ResourceWriter = require "./ResourceWriter"
LatexRunner = require "./LatexRunner"
OutputFileFinder = require "./OutputFileFinder"
Settings = require("settings-sharelatex")
Path = require "path"
logger = require "logger-sharelatex"
Metrics = require "./Metrics"
child_process = require "child_process"

module.exports = CompileManager =
	doCompile: (request, callback = (error, outputFiles) ->) ->
		compileDir = Path.join(Settings.path.compilesDir, request.project_id)

		timer = new Metrics.Timer("write-to-disk")
		logger.log project_id: request.project_id, "starting compile"
		ResourceWriter.syncResourcesToDisk request.project_id, request.resources, compileDir, (error) ->
			return callback(error) if error?
			logger.log project_id: request.project_id, time_taken: Date.now() - timer.start, "written files to disk"
			timer.done()

			timer = new Metrics.Timer("run-compile")
			Metrics.inc("compiles")
			LatexRunner.runLatex request.project_id, {
				directory: compileDir
				mainFile:  request.rootResourcePath
				compiler:  request.compiler
				timeout:   request.timeout
			}, (error) ->
				return callback(error) if error?
				logger.log project_id: request.project_id, time_taken: Date.now() - timer.start, "done compile"
				timer.done()

				OutputFileFinder.findOutputFiles request.resources, compileDir, (error, outputFiles) ->
					return callback(error) if error?
					callback null, outputFiles
	
	clearProject: (project_id, _callback = (error) ->) ->
		callback = (error) ->
			_callback(error)
			_callback = () ->

		compileDir = Path.join(Settings.path.compilesDir, project_id)
		proc = child_process.spawn "rm", ["-r", compileDir]

		proc.on "error", callback

		stderr = ""
		proc.stderr.on "data", (chunk) -> stderr += chunk.toString()

		proc.on "close", (code) ->
			if code == 0
				return callback(null)
			else
				return callback(new Error("rm -r #{compileDir} failed: #{stderr}"))

	syncFromCode: (project_id, file_name, line, column, callback = (error, pdfPositions) ->) ->
		# If LaTeX was run in a virtual environment, the file path that synctex expects
		# might not match the file path on the host. The .synctex.gz file however, will be accessed
		# wherever it is on the host.
		base_dir = Settings.path.synctexBaseDir(project_id)
		file_path = Path.join(base_dir, file_name)
		synctex_path = Path.join(Settings.path.compilesDir, project_id, "output.pdf")
		CompileManager._runSynctex ["code", synctex_path, file_path, line, column], (error, stdout) ->
			return callback(error) if error?
			logger.log project_id: project_id, file_name: file_name, line: line, column: column, stdout: stdout, "synctex code output"
			callback null, CompileManager._parseSynctexFromCodeOutput(stdout)

	syncFromPdf: (project_id, page, h, v, callback = (error, filePositions) ->) ->
		base_dir = Settings.path.synctexBaseDir(project_id)
		synctex_path = Path.join(Settings.path.compilesDir, project_id, "output.pdf")
		CompileManager._runSynctex ["pdf", synctex_path, page, h, v], (error, stdout) ->
			return callback(error) if error?
			logger.log project_id: project_id, page: page, h: h, v:v, stdout: stdout, "synctex pdf output"
			callback null, CompileManager._parseSynctexFromPdfOutput(stdout, base_dir)

	_runSynctex: (args, callback = (error, stdout) ->) ->
		bin_path = Path.resolve(__dirname + "/../../bin/synctex")
		proc = child_process.spawn bin_path, args
		proc.on "error", callback

		stdout = ""
		proc.stdout.on "data", (chunk) -> stdout += chunk.toString()
		stderr = ""
		proc.stderr.on "data", (chunk) -> stderr += chunk.toString()

		proc.on "close", (code) ->
			if code == 0
				return callback(null, stdout)
			else
				return callback(new Error("synctex failed: #{stderr}"))

	_parseSynctexFromCodeOutput: (output) ->
		results = []
		for line in output.split("\n")
			[node, page, h, v, width, height] = line.split("\t")
			if node == "NODE"
				results.push {
					page:   parseInt(page, 10)
					h:      parseFloat(h)
					v:      parseFloat(v)
					height: parseFloat(height)
					width:  parseFloat(width)
				}
		return results

	_parseSynctexFromPdfOutput: (output, base_dir) ->
		results = []
		for line in output.split("\n")
			[node, file_path, line, column] = line.split("\t")
			if node == "NODE"
				file = file_path.slice(base_dir.length + 1)
				results.push {
					file: file
					line: parseInt(line, 10)
					column: parseInt(column, 10)
				}
		return results