# coding=utf-8
import fnmatch
import json
import logging
import os
import re
import shutil
import subprocess
import sys
from abc import abstractmethod
from collections import namedtuple
from io import open

import typing

DEFAULT_TARGET = "esp32"

TARGET_PLACEHOLDER = "@t"
WILDCARD_PLACEHOLDER = "@w"
NAME_PLACEHOLDER = "@n"
FULL_NAME_PLACEHOLDER = "@f"
INDEX_PLACEHOLDER = "@i"

IDF_SIZE_PY = os.path.join(os.environ["IDF_PATH"], "tools", "idf_size.py")
SIZE_JSON_FN = 'size.json'

SDKCONFIG_LINE_REGEX = re.compile(r"^([^=]+)=\"?([^\"\n]*)\"?\n*$")

# If these keys are present in sdkconfig.defaults, they will be extracted and passed to CMake
SDKCONFIG_TEST_OPTS = [
    "EXCLUDE_COMPONENTS",
    "TEST_EXCLUDE_COMPONENTS",
    "TEST_COMPONENTS",
]

# These keys in sdkconfig.defaults are not propagated to the final sdkconfig file:
SDKCONFIG_IGNORE_OPTS = [
    "TEST_GROUPS"
]

# ConfigRule represents one --config argument of find_apps.py.
# file_name is the name of the sdkconfig file fragment, optionally with a single wildcard ('*' character).
# file_name can also be empty to indicate that the default configuration of the app should be used.
# config_name is the name of the corresponding build configuration, or None if the value of wildcard is to be used.
# For example:
#   filename='', config_name='default' — represents the default app configuration, and gives it a name 'default'
#   filename='sdkconfig.*', config_name=None - represents the set of configurations, names match the wildcard value
ConfigRule = namedtuple("ConfigRule", ["file_name", "config_name"])


def config_rules_from_str(rule_strings):  # type: (typing.List[str]) -> typing.List[ConfigRule]
    """
    Helper function to convert strings like 'file_name=config_name' into ConfigRule objects
    :param rule_strings: list of rules as strings
    :return: list of ConfigRules
    """
    rules = []  # type: typing.List[ConfigRule]
    for rule_str in rule_strings:
        items = rule_str.split("=", 2)
        rules.append(ConfigRule(items[0], items[1] if len(items) == 2 else None))
    return rules


def find_first_match(pattern, path):
    for root, _, files in os.walk(path):
        res = fnmatch.filter(files, pattern)
        if res:
            return os.path.join(root, res[0])
    return None


def rmdir(path, exclude_file_pattern=None):
    if not exclude_file_pattern:
        shutil.rmtree(path, ignore_errors=True)
        return

    for root, dirs, files in os.walk(path, topdown=False):
        for f in files:
            if not fnmatch.fnmatch(f, exclude_file_pattern):
                os.remove(os.path.join(root, f))
        for d in dirs:
            try:
                os.rmdir(os.path.join(root, d))
            except OSError:
                pass


class BuildItem(object):
    """
    Instance of this class represents one build of an application.
    The parameters which distinguish the build are passed to the constructor.
    """

    def __init__(
            self,
            app_path,
            work_dir,
            build_path,
            build_log_path,
            target,
            sdkconfig_path,
            config_name,
            build_system,
            preserve_artifacts,
    ):
        # These internal variables store the paths with environment variables and placeholders;
        # Public properties with similar names use the _expand method to get the actual paths.
        self._app_dir = app_path
        self._work_dir = work_dir
        self._build_dir = build_path
        self._build_log_path = build_log_path

        self.sdkconfig_path = sdkconfig_path
        self.config_name = config_name
        self.target = target
        self.build_system = build_system

        self.preserve = preserve_artifacts

        self._app_name = os.path.basename(os.path.normpath(app_path))
        self.size_json_fp = None

        # Some miscellaneous build properties which are set later, at the build stage
        self.index = None
        self.verbose = False
        self.dry_run = False
        self.keep_going = False

        self.work_path = self.work_dir or self.app_dir
        if not self.build_dir:
            self.build_path = os.path.join(self.work_path, "build")
        elif os.path.isabs(self.build_dir):
            self.build_path = self.build_dir
        else:
            self.build_path = os.path.normpath(os.path.join(self.work_path, self.build_dir))

    @property
    def app_dir(self):
        """
        :return: directory of the app
        """
        return self._expand(self._app_dir)

    @property
    def work_dir(self):
        """
        :return: directory where the app should be copied to, prior to the build. Can be None, which means that the app
                 directory should be used.
        """
        return self._expand(self._work_dir)

    @property
    def build_dir(self):
        """
        :return: build directory, either relative to the work directory (if relative path is used) or absolute path.
        """
        return self._expand(self._build_dir)

    @property
    def build_log_path(self):
        """
        :return: path of the build log file
        """
        return self._expand(self._build_log_path)

    def __repr__(self):
        return "({}) Build app {} for target {}, sdkconfig {} in {}".format(
            self.build_system,
            self.app_dir,
            self.target,
            self.sdkconfig_path or "(default)",
            self.build_dir,
        )

    def to_json(self):  # type: () -> str
        """
        :return: JSON string representing this object
        """
        return self._to_json(self._app_dir, self._work_dir, self._build_dir, self._build_log_path)

    def to_json_expanded(self):  # type: () -> str
        """
        :return: JSON string representing this object, with all placeholders in paths expanded
        """
        return self._to_json(self.app_dir, self.work_dir, self.build_dir, self.build_log_path)

    def _to_json(self, app_dir, work_dir, build_dir, build_log_path):  # type: (str, str, str, str) -> str
        """
        Internal function, called by to_json and to_json_expanded
        """
        return json.dumps({
            "build_system": self.build_system,
            "app_dir": app_dir,
            "work_dir": work_dir,
            "build_dir": build_dir,
            "build_log_path": build_log_path,
            "sdkconfig": self.sdkconfig_path,
            "config": self.config_name,
            "target": self.target,
            "verbose": self.verbose,
            "preserve": self.preserve,
        })

    @staticmethod
    def from_json(json_str):  # type: (typing.Text) -> BuildItem
        """
        :return: Get the BuildItem from a JSON string
        """
        d = json.loads(str(json_str))
        result = BuildItem(
            app_path=d["app_dir"],
            work_dir=d["work_dir"],
            build_path=d["build_dir"],
            build_log_path=d["build_log_path"],
            sdkconfig_path=d["sdkconfig"],
            config_name=d["config"],
            target=d["target"],
            build_system=d["build_system"],
            preserve_artifacts=d["preserve"]
        )
        result.verbose = d["verbose"]
        return result

    def _expand(self, path):  # type: (str) -> str
        """
        Internal method, expands any of the placeholders in {app,work,build} paths.
        """
        if not path:
            return path

        if self.index is not None:
            path = path.replace(INDEX_PLACEHOLDER, str(self.index))
        path = path.replace(TARGET_PLACEHOLDER, self.target)
        path = path.replace(NAME_PLACEHOLDER, self._app_name)
        if (FULL_NAME_PLACEHOLDER in path):  # to avoid recursion to the call to app_dir in the next line:
            path = path.replace(FULL_NAME_PLACEHOLDER, self.app_dir.replace(os.path.sep, "_"))
        wildcard_pos = path.find(WILDCARD_PLACEHOLDER)
        if wildcard_pos != -1:
            if self.config_name:
                # if config name is defined, put it in place of the placeholder
                path = path.replace(WILDCARD_PLACEHOLDER, self.config_name)
            else:
                # otherwise, remove the placeholder and one character on the left
                # (which is usually an underscore, dash, or other delimiter)
                left_of_wildcard = max(0, wildcard_pos - 1)
                right_of_wildcard = wildcard_pos + len(WILDCARD_PLACEHOLDER)
                path = path[0:left_of_wildcard] + path[right_of_wildcard:]
        path = os.path.expandvars(path)
        return path

    def get_size_json_fp(self):
        if self.size_json_fp and os.path.exists(self.size_json_fp):
            return self.size_json_fp

        assert os.path.exists(self.build_path)
        assert os.path.exists(self.work_path)

        map_file = find_first_match('*.map', self.build_path)
        if not map_file:
            raise ValueError('.map file not found under "{}"'.format(self.build_path))

        size_json_fp = os.path.join(self.build_path, SIZE_JSON_FN)
        idf_size_args = [
            sys.executable,
            IDF_SIZE_PY,
            '--json',
            '-o', size_json_fp,
            map_file
        ]
        subprocess.check_call(idf_size_args)
        return size_json_fp

    def write_size_info(self, size_info_fs):
        if not self.size_json_fp or (not os.path.exists(self.size_json_fp)):
            raise OSError('Run get_size_json_fp() for app {} after built binary'.format(self.app_dir))
        size_info_dict = {
            'app_name': self._app_name,
            'config_name': self.config_name,
            'target': self.target,
            'path': self.size_json_fp,
        }
        size_info_fs.write(json.dumps(size_info_dict) + '\n')


class BuildSystem(object):
    """
    Class representing a build system.
    Derived classes implement the methods below.
    Objects of these classes aren't instantiated, instead the class (type object) is used.
    """
    NAME = "undefined"
    SUPPORTED_TARGETS_REGEX = re.compile(r'Supported [Tt]argets((?:[\s|]+(?:ESP[0-9A-Z\-]+))+)')

    @classmethod
    def build_prepare(cls, build_item):
        app_path = build_item.app_dir
        work_path = build_item.work_path
        build_path = build_item.build_path

        if work_path != app_path:
            if os.path.exists(work_path):
                logging.debug("Work directory {} exists, removing".format(work_path))
                if not build_item.dry_run:
                    shutil.rmtree(work_path)
            logging.debug("Copying app from {} to {}".format(app_path, work_path))
            if not build_item.dry_run:
                shutil.copytree(app_path, work_path)

        if os.path.exists(build_path):
            logging.debug("Build directory {} exists, removing".format(build_path))
            if not build_item.dry_run:
                shutil.rmtree(build_path)

        if not build_item.dry_run:
            os.makedirs(build_path)

        # Prepare the sdkconfig file, from the contents of sdkconfig.defaults (if exists) and the contents of
        # build_info.sdkconfig_path, i.e. the config-specific sdkconfig file.
        #
        # Note: the build system supports taking multiple sdkconfig.defaults files via SDKCONFIG_DEFAULTS
        # CMake variable. However here we do this manually to perform environment variable expansion in the
        # sdkconfig files.
        sdkconfig_defaults_list = ["sdkconfig.defaults", "sdkconfig.defaults." + build_item.target]
        if build_item.sdkconfig_path:
            sdkconfig_defaults_list.append(build_item.sdkconfig_path)

        sdkconfig_file = os.path.join(work_path, "sdkconfig")
        if os.path.exists(sdkconfig_file):
            logging.debug("Removing sdkconfig file: {}".format(sdkconfig_file))
            if not build_item.dry_run:
                os.unlink(sdkconfig_file)

        logging.debug("Creating sdkconfig file: {}".format(sdkconfig_file))
        extra_cmakecache_items = {}
        if not build_item.dry_run:
            with open(sdkconfig_file, "w") as f_out:
                for sdkconfig_name in sdkconfig_defaults_list:
                    sdkconfig_path = os.path.join(work_path, sdkconfig_name)
                    if not sdkconfig_path or not os.path.exists(sdkconfig_path):
                        continue
                    logging.debug("Appending {} to sdkconfig".format(sdkconfig_name))
                    with open(sdkconfig_path, "r") as f_in:
                        for line in f_in:
                            if not line.endswith("\n"):
                                line += "\n"
                            if cls.NAME == 'cmake':
                                m = SDKCONFIG_LINE_REGEX.match(line)
                                key = m.group(1) if m else None
                                if key in SDKCONFIG_TEST_OPTS:
                                    extra_cmakecache_items[key] = m.group(2)
                                    continue
                                if key in SDKCONFIG_IGNORE_OPTS:
                                    continue
                            f_out.write(os.path.expandvars(line))
        else:
            for sdkconfig_name in sdkconfig_defaults_list:
                sdkconfig_path = os.path.join(app_path, sdkconfig_name)
                if not sdkconfig_path:
                    continue
                logging.debug("Considering sdkconfig {}".format(sdkconfig_path))
                if not os.path.exists(sdkconfig_path):
                    continue
                logging.debug("Appending {} to sdkconfig".format(sdkconfig_name))

        # The preparation of build is finished. Implement the build part in sub classes.
        if cls.NAME == 'cmake':
            return build_path, work_path, extra_cmakecache_items
        else:
            return build_path, work_path

    @staticmethod
    @abstractmethod
    def build(build_item):
        pass

    @staticmethod
    @abstractmethod
    def is_app(path):
        pass

    @staticmethod
    def _read_readme(app_path):
        # Markdown supported targets should be:
        # e.g. | Supported Targets | ESP32 |
        #      | ----------------- | ----- |
        # reStructuredText supported targets should be:
        # e.g. ================= =====
        #      Supported Targets ESP32
        #      ================= =====
        def get_md_or_rst(app_path):
            readme_path = os.path.join(app_path, 'README.md')
            if not os.path.exists(readme_path):
                readme_path = os.path.join(app_path, 'README.rst')
                if not os.path.exists(readme_path):
                    return None
            return readme_path

        readme_path = get_md_or_rst(app_path)
        # Handle sub apps situation, e.g. master-slave
        if not readme_path:
            readme_path = get_md_or_rst(os.path.dirname(app_path))
        if not readme_path:
            return None
        with open(readme_path, "r", encoding='utf8') as readme_file:
            return readme_file.read()

    @staticmethod
    @abstractmethod
    def supported_targets(app_path):
        pass


class BuildError(RuntimeError):
    pass


def setup_logging(args):
    """
    Configure logging module according to the number of '--verbose'/'-v' arguments and the --log-file argument.
    :param args: namespace obtained from argparse
    """
    if not args.verbose:
        log_level = logging.WARNING
    elif args.verbose == 1:
        log_level = logging.INFO
    else:
        log_level = logging.DEBUG

    logging.basicConfig(
        format="%(levelname)s: %(message)s",
        stream=args.log_file or sys.stderr,
        level=log_level,
    )