# Code for reading and writing the config file
#
# Copyright (C) 2016-2024  Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import configparser
import glob
import io
import logging
import os
import re
import shutil
import time

error = configparser.Error


######################################################################
# Config section parsing helper
######################################################################


class sentinel:
    pass


class ConfigWrapper:
    error = configparser.Error

    def __init__(self, printer, fileconfig, access_tracking, section):
        self.printer = printer
        self.fileconfig = fileconfig
        self.access_tracking = access_tracking
        self.section = section

    def get_printer(self):
        return self.printer

    def get_name(self):
        return self.section

    def _get_wrapper(
        self,
        parser,
        option,
        default,
        minval=None,
        maxval=None,
        above=None,
        below=None,
        note_valid=True,
    ):
        if not self.fileconfig.has_option(self.section, option):
            if default is not sentinel:
                if note_valid and default is not None:
                    acc_id = (self.section.lower(), option.lower())
                    self.access_tracking[acc_id] = default
                return default
            raise error(
                "Option '%s' in section '%s' must be specified" % (option, self.section)
            )
        try:
            v = parser(self.section, option)
        except self.error as e:
            raise
        except:
            raise error(
                "Unable to parse option '%s' in section '%s'" % (option, self.section)
            )
        if note_valid:
            self.access_tracking[(self.section.lower(), option.lower())] = v
        if minval is not None and v < minval:
            raise error(
                "Option '%s' in section '%s' must have minimum of %s"
                % (option, self.section, minval)
            )
        if maxval is not None and v > maxval:
            raise error(
                "Option '%s' in section '%s' must have maximum of %s"
                % (option, self.section, maxval)
            )
        if above is not None and v <= above:
            raise error(
                "Option '%s' in section '%s' must be above %s"
                % (option, self.section, above)
            )
        if below is not None and v >= below:
            raise self.error(
                "Option '%s' in section '%s' must be below %s"
                % (option, self.section, below)
            )
        return v

    def get(self, option, default=sentinel, note_valid=True):
        return self._get_wrapper(
            self.fileconfig.get, option, default, note_valid=note_valid
        )

    def getint(
        self, option, default=sentinel, minval=None, maxval=None, note_valid=True
    ):
        return self._get_wrapper(
            self.fileconfig.getint,
            option,
            default,
            minval,
            maxval,
            note_valid=note_valid,
        )

    def getfloat(
        self,
        option,
        default=sentinel,
        minval=None,
        maxval=None,
        above=None,
        below=None,
        note_valid=True,
    ):
        return self._get_wrapper(
            self.fileconfig.getfloat,
            option,
            default,
            minval,
            maxval,
            above,
            below,
            note_valid=note_valid,
        )

    def getboolean(self, option, default=sentinel, note_valid=True):
        return self._get_wrapper(
            self.fileconfig.getboolean, option, default, note_valid=note_valid
        )

    def getchoice(self, option, choices, default=sentinel, note_valid=True):
        if type(choices) == type([]):
            choices = {i: i for i in choices}
        if choices and type(list(choices.keys())[0]) == int:
            c = self.getint(option, default, note_valid=note_valid)
        else:
            c = self.get(option, default, note_valid=note_valid)
        if c not in choices:
            raise error(
                "Choice '%s' for option '%s' in section '%s'"
                " is not a valid choice" % (c, option, self.section)
            )
        return choices[c]

    def getlists(
        self,
        option,
        default=sentinel,
        seps=(",",),
        count=None,
        parser=str,
        note_valid=True,
    ):
        def lparser(value, pos):
            if len(value.strip()) == 0:
                # Return an empty list instead of [''] for empty string
                parts = []
            else:
                parts = [p.strip() for p in value.split(seps[pos])]
            if pos:
                # Nested list
                return tuple([lparser(p, pos - 1) for p in parts if p])
            res = [parser(p) for p in parts]
            if count is not None and len(res) != count:
                raise error(
                    "Option '%s' in section '%s' must have %d elements"
                    % (option, self.section, count)
                )
            return tuple(res)

        def fcparser(section, option):
            return lparser(self.fileconfig.get(section, option), len(seps) - 1)

        return self._get_wrapper(fcparser, option, default, note_valid=note_valid)

    def getlist(self, option, default=sentinel, sep=",", count=None, note_valid=True):
        return self.getlists(
            option, default, seps=(sep,), count=count, parser=str, note_valid=note_valid
        )

    def getintlist(
        self, option, default=sentinel, sep=",", count=None, note_valid=True
    ):
        return self.getlists(
            option, default, seps=(sep,), count=count, parser=int, note_valid=note_valid
        )

    def getfloatlist(
        self, option, default=sentinel, sep=",", count=None, note_valid=True
    ):
        return self.getlists(
            option,
            default,
            seps=(sep,),
            count=count,
            parser=float,
            note_valid=note_valid,
        )

    def getsection(self, section):
        return ConfigWrapper(
            self.printer, self.fileconfig, self.access_tracking, section
        )

    def has_section(self, section):
        return self.fileconfig.has_section(section)

    def get_prefix_sections(self, prefix):
        return [
            self.getsection(s)
            for s in self.fileconfig.sections()
            if s.startswith(prefix)
        ]

    def get_prefix_options(self, prefix):
        return [
            o for o in self.fileconfig.options(self.section) if o.startswith(prefix)
        ]

    def deprecate(self, option, value=None):
        if not self.fileconfig.has_option(self.section, option):
            return
        if value is None:
            msg = "Option '%s' in section '%s' is deprecated." % (option, self.section)
        else:
            msg = "Value '%s' in option '%s' in section '%s' is deprecated." % (
                value,
                option,
                self.section,
            )
        pconfig = self.printer.lookup_object("configfile")
        pconfig.deprecate(self.section, option, value, msg)


######################################################################
# Config file parsing (with include file support)
######################################################################


class ConfigFileReader:
    def read_config_file(self, filename):
        try:
            f = open(filename, "r")
            data = f.read()
            f.close()
        except:
            msg = "Unable to open config file %s" % (filename,)
            logging.exception(msg)
            raise error(msg)
        return data.replace("\r\n", "\n")

    def build_config_string(self, fileconfig):
        sfile = io.StringIO()
        fileconfig.write(sfile)
        return sfile.getvalue().strip()

    def append_fileconfig(self, fileconfig, data, filename):
        if not data:
            return
        # Strip trailing comments
        lines = data.split("\n")
        for i, line in enumerate(lines):
            pos = line.find("#")
            if pos >= 0:
                lines[i] = line[:pos]
        sbuffer = io.StringIO("\n".join(lines))
        fileconfig.read_file(sbuffer, filename)

    def _create_fileconfig(self):
        return configparser.RawConfigParser(
            strict=False, inline_comment_prefixes=(";", "#")
        )

    def build_fileconfig(self, data, filename):
        fileconfig = self._create_fileconfig()
        self.append_fileconfig(fileconfig, data, filename)
        return fileconfig

    def _resolve_include(self, source_filename, include_spec, fileconfig, visited):
        dirname = os.path.dirname(source_filename)
        include_spec = include_spec.strip()
        include_glob = os.path.join(dirname, include_spec)
        include_filenames = glob.glob(include_glob)
        if not include_filenames and not glob.has_magic(include_glob):
            # Empty set is OK if wildcard but not for direct file reference
            raise error("Include file '%s' does not exist" % (include_glob,))
        include_filenames.sort()
        for include_filename in include_filenames:
            include_data = self.read_config_file(include_filename)
            self._parse_config(include_data, include_filename, fileconfig, visited)
        return include_filenames

    def _parse_config(self, data, filename, fileconfig, visited):
        path = os.path.abspath(filename)
        if path in visited:
            raise error("Recursive include of config file '%s'" % (filename))
        visited.add(path)
        lines = data.split("\n")
        # Buffer lines between includes and parse as a unit so that overrides
        # in includes apply linearly as they do within a single file
        buf = []
        for line in lines:
            # Strip trailing comment
            pos = line.find("#")
            if pos >= 0:
                line = line[:pos]
            # Process include or buffer line
            mo = configparser.RawConfigParser.SECTCRE.match(line)
            header = mo and mo.group("header")
            if header and header.startswith("include "):
                self.append_fileconfig(fileconfig, "\n".join(buf), filename)
                del buf[:]
                include_spec = header[8:].strip()
                self._resolve_include(filename, include_spec, fileconfig, visited)
            else:
                buf.append(line)
        self.append_fileconfig(fileconfig, "\n".join(buf), filename)
        visited.remove(path)

    def build_fileconfig_with_includes(self, data, filename):
        fileconfig = self._create_fileconfig()
        self._parse_config(data, filename, fileconfig, set())
        return fileconfig


######################################################################
# Config auto save helper
######################################################################


class ConfigAutoSave:
    def __init__(self, printer):
        self.printer = printer
        self.fileconfig = None
        self.status_save_pending = {}
        self.save_config_pending = False
        gcode = self.printer.lookup_object("gcode")
        gcode.register_command(
            "SAVE_CONFIG", self.cmd_SAVE_CONFIG, desc=self.cmd_SAVE_CONFIG_help
        )

    comment_r = re.compile("[#;].*$")
    value_r = re.compile("[^A-Za-z0-9_].*$")

    def _strip_duplicates(self, data, fileconfig):
        # Comment out fields in 'data' that are defined in 'config'
        lines = data.split("\n")
        section = None
        is_dup_field = False
        for lineno, line in enumerate(lines):
            pruned_line = self.comment_r.sub("", line).rstrip()
            if not pruned_line:
                continue
            if pruned_line[0].isspace():
                if is_dup_field:
                    lines[lineno] = "#" + lines[lineno]
                continue
            is_dup_field = False
            if pruned_line[0] == "[":
                section = pruned_line[1:-1].strip()
                continue
            field = self.value_r.sub("", pruned_line)
            if fileconfig.has_option(section, field):
                is_dup_field = True
                lines[lineno] = "#" + lines[lineno]
        return "\n".join(lines)

    def load_main_config(self):
        regular_filename = self.printer.get_start_args()["config_file"]
        autosave_filename = self.printer.get_start_args()["saved_config"]
        cfgrdr = ConfigFileReader()
        regular_data = cfgrdr.read_config_file(regular_filename)
        # TODO: TOCTOU - future refactor
        if os.path.exists(autosave_filename):
            autosave_data = cfgrdr.read_config_file(autosave_filename)
        else:
            autosave_data = ""
        regular_fileconfig = cfgrdr.build_fileconfig_with_includes(
            regular_data, regular_filename
        )
        autosave_data = self._strip_duplicates(autosave_data, regular_fileconfig)
        self.fileconfig = cfgrdr.build_fileconfig(autosave_data, autosave_filename)
        cfgrdr.append_fileconfig(regular_fileconfig, autosave_data, autosave_filename)
        return regular_fileconfig, self.fileconfig

    def get_status(self, eventtime):
        return {
            "save_config_pending": self.save_config_pending,
            "save_config_pending_items": self.status_save_pending,
        }

    def set(self, section, option, value):
        if not self.fileconfig.has_section(section):
            self.fileconfig.add_section(section)
        svalue = str(value)
        self.fileconfig.set(section, option, svalue)
        pending = dict(self.status_save_pending)
        if not section in pending or pending[section] is None:
            pending[section] = {}
        else:
            pending[section] = dict(pending[section])
        pending[section][option] = svalue
        self.status_save_pending = pending
        self.save_config_pending = True
        logging.info("save_config: set [%s] %s = %s", section, option, svalue)

    def remove_section(self, section):
        if self.fileconfig.has_section(section):
            self.fileconfig.remove_section(section)
            pending = dict(self.status_save_pending)
            pending[section] = None
            self.status_save_pending = pending
            self.save_config_pending = True
        elif (
            section in self.status_save_pending
            and self.status_save_pending[section] is not None
        ):
            pending = dict(self.status_save_pending)
            del pending[section]
            self.status_save_pending = pending
            self.save_config_pending = True

    def _disallow_include_conflicts(self, regular_fileconfig):
        for section in self.fileconfig.sections():
            for option in self.fileconfig.options(section):
                if regular_fileconfig.has_option(section, option):
                    msg = (
                        "SAVE_CONFIG section '%s' option '%s' conflicts "
                        "with included value" % (section, option)
                    )
                    raise self.printer.command_error(msg)

    cmd_SAVE_CONFIG_help = "Overwrite config file and restart"

    def cmd_SAVE_CONFIG(self, gcmd):
        if not self.fileconfig.sections():
            return
        # Create string containing autosave data
        cfgrdr = ConfigFileReader()
        # TODO: This will no longer comment out duplicate sections in the main
        # config. Which is fine because they're ignored when the main config is
        # read. But maybe there should be a warning either here or at load as
        # there's no feedback mechanism anymore.
        autosave_data = cfgrdr.build_config_string(self.fileconfig) + "\n"
        autosave_filename = self.printer.get_start_args()["saved_config"]
        # Determine filenames
        datestr = time.strftime("-%Y%m%d_%H%M%S")
        backup_name = autosave_filename + datestr
        temp_name = autosave_filename + "_autosave"
        if autosave_filename.endswith(".cfg"):
            backup_name = autosave_filename[:-4] + datestr + ".cfg"
            temp_name = autosave_filename[:-4] + "_autosave.cfg"
        # Create new config file with temporary name and swap with main config
        logging.info(
            "SAVE_CONFIG to '%s' (backup in '%s')", autosave_filename, backup_name
        )
        try:
            f = open(temp_name, "w")
            f.write(autosave_data)
            f.close()
            try:
                shutil.copy2(autosave_filename, backup_name)
            except FileNotFoundError:
                pass
            os.rename(temp_name, autosave_filename)
        except:
            msg = "Unable to write config file during SAVE_CONFIG"
            logging.exception(msg)
            raise gcmd.error(msg)
        # Request a restart
        gcode = self.printer.lookup_object("gcode")
        gcode.request_restart("restart")


######################################################################
# Config validation (check for undefined options)
######################################################################


class ConfigValidate:
    def __init__(self, printer):
        self.printer = printer
        self.status_settings = {}
        self.access_tracking = {}
        self.autosave_options = {}

    def start_access_tracking(self, autosave_fileconfig):
        # Note autosave options for use during undefined options check
        self.autosave_options = {}
        for section in autosave_fileconfig.sections():
            for option in autosave_fileconfig.options(section):
                self.autosave_options[(section.lower(), option.lower())] = 1
        self.access_tracking = {}
        return self.access_tracking

    def check_unused(self, fileconfig):
        # Don't warn on fields set in autosave segment
        access_tracking = dict(self.access_tracking)
        access_tracking.update(self.autosave_options)
        # Note locally used sections
        valid_sections = {s: 1 for s, o in self.printer.lookup_objects()}
        valid_sections.update({s: 1 for s, o in access_tracking})
        # Validate that there are no undefined parameters in the config file
        for section_name in fileconfig.sections():
            section = section_name.lower()
            if section not in valid_sections:
                raise error("Section '%s' is not a valid config section" % (section,))
            for option in fileconfig.options(section_name):
                option = option.lower()
                if (section, option) not in access_tracking:
                    raise error(
                        "Option '%s' is not valid in section '%s'" % (option, section)
                    )
        # Setup get_status()
        self._build_status_settings()
        # Clear tracking state
        self.access_tracking.clear()
        self.autosave_options.clear()

    def _build_status_settings(self):
        self.status_settings = {}
        for (section, option), value in self.access_tracking.items():
            self.status_settings.setdefault(section, {})[option] = value

    def get_status(self, eventtime):
        return {"settings": self.status_settings}


######################################################################
# Main printer config tracking
######################################################################


class PrinterConfig:
    def __init__(self, printer):
        self.printer = printer
        self.autosave = ConfigAutoSave(printer)
        self.validate = ConfigValidate(printer)
        self.deprecated = {}
        self.runtime_warnings = []
        self.deprecate_warnings = []
        self.status_raw_config = {}
        self.status_warnings = []

    def get_printer(self):
        return self.printer

    def read_config(self, filename):
        cfgrdr = ConfigFileReader()
        data = cfgrdr.read_config_file(filename)
        fileconfig = cfgrdr.build_fileconfig(data, filename)
        return ConfigWrapper(self.printer, fileconfig, {}, "printer")

    def read_main_config(self):
        fileconfig, autosave_fileconfig = self.autosave.load_main_config()
        access_tracking = self.validate.start_access_tracking(autosave_fileconfig)
        config = ConfigWrapper(self.printer, fileconfig, access_tracking, "printer")
        self._build_status_config(config)
        return config

    def check_unused_options(self, config):
        self.validate.check_unused(config.fileconfig)

    # Deprecation warnings
    def runtime_warning(self, msg):
        logging.warning(msg)
        res = {"type": "runtime_warning", "message": msg}
        self.runtime_warnings.append(res)
        self.status_warnings = self.runtime_warnings + self.deprecate_warnings

    def deprecate(self, section, option, value=None, msg=None):
        key = (section, option, value)
        if key in self.deprecated and self.deprecated[key] == msg:
            return
        self.deprecated[key] = msg
        self.deprecate_warnings = []
        for (section, option, value), msg in self.deprecated.items():
            if value is None:
                res = {"type": "deprecated_option"}
            else:
                res = {"type": "deprecated_value", "value": value}
            res["message"] = msg
            res["section"] = section
            res["option"] = option
            self.deprecate_warnings.append(res)
        self.status_warnings = self.runtime_warnings + self.deprecate_warnings

    # Status reporting
    def _build_status_config(self, config):
        self.status_raw_config = {}
        for section in config.get_prefix_sections(""):
            self.status_raw_config[section.get_name()] = section_status = {}
            for option in section.get_prefix_options(""):
                section_status[option] = section.get(option, note_valid=False)

    def get_status(self, eventtime):
        status = {"config": self.status_raw_config, "warnings": self.status_warnings}
        status.update(self.autosave.get_status(eventtime))
        status.update(self.validate.get_status(eventtime))
        return status

    # Autosave functions
    def set(self, section, option, value):
        self.autosave.set(section, option, value)

    def remove_section(self, section):
        self.autosave.remove_section(section)