"""Timing and TPS management for simulation."""

import time
from dataclasses import dataclass
from typing import Optional
from .event_bus import EventBus, EventType, Event


@dataclass
class TimingState:
    """Current timing state."""
    tps: float
    is_paused: bool = False
    sprint_mode: bool = False
    speed_multiplier: float = 1.0

    def __post_init__(self):
        if self.speed_multiplier == 0:
            self.speed_multiplier = 1.0


class TimingController:
    """Manages simulation timing, TPS, and pause states."""

    def __init__(self, default_tps: float = 40.0, event_bus: Optional[EventBus] = None):
        self.default_tps = default_tps
        self.state = TimingState(tps=default_tps)
        self.event_bus = event_bus

        # Timing variables
        self.last_tick_time = time.perf_counter()
        self.last_tps_time = time.perf_counter()
        self.tick_counter = 0
        self.total_ticks = 0
        self.actual_tps = 0

        # Sprint mode specific
        self.sprint_start_time = None

    def set_tps(self, tps: float):
        """Set target TPS."""
        if tps > 0:
            self.state.tps = max(1.0, min(1000.0, tps))
            self.state.speed_multiplier = self.state.tps / self.default_tps
            self._notify_state_change()

    def set_speed_multiplier(self, multiplier: float):
        """Set speed multiplier for simulation."""
        if multiplier > 0:
            self.state.speed_multiplier = max(0.1, min(10.0, multiplier))
            self.state.tps = self.default_tps * self.state.speed_multiplier
            self._notify_state_change()

    def toggle_pause(self):
        """Toggle pause state."""
        self.state.is_paused = not self.state.is_paused
        if self.state.is_paused:
            # Reset timing when paused
            self.last_tick_time = time.perf_counter()
            self.last_tps_time = time.perf_counter()
        self._notify_state_change()

    def set_pause(self, paused: bool):
        """Set pause state directly."""
        if self.state.is_paused != paused:
            self.toggle_pause()

    def toggle_sprint_mode(self):
        """Toggle sprint mode."""
        self.state.sprint_mode = not self.state.sprint_mode
        if self.state.sprint_mode:
            self.sprint_start_time = time.perf_counter()
        else:
            self.sprint_start_time = None
        self._notify_state_change()

    def set_sprint_mode(self, enabled: bool):
        """Set sprint mode directly."""
        if self.state.sprint_mode != enabled:
            self.toggle_sprint_mode()

    def should_tick(self) -> bool:
        """Check if simulation should tick based on timing."""
        if self.state.is_paused:
            return False

        if self.state.sprint_mode:
            return True

        tick_interval = 1.0 / self.state.tps
        current_time = time.perf_counter()
        return current_time - self.last_tick_time >= tick_interval

    def update_timing(self):
        """Update timing variables after a tick."""
        current_time = time.perf_counter()

        # Update tick counters first
        self.tick_counter += 1
        self.total_ticks += 1

        if self.state.sprint_mode and self.sprint_start_time:
            # In sprint mode, calculate TPS based on total sprint duration
            sprint_duration = current_time - self.sprint_start_time
            if sprint_duration > 0:
                self.actual_tps = self.tick_counter / sprint_duration
            else:
                self.actual_tps = 0
        else:
            # Normal mode TPS calculation using sliding window for more responsive display
            elapsed_time = current_time - self.last_tps_time

            # Update TPS more frequently for responsive display
            if elapsed_time >= 0.5:  # Update every 500ms instead of 1 second
                # Calculate actual TPS based on elapsed time
                self.actual_tps = self.tick_counter / elapsed_time

                # Reset for next measurement period
                self.last_tps_time = current_time
                self.tick_counter = 0

        # Update last tick time for next tick calculation - advance by tick interval
        if not self.state.sprint_mode:
            tick_interval = 1.0 / self.state.tps
            self.last_tick_time += tick_interval

        self._notify_timing_update()

    def get_display_tps(self) -> int:
        """Get TPS rounded to nearest whole number for display."""
        return round(self.actual_tps)

    def reset_counters(self):
        """Reset timing counters."""
        self.tick_counter = 0
        self.total_ticks = 0
        self.actual_tps = 0
        self.last_tick_time = time.perf_counter()
        self.last_tps_time = time.perf_counter()
        if self.state.sprint_mode:
            self.sprint_start_time = time.perf_counter()

    def get_tick_interval(self) -> float:
        """Get current tick interval in seconds."""
        return 1.0 / self.state.tps if self.state.tps > 0 else 1.0

    def get_current_speed_display(self) -> str:
        """Get current speed display string."""
        if self.state.sprint_mode:
            return "Sprint"
        elif self.state.is_paused:
            return "Paused"
        elif self.state.speed_multiplier == 1.0:
            return "1x"
        elif self.state.speed_multiplier in [0.5, 2.0, 4.0, 8.0]:
            return f"{self.state.speed_multiplier}x"
        else:
            return f"{self.state.speed_multiplier:.1f}x"

    def _notify_state_change(self):
        """Notify subscribers of state change."""
        if self.event_bus:
            event = Event(
                type=EventType.SIMULATION_STATE_CHANGED,
                data={
                    'timing_state': self.state,
                    'tps': self.state.tps,
                    'is_paused': self.state.is_paused,
                    'sprint_mode': self.state.sprint_mode,
                    'speed_multiplier': self.state.speed_multiplier
                }
            )
            self.event_bus.publish(event)

    def _notify_timing_update(self):
        """Notify subscribers of timing update."""
        if self.event_bus:
            event = Event(
                type=EventType.TIMING_UPDATE,
                data={
                    'actual_tps': self.actual_tps,
                    'total_ticks': self.total_ticks,
                    'tick_counter': self.tick_counter
                }
            )
            self.event_bus.publish(event)