# coding: utf-8

import copy
import os
import time
import logging
from abc import ABCMeta
from functools import partial

import numpy as np

import tables
from tables import HDF5ExtError, NoSuchNodeError
from tables.registry import class_name_dict

from utils.params import default_params, load_params
from utils.units import U
import sys
import traceback


class Rule:
    def __init__(
        self,
        process,
        description="",
        group="",
        dependencies=[],
        kind="snapshot",
        unit=U.none,
        name="",
    ):
        self.name = name
        self.process_fn = process
        self.dependencies = dependencies
        self.group = group
        self.description = description
        self.unit = unit
        self.kind = kind

    def process(self, arg, **kwargs):
        if arg is not None:
            return self.process_fn(arg, **kwargs)
        else:
            return self.process_fn(**kwargs)


class BaseProcessor:
    """
    Base class for processors, should not be instanciated
    """

    __metaclass__ = ABCMeta

    log_id = "base"
    rules = {}
    solve_self_dep = True

    def __init__(self, path, path_out=".", params=None, tag=None):
        if params is None:
            self.params = default_params()
        elif type(params) == str:
            self.params = load_params(params)
        else:
            self.params = copy.deepcopy(params)

        # Determining output directory
        if path_out is None:
            self.path_out = path
        else:
            self.path_out = path_out

        if tag is not None:
            self.params.out.tag = tag

        # Initialize logger
        self.logger = logging.getLogger(self.log_id)
        self.logger.propagate = False
        logging_format = "%(levelname)s | %(asctime)s | %(name)s.%(funcName)s:%(lineno)d | %(message)s"
        formatter = logging.Formatter(logging_format, datefmt="%H:%M:%S")

        if not self.logger.hasHandlers():
            stream = logging.StreamHandler(sys.stdout)
            stream.setFormatter(formatter)
            self.logger.addHandler(stream)

        if len(self.params.process.logfile) > 0:
            fileHandler = logging.FileHandler(self.params.process.logfile)
            fileHandler.setFormatter(formatter)
            self.logger.addHandler(fileHandler)
        if self.params.process.verbose:
            self.logger.setLevel(logging.DEBUG)
        else:
            self.logger.setLevel(logging.WARNING)

        for handler in self.logger.handlers:
            handler.setFormatter(formatter)

    def process(
        self,
        to_process,
        arg=None,
        overwrite=False,
        overwrite_dep=False,
        skip_dep=False,
        select=None,
        **kwargs,
    ):
        self.overwrite_dep = overwrite_dep
        self.just_done = []
        """ Process the rule 'to_process'

        Parameters
        ----------
        to_process : str of Rule
            name of the rule to process or Rule object with nonempty rule.name
        arg : optional
            argument to give to the rule
        overwrite : bool, optional
            Force redo if already done
        overwrite_dep : bool, optional
            Force redoing of the dependencies even if already done
        skip_dep : bool, optional
            Skip the dependency checks (assume they are already done)
        select : dict, optional
           Select object (see RunSelector) to only select some run/snapshot
        """

        if to_process in self.rules:
            rule = self.rules[to_process]
            return self._solve_and_process_rule(
                to_process, rule, arg, overwrite, skip_dep, select, **kwargs
            )
        elif isinstance(to_process, Rule):
            rule = to_process
            return self._solve_and_process_rule(
                rule.name, rule, arg, overwrite, skip_dep, select, **kwargs
            )
        else:
            self.logger.error(
                "{} is unknown, allowed rules are {}".format(
                    to_process, self.rules.keys()
                )
            )

    def _solve_and_process_rule(
        self, name, rule, arg, overwrite=False, skip_dep=False, select=None, **kwargs
    ):
        """Resolve dependencies and proceed in the processing of a rule

        Parameters
        ----------
        name : str
            name of the rule
        rule : Rule
            rule object
        overwrite : bool, optional
            Force redo if already done
        skip_dep : bool, optional
            Skip the dependency checks (assume they are already done)
        select : dict, optional
        Select object (see RunSelector) to only select some run/snapshot

        Returns
        -------
        The outbut of self._process_rule
        """
        updated = False
        if not skip_dep:
            updated = self._solve_dependencies(name, rule, arg, overwrite, select)
        overwrite_rule = overwrite or updated
        return self._process_rule(name, rule, arg, overwrite_rule, select, **kwargs)

    def _solve_dependencies(self, name, rule, arg, overwrite=False, select=None):

        self.done_before_dep = len(self.just_done)

        # Solve dependencies
        for dep in rule.dependencies:
            # get arguments
            try:
                dep_arg = rule.dependencies[dep]
            except (TypeError, KeyError):
                dep_arg = arg

            if dep_arg == "__parent__":
                dep_arg = arg

            # Whether the processor solves its own dependencies or it gives
            # it to a child processor
            if self.solve_self_dep and dep in self.rules:
                rule_dep = self.rules[dep]
                self._solve_and_process_rule(
                    dep, rule_dep, dep_arg, self.overwrite_dep, select
                )
            else:
                self._not_self_dep(name, dep, dep_arg, self.overwrite_dep, select)

        # Whether dependencies where updated
        return len(self.just_done) > self.done_before_dep

    def _not_self_dep(self, name, dep, dep_arg, overwrite, select=None):
        self.logger.error("Dependency {} for {} is unknown".format(dep, name))

    def _needs_computation(self, overwrite, name_full):
        return overwrite

    def _process_rule(self, name, rule, arg, overwrite=False, select=None, **kwargs):
        if arg is not None and not isinstance(arg, BaseProcessor):
            name_full = rule.group + "/" + name + "_" + str(arg)
        else:
            name_full = rule.group + "/" + name

        if name_full not in self.just_done:
            if self._needs_computation(overwrite, name_full):
                self.logger.debug("Processing {}".format(name_full))
                data = rule.process(arg, **kwargs)
                self._save_data(name_full, data, rule.description, rule.unit)
                self.logger.info("Data for {} computed".format(name_full))
                self.just_done.append(name_full)
                return data
            else:
                self.logger.info("Data for {} is already computed.".format(name_full))

    def def_rules(self):
        for rule in self.rules:
            func = partial(self.process, rule)
            func.__doc__ = self.rules[rule].description
            setattr(self, rule, func)


class HDF5Container(BaseProcessor):

    filename = ""
    save = None
    opened = False

    def open(self):
        if not self.opened:
            try:
                self.save = tables.open_file(self.filename, mode="a")
            except HDF5ExtError:
                # Wait a bit if the lock was not still released
                time.sleep(3)
                self.save = tables.open_file(self.filename, mode="a")
            self.opened = True

    def close(self):
        if self.opened:
            self.save.close()
            self.opened = False

    def _needs_computation(self, overwrite, name_full):
        return overwrite or not (name_full in self.save)

    def _process_rule(self, name, rule, arg, overwrite, select, **kwargs):
        self.open()
        try:
            super(HDF5Container, self)._process_rule(
                name, rule, arg, overwrite, select, **kwargs
            )
        except Exception as e:
            if self.params.process.allow_error:
                traceback_lines = traceback.format_exc().splitlines()
                for line in traceback_lines:
                    if line != traceback_lines[-1]:
                        self.logger.error(line)
                self.logger.error(f"{repr(e)}")
                pass
            else:
                raise
        finally:
            self.close()

    def get_value(self, node_name, unit=None, unit_old=None):
        open_before = self.opened
        if not open_before:
            self.open()
        try:
            node = self.save.get_node(node_name)

            if "unit" in node._v_attrs:
                unit_old = node._v_attrs.unit

            if node._v_attrs.CLASS == "GROUP":
                value = {}
                for child_name in node._v_children:
                    value[child_name] = self.get_value(
                        node_name + "/" + child_name, unit, unit_old
                    )
            else:
                value = node.read()
                if isinstance(unit, dict):
                    name = os.path.basename(node_name)
                    if name in unit:
                        unit = unit[name]
                    else:
                        unit = None
                if not (unit is None or unit_old is None or unit_old == U.none):
                    value = value * unit_old.express(unit)
        except NoSuchNodeError:
            self.logger.error(
                f"The value {node_name} is node available", stack_info=True
            )
            raise
        finally:
            if not open_before:
                self.close()
        return value

    def set_value(self, node_name, data, description, unit):
        open_before = self.opened
        if not open_before:
            self.open()
        try:
            self._save_data(node_name, data, description, unit)
        finally:
            if not open_before:
                self.close()

    def get_attribute(self, node_name, attr_name):
        open_before = self.opened
        if not open_before:
            self.open()
        try:
            node = self.save.get_node(node_name)
            attr = node._v_attrs[attr_name]
        finally:
            if not open_before:
                self.close()
        return attr

    def set_attribute(self, node_name, attr_name, attr_value):
        open_before = self.opened
        if not open_before:
            self.open()
        try:
            node = self.save.get_node(node_name)
            node._v_attrs[attr_name] = attr_value
        finally:
            if not open_before:
                self.close()

    def _get_units(self, unit, data=None):
        """
        Get real units from info files
        unit is either:
        1. An instance of U.Unit (pymses unit class)
        2. A string beginning by "unit_", referring to a code unit,
           available in self.info
        3. A dict {unit1 : exp1, unit2: exp2, ...} with unitX as 2.
           and expX a float, referring to the compound unit
           unit1**exp1 * unit2**exp2
        4. A dict {key: unit, ...} where key is a field name (eg. 'time', or 'mass')
           and unit the corresponding unit (on one on the above format)

        Returns:
        1-3. : a U.Unit instance
        4.   : a dict {key: unit, ...} with same key as input and unit being U.Unit instances
        """
        if isinstance(unit, U.Unit):
            return unit
        if isinstance(unit, str) and unit[:5] == "unit_":
            res = self.info[unit]
            if unit == "unit_length":
                res = res / self.info["boxlen"]
            return res
        if list(unit)[0][:5] == "unit_":
            new_unit = U.none
            for base_unit_str in unit:
                expo = unit[base_unit_str]
                base_unit = self._get_units(base_unit_str)
                new_unit = new_unit * base_unit**expo
            return new_unit
        if (data is not None) and isinstance(data, dict) and list(unit)[0] in data:
            for key in unit:
                unit[key] = self._get_units(unit[key])
            return unit

        else:
            raise ValueError("Invalid unit")

    def _save_data(self, name_full, data, description, unit):
        """
        Save data in the HDF5 structure, overwrite if necessary
        """

        unit = self._get_units(unit, data=data)

        if name_full in self.save:
            self.save.remove_node(name_full, recursive=True)

        attrs = None
        if isinstance(data, tuple):
            attrs = data[1]
            data = data[0]

        if isinstance(data, dict):
            if type(description) == str:
                self.save.create_group(
                    os.path.dirname(name_full),
                    os.path.basename(name_full),
                    description,
                    createparents=True,
                )
            else:
                self.save.create_group(
                    os.path.dirname(name_full),
                    os.path.basename(name_full),
                    "",
                    createparents=True,
                )

            if not isinstance(unit, dict):
                self.save.get_node(name_full)._v_attrs.unit = unit

            for key in data:
                key = str(key)
                if isinstance(description, dict):
                    if isinstance(unit, dict):
                        self._save_data(
                            name_full + "/" + key,
                            data[key],
                            description[key],
                            unit[key],
                        )
                    else:
                        self._save_data(
                            name_full + "/" + key, data[key], description[key], unit
                        )
                else:
                    if isinstance(unit, dict):
                        self._save_data(name_full + "/" + key, data[key], "", unit[key])
                    else:
                        self._save_data(name_full + "/" + key, data[key], "", unit)
        else:
            try:
                if data is None or len(data) == 0:
                    return
            except TypeError:
                data = np.array([data])

            group_name = os.path.dirname(name_full)
            if group_name in self.save:
                group = self.save.get_node(group_name)
                if not isinstance(group, class_name_dict["Group"]):
                    self.logger.warning(
                        f"{group_name} already there and no a group, deleting"
                    )
                    self.save.remove_node(group)
            self.save.create_array(
                group_name,
                os.path.basename(name_full),
                data,
                description,
                createparents=True,
            )
            self.save.get_node(name_full).attrs.unit = unit

        if attrs is not None:
            for key in attrs:
                key = str(key)
                self.save.get_node(name_full)._v_attrs[key] = attrs[key]

    def _transform(self, name, transform_fn, group="/maps", **kwargs):
        src = self.save.get_node(group + "/" + name).read()
        return transform_fn(src, **kwargs)

    def _gen_rule_transform(
        self,
        rule_src_name,
        transform_fn,
        transform_name,
        subarray_name=None,
        group=None,
    ):

        rule_src = self.rules[rule_src_name]

        if subarray_name is None:
            src_name = rule_src_name
            group_src = rule_src.group
            unit = rule_src.unit
            description = rule_src.description
        else:
            src_name = subarray_name
            group_src = rule_src.group + "/" + rule_src_name
            unit = rule_src.unit[subarray_name]
            description = rule_src.description[subarray_name]

        def fn(arg=None, **kwargs):
            if arg is None:
                return self._transform(
                    src_name, transform_fn, group=group_src, **kwargs
                )
            else:
                return self._transform(
                    src_name + "_" + str(arg), transform_fn, group=group_src, **kwargs
                )

        if group is None:
            group = group_src

        name = transform_name + "_" + rule_src_name

        self.rules[name] = Rule(
            fn,
            group=group,
            unit=unit,
            description=description,
            dependencies=[rule_src_name],
        )

    def apply(
        self,
        fn,
        name_array_in,
        name_array_out,
        unit_out=U.none,
        description="",
        recursive=True,
    ):
        array_in = self.get_value(name_array_in)
        if recursive and isinstance(array_in, dict):
            for key in array_in:
                self.apply(
                    fn,
                    name_array_in + "/" + key,
                    name_array_out + "/" + key,
                    unit_out,
                    description,
                )
                self.set_attribute(name_array_out, "unit", unit_out)
        else:
            try:
                array_out = fn(array_in)
            except TypeError:
                array_out = array_in

            self.set_value(name_array_out, array_out, description, unit_out)


def simple_getter(name, dset):
    return dset[name]


def vect_getter(name, i, dset):
    return dset[name][:, i]


def oct_vect_getter(name, i, dset):
    return dset[name][:, :, i]


def norm_getter(name, dset):
    return np.sqrt(np.sum(dset[name] ** 2, axis=1))


def oct_norm_getter(name, dset):
    return np.sqrt(np.sum(dset[name] ** 2, axis=2))