos)
-- 	return pos, pos+1
-- end)
--
vis.textobject_new = function(vis, key, textobject)
	local id = vis:textobject_register(textobject)
	if id < 0 then
		return false
	end
	local binding = function()
		vis:textobject(id)
	end
	vis:map(vis.MODE_VISUAL, key, binding)
	vis:map(vis.MODE_OPERATOR_PENDING, key, binding)
	return true
end

vis:textobject_new("ii", function(win, pos)

	if win.syntax == nil then
		return pos, pos
	end

	local before, after = pos - 4096, pos + 4096
	if before < 0 then
		before = 0
	end
	-- TODO make sure we start at a line boundary?

	local lexer = vis.lexers.load(win.syntax)
	local data = win.file:content(before, after - before)
	local tokens = lexer:lex(data)
	local cur = before
	-- print(before..", "..pos..", ".. after)

	for i = 1, #tokens, 2 do
		local name = tokens[i]
		local token_next = before + tokens[i+1] - 1
		-- print(name..": ["..cur..", "..token_next.."] pos: "..pos)
		if cur <= pos and pos < token_next then
			return cur, token_next
		end
		cur = token_next
	end

	return pos, pos
end)

vis.ftdetect = {}

vis.ftdetect.ignoresuffixes = {
	"~", ".orig", ".bak", ".old", ".new"
}

vis.ftdetect.filetypes = {
	actionscript = {
		ext = { ".as", ".asc" },
	},
	ada = {
		ext = { ".adb", ".ads" },
	},
	ansi_c = {
		ext = { ".c", ".C", ".h" },
	},
	antlr = {
		ext = { ".g", ".g4" },
	},
	apdl = {
		ext = { ".ans", ".inp", ".mac" },
	},
	apl = {
		ext = { ".apl" }
	},
	applescript = {
		ext = { ".applescript" },
	},
	asm = {
		ext = { ".asm", ".ASM", ".s", ".S" },
	},
	asp = {
		ext = { ".asa", ".asp", ".hta" },
	},
	autoit = {
		ext = { ".au3", ".a3x" },
	},
	awk = {
		ext = { ".awk" },
	},
	bash = {
		ext = { ".bash", ".csh", ".sh", ".zsh" },
		mime = { "text/x-shellscript" },
	},
	batch = {
		ext = { ".bat", ".cmd" },
	},
	bibtex = {
		ext = { ".bib" },
	},
	boo = {
		ext = { ".boo" },
	},
	caml = {
		ext = { ".caml", ".ml", ".mli", ".mll", ".mly" },
	},
	chuck = {
		ext = { ".ck" },
	},
	cmake = {
		ext = { ".cmake", ".cmake.in", ".ctest", ".ctest.in" },
	},
	coffeescript = {
		ext = { ".coffee" },
	},
	cpp = {
		ext = { ".cpp", ".cxx", ".c++", ".cc", ".hh", ".hpp", ".hxx", ".h++" },
	},
	crystal = {
		ext = { ".cr" },
	},
	csharp = {
		ext = { ".cs" },
	},
	css = {
		ext = { ".css" },
	},
	cuda = {
		ext = { ".cu", ".cuh" },
	},
	dart = {
		ext = { ".dart" },
	},
	desktop = {
		ext = { ".desktop" },
	},
	diff = {
		ext = { ".diff", ".patch" },
	},
	dmd = {
		ext = { ".d", ".di" },
	},
	dockerfile = {
		ext = { "Dockerfile" },
	},
	dot = {
		ext = { ".dot" },
	},
	dsv = {
		ext = { "group", "gshadow", "passwd", "shadow" },
	},
	eiffel = {
		ext = { ".e", ".eif" },
	},
	elixir = {
		ext = { ".ex", ".exs" },
	},
	erlang = {
		ext = { ".erl", ".hrl" },
	},
	faust = {
		ext = { ".dsp" },
	},
	fish = {
		ext = { ".fish" },
	},
	forth = {
		ext = { ".forth", ".frt", ".fs" },
	},
	fortran = {
		ext = { ".f", ".for", ".ftn", ".fpp", ".f77", ".f90", ".f95", ".f03", ".f08" },
	},
	fsharp = {
		ext = { ".fs" },
	},
	fstab = {
		ext = { "fstab" },
	},
	gap = {
		ext = { ".g", ".gd", ".gi", ".gap" },
	},
	gettext = {
		ext = { ".po", ".pot" },
	},
	gherkin = {
		ext = { ".feature" },
	},
	glsl = {
		ext = { ".glslf", ".glslv" },
	},
	gnuplot = {
		ext = { ".dem", ".plt" },
	},
	go = {
		ext = { ".go" },
	},
	groovy = {
		ext = { ".groovy", ".gvy" },
	},
	gtkrc = {
		ext = { ".gtkrc" },
	},
	haskell = {
		ext = { ".hs" },
	},
	html = {
		ext = { ".htm", ".html", ".shtm", ".shtml", ".xhtml" },
	},
	icon = {
		ext = { ".icn" },
	},
	idl = {
		ext = { ".idl", ".odl" },
	},
	inform = {
		ext = { ".inf", ".ni" },
	},
	ini = {
		ext = { ".cfg", ".cnf", ".inf", ".ini", ".reg" },
	},
	io_lang = {
		ext = { ".io" },
	},
	java = {
		ext = { ".bsh", ".java" },
	},
	javascript = {
		ext = { ".js", ".jsfl" },
	},
	json = {
		ext = { ".json" },
	},
	jsp = {
		ext = { ".jsp" },
	},
	latex = {
		ext = { ".bbl", ".dtx", ".ins", ".ltx", ".tex", ".sty" },
	},
	ledger = {
		ext = { ".ledger", ".journal" },
	},
	less = {
		ext = { ".less" },
	},
	lilypond = {
		ext = { ".lily", ".ly" },
	},
	lisp = {
		ext = { ".cl", ".el", ".lisp", ".lsp" },
	},
	litcoffee = {
		ext = { ".litcoffee" },
	},
	lua = {
		ext = { ".lua" },
	},
	makefile = {
		ext = { ".iface", ".mak", ".mk", "GNUmakefile", "makefile", "Makefile" },
	},
	man = {
		ext = { ".1", ".2", ".3", ".4", ".5", ".6", ".7", ".8", ".9", ".1x", ".2x", ".3x", ".4x", ".5x", ".6x", ".7x", ".8x", ".9x" },
	},
	markdown = {
		ext = { ".md", ".markdown" },
	},
	moonscript = {
		ext = { ".moon" },
	},
	nemerle = {
		ext = { ".n" },
	},
	networkd = {
		ext = { ".link", ".network", ".netdev" },
	},
	nim = {
		ext = { ".nim" },
	},
	nsis = {
		ext = { ".nsh", ".nsi", ".nsis" },
	},
	objective_c = {
		ext = { ".m", ".mm", ".objc" },
	},
	pascal = {
		ext = { ".dpk", ".dpr", ".p", ".pas" },
	},
	perl = {
		ext = { ".al", ".perl", ".pl", ".pm", ".pod" },
	},
	php = {
		ext = { ".inc", ".php", ".php3", ".php4", ".phtml" },
	},
	pico8 = {
		ext = { ".p8" },
	},
	pike = {
		ext = { ".pike", ".pmod" },
	},
	pkgbuild = {
		ext = { "PKGBUILD" },
	},
	powershell = {
		ext = { ".ps1" },
	},
	prolog = {
		ext = { ".prolog" },
	},
	props = {
		ext = { ".props", ".properties" },
	},
	protobuf = {
		ext = { ".proto" },
	},
	ps = {
		ext = { ".eps", ".ps" },
	},
	pure = {
		ext = { ".pure" },
	},
	python = {
		ext = { ".sc", ".py", ".pyw" },
	},
	rebol = {
		ext = { ".r", ".reb" },
	},
	rest = {
		ext = { ".rst" },
	},
	rexx = {
		ext = { ".orx", ".rex" },
	},
	rhtml = {
		ext = { ".erb", ".rhtml" },
	},
	rstats = {
		ext = { ".R", ".Rout", ".Rhistory", ".Rt", "Rout.save", "Rout.fail" },
	},
	ruby = {
		ext = { ".Rakefile", ".rake", ".rb", ".rbw" },
	},
	rust = {
		ext = { ".rs" },
	},
	sass = {
		ext = { ".sass", ".scss" },
	},
	scala = {
		ext = { ".scala" },
	},
	scheme = {
		ext = { ".sch", ".scm" },
	},
	smalltalk = {
		ext = { ".changes", ".st", ".sources" },
	},
	sml = {
		ext = { ".sml", ".fun", ".sig" },
	},
	snobol4 = {
		ext = { ".sno", ".SNO" },
	},
	sql= {
		ext = { ".ddl", ".sql" },
	},
	systemd = {
		ext = { ".automount", ".device", ".mount", ".path", ".scope", ".service", ".slice", ".socket", ".swap", ".target", ".timer" },
	},
	taskpaper = {
		ext = { ".taskpaper" },
	},
	tcl = {
		ext = { ".tcl", ".tk" },
	},
	texinfo = {
		ext = { ".texi" },
	},
	toml = {
		ext = { ".toml" },
	},
	vala = {
		ext = { ".vala" }
	},
	vb = {
		ext = { ".asa", ".bas", ".cls", ".ctl", ".dob", ".dsm", ".dsr", ".frm", ".pag", ".vb", ".vba", ".vbs" },
	},
	vcard = {
		ext = { ".vcf", ".vcard" },
	},
	verilog = {
		ext = { ".v", ".ver" },
	},
	vhdl = {
		ext = { ".vh", ".vhd", ".vhdl" },
	},
	wsf = {
		ext = { ".wsf" },
	},
	xml = {
		ext = { ".dtd", ".svg", ".xml", ".xsd", ".xsl", ".xslt", ".xul" },
	},
	xtend = {
		ext = {".xtend" },
	},
	yaml = {
		ext = { ".yaml" },
	},
}

vis.filetype_detect = function(win)
	local name = win.file.name
	-- remove ignored suffixes from filename
	local sanitizedfn = name
	if sanitizedfn ~= nil then
		sanitizedfn = sanitizedfn:gsub('^.*/', '')
		repeat
			local changed = false
			for _, pattern in pairs(vis.ftdetect.ignoresuffixes) do
				if #sanitizedfn >= #pattern then
					local s, e = sanitizedfn:find(pattern, -#pattern, true)
					if e == #sanitizedfn then
						sanitizedfn = sanitizedfn:sub(1, #sanitizedfn - #pattern)
						changed = true
					end
				end
			end
		until not changed
	end

	-- detect filetype by filename ending with a configured extension
	if sanitizedfn ~= nil then
		for lang, ft in pairs(vis.ftdetect.filetypes) do
			for _, pattern in pairs(ft.ext or {}) do
				if #sanitizedfn >= #pattern then
					local s, e = sanitizedfn:find(pattern, -#pattern, true)
					if e == #sanitizedfn then
						win.syntax = lang
						return
					end
				end
			end
		end
	end

	-- run file(1) to determine mime type
	if name ~= nil then
		local file = io.popen(string.format("file -bL --mime-type -- '%s'", name:gsub("'", "'\\''")))
		if file then
			local mime = file:read('*all')
			if mime then
				mime = mime:gsub('%s*$', '')
			end
			if mime and #mime > 0 then
				for lang, ft in pairs(vis.ftdetect.filetypes) do
					for _, ft_mime in pairs(ft.mime or {}) do
						if mime == ft_mime then
							win.syntax = lang
							return
						end
					end
				end
			end
		end
	end

	-- pass first few bytes of file to custom file type detector functions
	local file = win.file
	local data = file:content(0, 256)
	if data and #data > 0 then
		for lang, ft in pairs(vis.ftdetect.filetypes) do
			if type(ft.detect) == 'function' and ft.detect(file, data) then
				win.syntax = lang
				return
			end
		end
	end

	win.syntax = nil
end

vis.events.theme_change = function(name)
	if name ~= nil then
		local theme = 'themes/'..name
		package.loaded[theme] = nil
		require(theme)
	end

	if vis.lexers ~= nil then
		vis.lexers.lexers = {}
	end

	for win in vis:windows() do
		win.syntax = win.syntax;
	end
end

vis.events.win_syntax = function(win, name)
	local lexers = vis.lexers
	if not lexers.load then
		return false
	end

	win:style_define(win.STYLE_DEFAULT, lexers.STYLE_DEFAULT)
	win:style_define(win.STYLE_CURSOR, lexers.STYLE_CURSOR)
	win:style_define(win.STYLE_CURSOR_PRIMARY, lexers.STYLE_CURSOR_PRIMARY)
	win:style_define(win.STYLE_CURSOR_LINE, lexers.STYLE_CURSOR_LINE)
	win:style_define(win.STYLE_SELECTION, lexers.STYLE_SELECTION)
	win:style_define(win.STYLE_LINENUMBER, lexers.STYLE_LINENUMBER)
	win:style_define(win.STYLE_COLOR_COLUMN, lexers.STYLE_COLOR_COLUMN)

	if name == nil then
		return true
	end

	local lexer = lexers.load(name)
	if not lexer then
		return false
	end

	for token_name, id in pairs(lexer._TOKENSTYLES) do
		local style = lexers['STYLE_'..string.upper(token_name)] or lexer._EXTRASTYLES[token_name]
		win:style_define(id, style)
	end

	return true
end

vis.events.win_highlight = function(win, horizon_max)
	if win.syntax == nil or vis.lexers == nil then
		return
	end
	local lexer = vis.lexers.load(win.syntax)
	if lexer == nil then
		return
	end

	-- TODO: improve heuristic for initial style
	local viewport = win.viewport
	if not viewport then
		return
	end
	local horizon = viewport.start < horizon_max and viewport.start or horizon_max
	local view_start = viewport.start
	local lex_start = viewport.start - horizon
	local token_start = lex_start
	viewport.start = token_start
	local data = win.file:content(viewport)
	local token_styles = lexer._TOKENSTYLES
	local tokens = lexer:lex(data, 1)

	for i = 1, #tokens, 2 do
		local token_end = lex_start + tokens[i+1] - 1
		if token_end >= view_start then
			local name = tokens[i]
			local style = token_styles[name]
			if style ~= nil then
				win:style(style, token_start, token_end)
			end
		end
		token_start = token_end
	end
end

local modes = {
	[vis.MODE_NORMAL] = '',
	[vis.MODE_OPERATOR_PENDING] = '',
	[vis.MODE_VISUAL] = 'VISUAL',
	[vis.MODE_VISUAL_LINE] = 'VISUAL-LINE',
	[vis.MODE_INSERT] = 'INSERT',
	[vis.MODE_REPLACE] = 'REPLACE',
}

vis.events.win_status = function(win)
	local left_parts = {}
	local right_parts = {}
	local file = win.file
	local cursor = win.cursor

	local mode = modes[vis.mode]
	if mode ~= '' and vis.win == win then
		table.insert(left_parts, mode)
	end

	table.insert(left_parts, (file.name or '[No Name]') ..
		(file.modified and ' [+]' or '') .. (vis.recording and ' @' or ''))

	if file.newlines == "crlf" then
		table.insert(right_parts, "␍␊")
	end

	if #win.cursors > 1 then
		table.insert(right_parts, cursor.number..'/'..#win.cursors)
	end

	local size = file.size
	table.insert(right_parts, (size == 0 and "0" or math.ceil(cursor.pos/size*100)).."%")

	if not win.large then
		local col = cursor.col
		table.insert(right_parts, cursor.line..', '..col)
		if size > 33554432 or col > 65536 then
			win.large = true
		end
	end

	local left = ' ' .. table.concat(left_parts, " » ") .. ' '
	local right = ' ' .. table.concat(right_parts, " « ") .. ' '
	win:status(left, right);
end

vis.events.theme_change((not vis.ui or vis.ui.colors <= 16) and "default-16" or "default-256")