# Handle limiter written by Buys de Barbanson, Hubrecht 2017
# This class allows for writing many files at the same time without the
# hassle of thinking about handle limitations.
import gzip
import time


class HandleLimiter(object):

    def __init__(self, maxHandles=32, pruneEvery=10000, compressionLevel=1):
        self.openHandles = {}
        self.seen = set()  # Which files have been opened before
        self.maxHandles = maxHandles
        self.pruneEvery = pruneEvery
        self.pruneIntervalCounter = 0
        self.compressionLevel = compressionLevel

    def write(self, path, string, method=None, forceAppend=False):  # 0= plain, 1:gzip

        if path not in self.openHandles:

            self.openHandles[path] = {}
            failedOpening = True
            while failedOpening:
                try:
                    if path in self.seen or forceAppend:
                        # Append when we already wrote to the file
                        if method == 1:
                            self.openHandles[path]['handle'] = gzip.open(
                                path, 'ab', self.compressionLevel)
                        else:
                            self.openHandles[path]['handle'] = open(path, 'a')
                    else:
                        # Open as new file when it is the first write
                        if method == 1:
                            self.openHandles[path]['handle'] = gzip.open(
                                path, 'wb', self.compressionLevel)
                        else:
                            self.openHandles[path]['handle'] = open(path, 'w')
                        # Remember that we accessed this file
                        self.seen.add(path)
                    failedOpening = False
                except Exception as e:
                    failedOpening = True
                    if len(self.openHandles) > 1:
                        self.close()
                    else:
                        # This is mayorly bad...
                        print(
                            'Failed writing to %s, even after closing all other open file-handles. Out of options...' %
                            path)
                        print(e)
                        # Raise the error to the parent method
                        raise
        if method == 0:
            self.openHandles[path]['handle'].write(string)
        else:
            self.openHandles[path]['handle'].write(bytes(string, 'UTF-8'))
        self.openHandles[path]['lastw'] = time.time()
        self.pruneIntervalCounter += 1
        if self.pruneIntervalCounter >= self.pruneEvery:
            self.prune()

    def prune(self):
        if len(self.openHandles) > self.maxHandles:
            toPrune = len(self.openHandles) - self.maxHandles
            pathsToPrune = sorted(
                self.openHandles.keys(), key=lambda path: (
                    self.openHandles[path]['lastw']))[
                :toPrune]  # ,reverse=True
            for path in pathsToPrune:
                if 'handle' in self.openHandles[path]:
                    try:
                        self.openHandles[path]['handle'].close()
                    except Exception as e:
                        pass

                self.openHandles.pop(path)
        self.pruneIntervalCounter = 0

    def close(self):

        k = self.openHandles.keys()
        destroyed = []
        for path in k:
            if 'handle' in self.openHandles[path]:
                try:
                    self.openHandles[path]['handle'].close()
                except BaseException:
                    pass
            else:
                print('Closed broken file handle for %s' % path)
            destroyed.append(path)
        for delete in destroyed:
            self.openHandles.pop(delete)