#!/usr/bin/python3 -OO
# Copyright 2007-2026 by The SABnzbd-Team (sabnzbd.org)
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

"""
sabnzbd.bpsmeter - bpsmeter
"""

import time
import logging
import re
from collections import deque
from itertools import islice, repeat
from typing import Optional

import sabnzbd
from sabnzbd.constants import BYTES_FILE_NAME, KIBI
from sabnzbd.misc import to_units
import sabnzbd.cfg as cfg

DAY = float(24 * 60 * 60)
WEEK = DAY * 7
DAYS = (0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31)
BPS_LIST_MAX = 275

RE_DAY = re.compile(r"^\s*(\d+)[^:]*")
RE_HHMM = re.compile(r"(\d+):(\d+)\s*$")


def tomorrow(t: float) -> float:
    """Return timestamp for tomorrow (midnight)"""
    now = time.localtime(t)
    ntime = (now[0], now[1], now[2], 0, 0, 0, now[6], now[7], now[8])
    return time.mktime(ntime) + DAY


def this_week(t: float) -> float:
    """Return timestamp for start of this week (monday)"""
    while 1:
        tm = time.localtime(t)
        if tm.tm_wday == 0:
            break
        t -= DAY
    monday = (tm.tm_year, tm.tm_mon, tm.tm_mday, 0, 0, 0, 0, 0, tm.tm_isdst)
    return time.mktime(monday)


def next_week(t: float) -> float:
    """Return timestamp for start of next week (monday)"""
    return this_week(t) + WEEK


def this_month(t: float) -> float:
    """Return timestamp for start of next month"""
    now = time.localtime(t)
    ntime = (now[0], now[1], 1, 0, 0, 0, 0, 0, now[8])
    return time.mktime(ntime)


def last_month_day(tm: time.struct_time) -> int:
    """Return last day of this month"""
    year, month = tm[:2]
    day = DAYS[month]
    # This simple formula for leap years is good enough
    if day == 28 and (year % 4) == 0:
        day = 29
    return day


def next_month(t: float) -> float:
    """Return timestamp for start of next month"""
    now = time.localtime(t)
    month = now.tm_mon + 1
    year = now.tm_year
    if month > 12:
        month = 1
        year += 1
    ntime = (year, month, 1, 0, 0, 0, 0, 0, now[8])
    return time.mktime(ntime)


class BPSMeter:
    __slots__ = (
        "start_time",
        "log_time",
        "speed_log_time",
        "last_update",
        "bps",
        "bps_list",
        "server_bps",
        "cached_amount",
        "sum_cached_amount",
        "day_total",
        "week_total",
        "month_total",
        "grand_total",
        "timeline_total",
        "article_stats_tried",
        "article_stats_failed",
        "delayed_assembler",
        "day_label",
        "end_of_day",
        "end_of_week",
        "end_of_month",
        "q_day",
        "q_period",
        "quota",
        "left",
        "have_quota",
        "q_time",
        "q_hour",
        "q_minute",
        "quota_enabled",
        "quota_notifications_sent",
    )

    def __init__(self):
        t = time.time()
        self.start_time = t
        self.log_time = t
        self.speed_log_time = t
        self.last_update = t
        self.bps = 0.0
        self.bps_list: deque[int] = deque(repeat(0, BPS_LIST_MAX), maxlen=BPS_LIST_MAX)

        self.server_bps: dict[str, float] = {}
        self.cached_amount: dict[str, int] = {}
        self.sum_cached_amount: int = 0
        self.day_total: dict[str, int] = {}
        self.week_total: dict[str, int] = {}
        self.month_total: dict[str, int] = {}
        self.grand_total: dict[str, int] = {}

        self.timeline_total: dict[str, dict[str, int]] = {}

        self.article_stats_tried: dict[str, dict[str, int]] = {}
        self.article_stats_failed: dict[str, dict[str, int]] = {}

        self.delayed_assembler: int = 0

        self.day_label: str = time.strftime("%Y-%m-%d")
        self.end_of_day: float = tomorrow(t)  # Time that current day will end
        self.end_of_week: float = next_week(t)  # Time that current day will end
        self.end_of_month: float = next_month(t)  # Time that current month will end
        self.q_day = 1  # Day of quota reset
        self.q_period = "m"  # Daily/Weekly/Monthly quota = d/w/m
        self.quota = 0.0  # Quota
        self.left = 0.0  # Remaining quota
        self.have_quota = False  # Flag for quota active
        self.q_time = 0  # Next reset time for quota
        self.q_hour = 0  # Quota reset hour
        self.q_minute = 0  # Quota reset minute
        self.quota_enabled: bool = True  # Scheduled quota enable/disable
        self.quota_notifications_sent: int = 0  # Track highest quota threshold that has been notified

    def save(self):
        """Save admin to disk"""
        sabnzbd.filesystem.save_admin(
            (
                self.last_update,
                self.grand_total,
                self.day_total,
                self.week_total,
                self.month_total,
                self.end_of_day,
                self.end_of_week,
                self.end_of_month,
                self.quota,
                self.left,
                self.q_time,
                self.timeline_total,
                self.article_stats_tried,
                self.article_stats_failed,
            ),
            BYTES_FILE_NAME,
        )

    def defaults(self):
        """Get the latest data from the database and assign to a fake server"""
        logging.debug("Setting default BPS meter values")
        with sabnzbd.database.HistoryDB() as history_db:
            grand, month, week = history_db.get_history_size()
        self.grand_total = {}
        self.month_total = {}
        self.week_total = {}
        self.day_total = {}
        if grand:
            self.grand_total["x"] = grand
        if month:
            self.month_total["x"] = month
        if week:
            self.week_total["x"] = week
        self.quota = self.left = cfg.quota_size.get_float()

    def read(self):
        """Read admin from disk, return True when pause is needed"""
        res = False
        quota = self.left = cfg.quota_size.get_float()  # Quota for this period
        self.have_quota = bool(cfg.quota_size())
        data = sabnzbd.filesystem.load_admin(BYTES_FILE_NAME)
        try:
            (
                self.last_update,
                self.grand_total,
                self.day_total,
                self.week_total,
                self.month_total,
                self.end_of_day,
                self.end_of_week,
                self.end_of_month,
                self.quota,
                self.left,
                self.q_time,
                self.timeline_total,
            ) = data[:12]

            # Article statistics were only added in 3.2.x
            if len(data) > 12:
                self.article_stats_tried, self.article_stats_failed = data[12:14]

            # Clean the data, it could have invalid values in older versions
            for server in self.timeline_total:
                for data_data in self.timeline_total[server]:
                    if not isinstance(self.timeline_total[server][data_data], int):
                        self.timeline_total[server][data_data] = 0

            # Trigger quota actions
            if abs(quota - self.quota) > 0.5:
                self.change_quota()
            res = self.reset_quota()
        except Exception:
            self.defaults()
        return res

    def init_server_stats(self, server: Optional[str] = None):
        """Initialize counters for "server" """
        if server not in self.cached_amount:
            self.cached_amount[server] = 0
            self.server_bps[server] = 0.0
        if server not in self.day_total:
            self.day_total[server] = 0
        if server not in self.week_total:
            self.week_total[server] = 0
        if server not in self.month_total:
            self.month_total[server] = 0
        if server not in self.grand_total:
            self.grand_total[server] = 0
        if server not in self.timeline_total:
            self.timeline_total[server] = {}
        if self.day_label not in self.timeline_total[server]:
            self.timeline_total[server][self.day_label] = 0
        if server not in self.server_bps:
            self.server_bps[server] = 0.0
        if server not in self.article_stats_tried:
            self.article_stats_tried[server] = {}
            self.article_stats_failed[server] = {}
        if self.day_label not in self.article_stats_tried[server]:
            self.article_stats_tried[server][self.day_label] = 0
            self.article_stats_failed[server][self.day_label] = 0

    def update(self, server: Optional[str] = None, amount: int = 0):
        """Update counters for "server" with "amount" bytes"""
        # Add amount to temporary storage
        if server:
            self.cached_amount[server] += amount
            self.sum_cached_amount += amount
            return

        t = time.time()

        if t > self.end_of_day:
            # Current day passed, get new end of day
            self.day_label = time.strftime("%Y-%m-%d")
            self.end_of_day = tomorrow(t) - 1.0
            self.day_total = {}

            # Reset delayed counters so they don't go too high
            self.delayed_assembler = 0

            # Check end of week and end of month
            if t > self.end_of_week:
                self.week_total = {}
                self.end_of_week = next_week(t) - 1.0
            if t > self.end_of_month:
                self.month_total = {}
                self.end_of_month = next_month(t) - 1.0

            # Need to reset all counters
            for server in sabnzbd.Downloader.servers[:]:
                self.init_server_stats(server.id)

        # Cache dict references for faster access
        day_total = self.day_total
        week_total = self.week_total
        month_total = self.month_total
        grand_total = self.grand_total
        timeline_total = self.timeline_total
        cached_amount = self.cached_amount
        server_bps = self.server_bps

        start_time = self.start_time
        last_update = self.last_update
        # Minimum epsilon to avoid division by zero
        dt_total = max(t - start_time, 1e-6)
        dt_last = max(last_update - start_time, 1e-6)

        # Add amounts that have been stored temporarily to statistics
        for srv in self.cached_amount:
            if cached := self.cached_amount[srv]:
                day_total[srv] += cached
                week_total[srv] += cached
                month_total[srv] += cached
                grand_total[srv] += cached
                timeline_total[srv][self.day_label] += cached

                # Reset for next time
                cached_amount[srv] = 0

            # Update server bps
            server_bps[srv] = (server_bps[srv] * dt_last + cached) / dt_total

        # Quota check
        total_cached = self.sum_cached_amount
        if self.have_quota and self.quota_enabled:
            self.left -= total_cached
            self.check_quota()

        # Speedometer
        self.bps = (self.bps * dt_last + total_cached) / dt_total

        self.sum_cached_amount = 0
        self.last_update = t

        check_time = t - 5.0

        if start_time < check_time:
            self.start_time = check_time

        if self.bps < 0.01:
            self.reset()

        elif self.log_time < check_time:
            logging.debug("Speed: %sB/s", to_units(self.bps))
            self.log_time = t

        if self.speed_log_time < (t - 1.0):
            self.add_empty_time()
            self.bps_list.append(int(self.bps / KIBI))
            self.speed_log_time = t

    def register_server_article_tried(self, server: str):
        """Keep track how many articles were tried for each server"""
        self.article_stats_tried[server][self.day_label] += 1

    def register_server_article_failed(self, server: str):
        """Keep track how many articles failed for each server"""
        self.article_stats_failed[server][self.day_label] += 1

    def reset(self):
        t = time.time()
        self.start_time = t
        self.log_time = t
        self.last_update = t

        # Reset general BPS and the for all servers
        self.bps = 0.0
        for server in self.server_bps:
            self.server_bps[server] = 0.0

    def add_empty_time(self):
        # Extra zeros, but never more than the maximum!
        t = time.time()
        nr_diffs = min(int(t - self.speed_log_time), BPS_LIST_MAX)
        if nr_diffs > 1:
            # The deque trims itself to the max-length, dropping the oldest entries
            self.bps_list.extend(repeat(0, nr_diffs))
            self.speed_log_time = t

    def get_sums(self):
        """return tuple of grand, month, week, day totals"""
        return (
            sum(self.grand_total.values()),
            sum(self.month_total.values()),
            sum(self.week_total.values()),
            sum(self.day_total.values()),
        )

    def amounts(self, server: str):
        """Return grand, month, week, day and article totals for specified server"""
        return (
            self.grand_total.get(server, 0),
            self.month_total.get(server, 0),
            self.week_total.get(server, 0),
            self.day_total.get(server, 0),
            self.timeline_total.get(server, {}),
            self.article_stats_tried.get(server, {}),
            self.article_stats_failed.get(server, {}),
        )

    def clear_server(self, server: str):
        """Clean counters for specified server"""
        if server in self.day_total:
            del self.day_total[server]
        if server in self.week_total:
            del self.week_total[server]
        if server in self.month_total:
            del self.month_total[server]
        if server in self.grand_total:
            del self.grand_total[server]
        if server in self.timeline_total:
            del self.timeline_total[server]
        if server in self.article_stats_tried:
            del self.article_stats_tried[server]
        if server in self.article_stats_failed:
            del self.article_stats_failed[server]
        self.init_server_stats(server)
        self.save()

    def get_bps_list(self):
        refresh_rate = int(cfg.refresh_rate()) if cfg.refresh_rate() else 1
        self.add_empty_time()
        # We record every second, but display at the user's refresh-rate
        return list(islice(self.bps_list, 0, None, refresh_rate))

    def check_quota(self):
        """Pause the queue when all quota is spent
        Notify at specific quota usages (75%, 90%, 100%)
        """
        if self.left <= 0.0:
            if not sabnzbd.Downloader.paused:
                sabnzbd.Downloader.pause()
                logging.warning(T("Quota spent, pausing downloading"))

        # Guard against zero division
        if self.quota:
            # Check for quota notifications (75%, 90%, 100%)
            # Only send notification for the highest applicable threshold that hasn't been notified yet
            used_percentage = ((self.quota - self.left) / self.quota) * 100
            if used_percentage >= 100 and self.quota_notifications_sent < 100:
                sabnzbd.notifier.send_notification(T("Quota"), T("Quota spent, pausing downloading"), "quota")
            elif used_percentage >= 90 and self.quota_notifications_sent < 90:
                sabnzbd.notifier.send_notification(
                    T("Quota"),
                    T("Quota limit warning (%d%%)") % used_percentage,
                    "quota",
                )
            elif used_percentage >= 75 and self.quota_notifications_sent < 75:
                sabnzbd.notifier.send_notification(
                    T("Quota"),
                    T("Quota limit warning (%d%%)") % used_percentage,
                    "quota",
                )
            self.quota_notifications_sent = used_percentage

    def reset_quota(self, force: bool = False):
        """Check if it's time to reset the quota, optionally resuming
        Return True, when still paused or should be paused
        """
        if force or (self.have_quota and time.time() > (self.q_time - 50)):
            self.quota = self.left = cfg.quota_size.get_float()
            self.quota_notifications_sent = 0
            logging.info("Quota was reset to %s", self.quota)
            if cfg.quota_resume():
                logging.info("Auto-resume due to quota reset")
                sabnzbd.notifier.send_notification(T("Quota"), T("Downloading resumed after quota reset"), "quota")
                sabnzbd.Downloader.resume()
            self.next_reset()
            return False
        else:
            return True

    def next_reset(self, t: Optional[float] = None):
        """Determine next reset time"""
        t = t or time.time()
        tm = time.localtime(t)
        if self.q_period == "d":
            nx = (tm[0], tm[1], tm[2], self.q_hour, self.q_minute, 0, 0, 0, tm[8])
            if (tm.tm_hour * 60 + tm.tm_min) >= (self.q_hour * 60 + self.q_minute):
                # If today's moment has passed, it will happen tomorrow
                t = time.mktime(nx) + 24 * 3600
                tm = time.localtime(t)
        elif self.q_period == "w":
            if self.q_day < tm.tm_wday + 1 or (
                self.q_day == tm.tm_wday + 1 and (tm.tm_hour * 60 + tm.tm_min) >= (self.q_hour * 60 + self.q_minute)
            ):
                tm = time.localtime(next_week(t))
            dif = abs(self.q_day - tm.tm_wday - 1)
            t = time.mktime(tm) + dif * 24 * 3600
            tm = time.localtime(t)
        elif self.q_period == "m":
            if self.q_day < tm.tm_mday or (
                self.q_day == tm.tm_mday and (tm.tm_hour * 60 + tm.tm_min) >= (self.q_hour * 60 + self.q_minute)
            ):
                tm = time.localtime(next_month(t))
            day = min(last_month_day(tm), self.q_day)
            tm = (tm[0], tm[1], day, self.q_hour, self.q_minute, 0, 0, 0, tm[8])
        else:
            return
        tm = (tm[0], tm[1], tm[2], self.q_hour, self.q_minute, 0, 0, 0, tm[8])
        self.q_time = time.mktime(tm)
        logging.debug("Will reset quota at %s", tm)

    def change_quota(self, allow_resume: bool = True):
        """Update quota, potentially pausing downloader"""
        if not self.have_quota and self.quota < 0.5:
            # Never set, use last period's size
            per = cfg.quota_period()
            sums = self.get_sums()
            if per == "d":
                self.left = sums[3]
            elif per == "w":
                self.left = sums[2]
            elif per == "m":
                self.left = sums[1]

        self.have_quota = bool(cfg.quota_size())
        if self.have_quota:
            quota = cfg.quota_size.get_float()
            if self.quota:
                # Quota change, recalculate amount left
                self.left = quota - (self.quota - self.left)
            else:
                # If previously no quota, self.left holds this period's usage
                self.left = quota - self.left
            self.quota = quota
        else:
            self.quota = self.left = 0
        self.update()
        self.next_reset()
        if self.left > 0.5 and allow_resume:
            self.resume()

    def get_quota(self):
        """If quota active, return check-function, hour, minute"""
        if self.have_quota:
            self.q_period = cfg.quota_period()[0].lower()
            self.q_day = 1
            self.q_hour = self.q_minute = 0
            # Pattern = <day#> <hh:mm>
            # The <day> and <hh:mm> part can both be optional
            txt = cfg.quota_day().lower()
            if m := RE_DAY.search(txt):
                self.q_day = int(m.group(1))
            if m := RE_HHMM.search(txt):
                self.q_hour = int(m.group(1))
                self.q_minute = int(m.group(2))
            if self.q_period == "w":
                self.q_day = max(1, self.q_day)
                self.q_day = min(7, self.q_day)
            elif self.q_period == "m":
                self.q_day = max(1, self.q_day)
                self.q_day = min(31, self.q_day)
            else:
                self.q_day = 1
            self.change_quota(allow_resume=False)
            return quota_handler, self.q_hour, self.q_minute
        else:
            return None, 0, 0

    def set_status(self, status: bool, action: bool = True):
        """Disable/enable quota management"""
        self.quota_enabled = status
        if action and not status:
            self.resume()

    @staticmethod
    def resume():
        """Resume downloading"""
        if cfg.quota_resume() and sabnzbd.Downloader.paused:
            sabnzbd.Downloader.resume()


def quota_handler():
    """To be called from scheduler"""
    logging.debug("Checking quota")
    sabnzbd.BPSMeter.reset_quota()
