import json
import subprocess
import os
import sys
import datetime

import requests

from .blockchain import (
    get_latest_header
)

from .rpc.exceptions import (
    RPCError,
    JSONDecodeError,
    RequestsError,
    RequestsTimeoutError,
)

datetime_format = "%Y-%m-%d %H:%M:%S.%f"


class Typgpy(str):
    """
    Typography constants for pretty printing.

    Note that an ENDC is needed to mark the end of a 'highlighted' text segment.
    """
    HEADER = '\033[95m'
    OKBLUE = '\033[94m'
    OKGREEN = '\033[92m'
    WARNING = '\033[93m'
    FAIL = '\033[91m'
    ENDC = '\033[0m'
    BOLD = '\033[1m'
    UNDERLINE = '\033[4m'


def get_gopath():
    """
    :returns The go-path, assuming that go is installed.
    """
    return subprocess.check_output(["go", "env", "GOPATH"]).decode().strip()


def get_goversion():
    """
    :returns The go-version, assuming that go is installed.
    """
    return subprocess.check_output(["go", "version"]).decode().strip()


def is_active_shard(endpoint, delay_tolerance=60):
    """
    :param endpoint: The endpoint of the SHARD to check
    :param delay_tolerance: The time (in seconds) that the shard timestamp can be behind
    :return: If shard is active or not
    """
    try:
        curr_time = datetime.datetime.utcnow()
        latest_header = get_latest_header(endpoint=endpoint)
        time_str = latest_header["timestamp"][:19] + '.0'  # Fit time format
        timestamp = datetime.datetime.strptime(time_str, "%Y-%m-%d %H:%M:%S.%f").replace(tzinfo=None)
        time_delta = curr_time - timestamp
        return abs(time_delta.seconds) < delay_tolerance
    except (RPCError, JSONDecodeError, RequestsError, RequestsTimeoutError):
        return False


def get_bls_build_variables():
    """
    :returns The environment variables needed to build and/or run programs that
             use the Harmony BLS & MCL repo.
    :raises RuntimeError if openssl is not found.

    Note that this assumes that the BLS & MCL repo are in the appropriate directory
    as stated here: https://github.com/harmony-one/harmony/blob/master/README.md
    """
    variables = {}
    try:
        openssl_dir = subprocess.check_output(["which", "openssl"]).decode().strip().split("\n")[0]
    except (IndexError, subprocess.CalledProcessError) as e:
        raise RuntimeError("`openssl` not found") from e
    hmy_path = f"{get_gopath()}/src/github.com/harmony-one"
    bls_dir = f"{hmy_path}/bls"
    mcl_dir = f"{hmy_path}/mcl"
    assert os.path.exists(bls_dir), f"Harmony BLS repo not found at {bls_dir}"
    assert os.path.exists(mcl_dir), f"Harmony MCL repo not found at {mcl_dir}"
    if sys.platform.startswith("darwin"):
        variables["CGO_CFLAGS"] = f"-I{bls_dir}/include -I{mcl_dir}/include -I{openssl_dir}/include"
        variables["CGO_LDFLAGS"] = f"-L{bls_dir}/lib -L{openssl_dir}/lib"
        variables["LD_LIBRARY_PATH"] = f"{bls_dir}/lib:{mcl_dir}/lib:{openssl_dir}/lib"
        variables["DYLD_FALLBACK_LIBRARY_PATH"] = variables["LD_LIBRARY_PATH"]
    else:
        variables["CGO_CFLAGS"] = f"-I{bls_dir}/include -I{mcl_dir}/include"
        variables["CGO_LDFLAGS"] = f"-L{bls_dir}/lib"
        variables["LD_LIBRARY_PATH"] = f"{bls_dir}/lib:{mcl_dir}/lib"
    return variables


def json_load(string, **kwargs):
    """
    :param string: The JSON string to load
    :returns A dictionary loaded from a JSON string to a dictionary.
    :raises The exception caused by the load (if present).

    Note that this prints the failed input should an error arise.
    """
    try:
        return json.loads(string, **kwargs)
    except Exception as e:
        print(f"{Typgpy.FAIL}Could not parse input: '{string}'{Typgpy.ENDC}")
        raise e from e