import csv
import os
from shutil import copyfile
from time import sleep, time

import tts
from pydub import AudioSegment

SHORT_SILENCE = 500
LONG_SILENCE = 1000
SOUND_CACHE_FPATH = 'sound_cache.csv'
WORDS_FPATH = 'words.csv'

EXPONENTIAL_BACKOFF = 1.5
LANG_REGIONS = {
    'en': 'en-US',
    'de': 'de-de',
}

SOUND_CACHE = {}


def load_sound_cache():
    with open(SOUND_CACHE_FPATH, 'r') as csvFile:
        reader = csv.reader(csvFile)
        for line, row in enumerate(reader):
            wordid, lang, word = row[0], row[1], row[2]
            SOUND_CACHE[(word, lang)] = wordid


def get_cached_sound(word, lang):
    wordid = SOUND_CACHE.get((word, lang))
    return wordid


def generate_sound(word, lang, wordid):
    lang_region = LANG_REGIONS.get(lang)
    cached_wordid = get_cached_sound(word, lang)
    if cached_wordid:
        print("  Found in cache: {}".format(word))
        if cached_wordid != wordid:
            # TODO: this is duplicating space, but my brain is fried, should be mapping
            cached_filepath = os.path.join("sounds", "{}_{}.mp3".format(cached_wordid, lang))
            word_filepath = os.path.join("sounds", "{}_{}.mp3".format(wordid, lang))
            copyfile(cached_filepath, word_filepath)
    else:
        filename = "{}_{}.mp3".format(wordid, lang)
        filepath = os.path.join("sounds", filename)
        start = time()
        tts.gen_speech(word, lang_region, filepath)
        duration = time() - start
        print("  Generated ({} - {} s): {}".format(lang, duration, word))
        SOUND_CACHE[(word, lang)] = wordid
        with open(SOUND_CACHE_FPATH, 'a') as f:
            writer = csv.writer(f)
            writer.writerow([wordid, lang, word])


# umlauts: ä ö ü  Ä Ö
def gen_tts(wordids=None):
    if not wordids:
        wordids = list()
    with open(WORDS_FPATH, 'r') as csvFile:
        reader = csv.reader(csvFile)
        for row in reader:
            wordid, german, english = row[0], row[1], row[2]
            if wordid not in wordids:
                continue
            print("Generating {}: {}, {}".format(wordid, german, english))
            backoff, attempt = 1, 0
            while True:
                try:
                    for word, lang in [(german, 'de'), (english, 'en')]:
                        generate_sound(word, lang, wordid)
                except Exception as e:
                    backoff = backoff * EXPONENTIAL_BACKOFF
                    print("Sleeping for {}. Error: {}.".format(backoff, e))
                    if attempt % 3 == 0:
                        import pdb;
                        pdb.set_trace()
                    attempt += 1
                    sleep(backoff)
                    continue
                break


def filter_words(contains):
    wordids = []
    with open(WORDS_FPATH, 'r') as csvFile:
        reader = csv.reader(csvFile)
        for row in reader:
            if contains in row:
                wordids.append(row[0])
    return wordids


def concatenate(filename="lesson1", wordids=None):
    if not wordids:
        wordids = list()
    print("Concatenating {} sounds: {}".format(len(wordids), wordids))
    lessons = AudioSegment.silent(duration=1)
    silence = AudioSegment.silent(duration=SHORT_SILENCE)
    long_silence = AudioSegment.silent(duration=LONG_SILENCE)
    gen_tts(wordids=wordids)
    for wordid in wordids:
        start = time()
        sound_de = AudioSegment.from_mp3("sounds/{}_de.mp3".format(wordid))
        sound_en = AudioSegment.from_mp3("sounds/{}_en.mp3".format(wordid))
        lessons = lessons + sound_de + silence + sound_en + silence + sound_de + long_silence
        duration = time() - start
        print("Concatenated {} - {}s".format(wordid, duration))

    lessons.export(os.path.join("lessons", "{}.mp3".format(filename)), format="mp3")


if __name__ == "__main__":
    load_sound_cache()
    wordids = filter_words("lesson06")
    concatenate(filename="lesson06_half", wordids=wordids)