"""
Loads all puppet files in environment, parse them, and store the
parsed data in the database.
"""

import hashlib
import json
import os
import os.path
import subprocess
import time
from sqlalchemy.sql import text

import threading
from threading import Lock, Thread
from queue import Queue


# import pyenc
from pyenc.model import db
from pyenc import model

from typing import Union, Generator


def with_lock(lock, proc):
    try:
        lock.acquire()
        proc()
    finally:
        lock.release()


def call(proc, *args):
    proc(*args)

path = Union[str, bytes]

def find(path: path, **kvs) -> list[bytes]:
    """Wrapper around find(1)."""
    cmdline = ['find', path]
    for key, value in kvs.items():
        cmdline.append(f'-{key}')
        cmdline.append(value)
    cmdline.append('-print0')

    cmd = subprocess.run(cmdline, capture_output=True, check=True)
    return (f for f in cmd.stdout.split(b'\0') if f)


class PuppetParseError(Exception):
    def __init__(self, code, msg):
        super().__init__()
        self.code = code
        self.msg = msg

    def __repr__(self):
        return f'PuppetParserError({self.code}, {self.msg})'

    def __str__(self):
        return repr(self)


def puppet_parse(file: path) -> bytes:
    with subprocess.Popen(
            ['puppet', 'parser', 'dump', '--format', 'json', file],
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE) as cmd:
        if cmd.retuncode and cmd.returncode != 0:
            raise PuppetParseError(cmd.returncode, cmd.stderr.read().decode('UTF-8'))

        json_data = cmd.stdout.read()

        if (value := cmd.wait()) != 0:
            raise PuppetParseError(value, cmd.stderr.read().decode('UTF-8'))

        return json_data


def parse_files(files: list[path]) -> Generator[model.PuppetFile]:
    for i, file in enumerate(files):
        try:
            stat = os.stat(file)

            last_modify = stat.st_mtime
            old_object = model.PuppetFile.query \
                              .where(model.PuppetFile.path == file) \
                              .first()

            if old_object and old_object.last_parse > last_modify:
                # file unchanged since our last parse, skip
                continue

            print(f'{i}/{len(files)}: {file}')

            if old_object:
                puppet_file = old_object
            else:
                puppet_file = model.PuppetFile(path=file)
            puppet_file.last_parse = time.time()
            # m.json = puppet_parse(file)

            yield puppet_file

        except PuppetParseError as err:
            # TODO cache error
            print('Error:', err)
            continue


def interpret_file(json_data: dict) -> list[str]:
    """Find all classes in json-representation of file."""
    top = json_data['^']
    if top[0] == 'class':
        tmp = top[1]['#']
        idx = tmp.index('name')
        return [tmp[idx + 1]]
        # print(tmp[idx + 1])
    elif top[0] == 'block':
        ret_value = []
        for element in top[1:]:
            if element['^'][0] == 'class':
                tmp = element['^'][1]['#']
                idx = tmp.index('name')
                ret_value.append(tmp[idx + 1])
        return ret_value
    else:
        return []



def enumerate_files(path_base, environment_name):
    path = os.path.join(path_base, environment.name)

    files = list(find(path, type='f', name='*.pp'))

    try:
        for puppet_file in parse_files(files):
            with open(puppet_file.path, 'rb') as f:
                checksum = hashlib.sha256(f.read()).hexdigest()
            # Returns puppet_file.path, relative to path_base
            puppet_file.path = os.path.relpath(puppet_file.path, path.encode('UTF-8'))
            # TODO does flask want the whole environment object?
            puppet_file.environment = environment.id
            puppet_file.checksum = checksum
            db.session.add(puppet_file)

    finally:
        db.session.commit()


def run(path_base: path, environment_name: str):

    ### Ensure that we have oru environment
    environment = model.PuppetEnvironment.query.where(model.PuppetEnvironment.name == environment_name).first()
    if not environment:
        environment = model.PuppetEnvironment(name=environment_name)
        db.session.add(environment)
        # TODO does this update the environment object
        db.session.commit()

    ### Identify all puppet files, and note the base of their content
    # enumerate_files(path_base, environment_name)


    ### Find all puppet files which we haven't parsed

    result = db.engine.execute(text("""
    SELECT 
        f.id,
        f.path, 
        f.last_parse, 
        f.checksum,
        env.name
    FROM puppet_file f
    LEFT OUTER JOIN puppet_file_content c
        ON f.checksum = c.checksum
    LEFT JOIN puppet_environment env
        ON f.environment = env.id
    WHERE c.json IS NULL
    """))

    # db_lock = Lock()
    threads = []
    q = Queue()
    for (id, path, last, checksum, environment) in result:
        print(environment, path)
        # return
        full_path = os.path.join(path_base.encode('UTF-8'), environment.encode('UTF-8'), path)

        with open(full_path, 'rb') as f:
            current_checksum = hashlib.sha256(f.read()).hexdigest()

        if current_checksum != checksum:
            print(f'Checksum changed for {environment}/{path}')
            # db.engine.execute(model.PuppetFile.delete().where(model.PuppetFile.id == id))
            continue

        thread = Thread(target=lambda checksum, full_path: (checksum, puppet_parse(full_path)),
                args=(checksum, full_path),
                name=f'{environment}/{path}')
        thread.start()
        threads.append(thread)

    try:
        # for thread in threads:
            # print(f'Waiting on {thread.name}')
            # thread.join()
            # print(f'{thread.name} joined')
        while not q.empty():
            print('Getting something from queue')
            (checksum, item) = q.get()
            print(checksum)
            pfc = model.PuppetFileContent(checksum=checksum, json=item)
            db.session.add(pfc)
            q.task_done()
    finally:
        db.session.commit()

    return

    try:
        for puppet_file in model.PuppetFile.query.all():
            try:
                class_names = interpret_file(json.loads(os.path.join(path, puppet_file.json)))
                for class_name in class_names:
                    db.session.add(model.PuppetClass(
                        class_name=class_name,
                        comes_from=puppet_file))
            except Exception as e:
                print(e)
                print(f'Failed: {puppet_file.path}')
    finally:
        db.session.commit()