"""
OpenEnv - Production-Ready Reinforcement Learning Environment

A Gymnasium-compatible environment implementing the standard step(), reset(), 
and state() API for AI agent training in an Email Triage Task.
"""

import numpy as np
from typing import Tuple, Optional, Dict, Any, Union, List
import gymnasium as gym
from gymnasium import spaces
import logging
import time
import random

from openenv.core.config import EnvConfig
from openenv.core.models import Observation, Action, Reward, Email, EnvState


def _generate_email(email_id: int, task_level: str, spam_ratio: float, urgent_ratio: float, confounding_ratio: float) -> Email:
    """Generate a random Email object for triage based on probability ratios."""
    is_spam = random.random() < spam_ratio
    is_urgent = False if is_spam else random.random() < urgent_ratio
    is_confusing = False
    is_internal = False
    
    if task_level in ['medium', 'hard']:
        is_confusing = random.random() < confounding_ratio
        
    if is_spam:
        sender = f"spammer{random.randint(1,999)}@shady-deals.com"
        subject = "You Won $1,000,000!" if not is_confusing else "Invoice #91823 Overdue"
        body = "Click here to claim your prize." if not is_confusing else "Please review the attached invoice urgently to avoid account suspension."
        is_internal = False
    elif is_urgent:
        sender = "boss@company.com"
        subject = "URGENT: Project deadline!" if not is_confusing else "Update?"
        body = "We need the final report ASAP. Forward it to the team." if not is_confusing else "Are we on track? Let me know."
        is_internal = True
    else:
        is_internal = random.random() < 0.8
        if is_internal:
            sender = f"colleague_{random.randint(1,50)}@company.com"
            subject = "Lunch later?" if not is_confusing else "Git merge conflict"
            body = "I'm heading out at 12." if not is_confusing else "I think there is an issue with the latest PR, can you reply with your thoughts?"
        else:
            sender = "newsletter@techweekly.com"
            subject = "This week in Tech"
            body = "Here are the top 10 trends you need to know."
            
    # For Hard tasks, inject random noise
    if task_level == 'hard' and random.random() < 0.2:
        subject = subject.upper() if random.random() < 0.5 else subject.lower()
        body += "\n\n" + " ".join([chr(random.randint(97, 122)) for _ in range(20)])
        
    return Email(
        id=f"email_{email_id}",
        sender=sender,
        subject=subject,
        body=body,
        is_urgent=is_urgent,
        is_spam=is_spam,
        is_internal=is_internal
    )


class OpenEnv(gym.Env):
    """
    Email Triage Environment.
    
    Agent must read incoming emails and perform one of the actions:
    0 = Ignore
    1 = Reply
    2 = Forward
    3 = Archive
    4 = Delete
    
    Observation Space: Continuous remaining count and discrete current_email attributes.
    Action Space: Discrete(5)
    """
    
    metadata = {
        'render_modes': ['human'],
        'render_fps': 1,
    }
    
    def __init__(
        self,
        config: Optional[EnvConfig] = None,
        render_mode: Optional[str] = None,
    ):
        super().__init__()
        
        # Configuration
        self.config = config if config is not None else EnvConfig()
        self.config.validate()
        
        if render_mode is not None:
            self.config.render_mode = render_mode
            
        if self.config.random_seed is not None:
            self.seed(self.config.random_seed)
            
        self._setup_logging()
        
        # Action space: 5 discrete actions
        self.action_space = spaces.Discrete(5)
        
        # Simple array observation space backing the gym interface
        # [emails_remaining, is_spam, is_urgent, is_internal]
        self.observation_space = spaces.Box(
            low=0.0, high=float('inf'), shape=(4,), dtype=np.float32
        )
        
        # State
        self.emails_queue: List[Email] = []
        self.current_email_index: int = 0
        self.total_reward: float = 0.0
        self.start_time: float = 0.0
        self.metrics: Dict[str, Any] = {}
        
        self.logger.info("Email Triage OpenEnv initialized.")
        
    def _setup_logging(self) -> None:
        self.logger = logging.getLogger('OpenEnv')
        self.logger.setLevel(logging.INFO if self.config.verbose else logging.WARNING)
        if not self.logger.handlers:
            handler = logging.StreamHandler()
            formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
            handler.setFormatter(formatter)
            self.logger.addHandler(handler)
            
    def _generate_inbox(self):
        """Generate a new batch of emails for the episode."""
        self.emails_queue = [
            _generate_email(
                i, 
                self.config.task_level, 
                self.config.spam_ratio, 
                self.config.urgent_ratio, 
                self.config.confounding_ratio
            )
            for i in range(self.config.num_emails)
        ]
        
    def reset(
        self,
        seed: Optional[int] = None,
        options: Optional[Dict[str, Any]] = None,
    ) -> Tuple[Observation, Dict[str, Any]]:
        
        if seed is not None:
            self.np_random, seed = gym.utils.seeding.np_random(seed)
            random.seed(seed)
            
        self._generate_inbox()
        self.current_email_index = 0
        self.total_reward = 0.0
        self.start_time = time.time()
        
        self.metrics = {
            'correct_actions': 0,
            'incorrect_actions': 0,
            'critical_failures': 0,
            'steps': 0
        }
        
        obs = self.get_observation_model()
        return obs, self.metrics
    
    def _evaluate_action(self, action_type: int, email: Email) -> Tuple[float, str, bool]:
        """
        Evaluate if the action was appropriate for the email.
        Action Map: 0: Ignore, 1: Reply, 2: Forward, 3: Archive, 4: Delete
        
        Returns: (reward, feedback_message, is_correct)
        """
        # Define Ground Truth logic
        if email.is_spam:
            expected = 4 # Delete
        elif email.is_urgent:
            expected = 2 if "forward" in email.body.lower() else 1 # Forward or Reply
        elif email.is_internal:
            expected = 1 if "?" in email.body else 3 # Reply if question, else Archive
        else:
            expected = 3 # Archive newsletter/generic
            
        is_correct = action_type == expected
        reward = 1.0 if is_correct else -1.0
        message = "Correctly triaged." if is_correct else f"Incorrect. Ground Truth action was {expected}."
        
        # Critical failures
        if email.is_urgent and action_type in [0, 4]: # Ignoring or deleting urgent mail
            reward = -5.0
            message = "CRITICAL FAILURE: Deleted or ignored urgent email!"
            self.metrics['critical_failures'] += 1
            
        if email.is_spam and action_type in [1, 2]: # Replying/Forwarding spam
            reward = -2.0
            message = "FAILURE: Engaged with spam!"
            
        return reward * self.config.reward_scale, message, is_correct

    def step(self, action: Union[Action, int]) -> Tuple[Observation, float, bool, bool, Dict[str, Any]]:
        # Gym support
        if isinstance(action, Action):
            act_val = action.action_type
        else:
            act_val = int(action)
            
        if self.current_email_index >= len(self.emails_queue):
            return self.get_observation_model(), 0.0, True, False, self.metrics
            
        current_email = self.emails_queue[self.current_email_index]
        self.metrics['steps'] += 1
        
        # Evaluate
        step_rew, msg, is_correct = self._evaluate_action(act_val, current_email)
        self.total_reward += step_rew
        
        if is_correct:
            self.metrics['correct_actions'] += 1
        else:
            self.metrics['incorrect_actions'] += 1
            
        self.metrics['last_reward_msg'] = msg
        self.metrics['last_reward'] = step_rew
        
        self.current_email_index += 1
        
        terminated = self.current_email_index >= len(self.emails_queue)
        truncated = False
        
        obs = self.get_observation_model()
        
        return obs, float(step_rew), terminated, truncated, self.metrics
        
    def get_observation_model(self) -> Observation:
        remaining = len(self.emails_queue) - self.current_email_index
        current_email = self.emails_queue[self.current_email_index] if remaining > 0 else None
        elapsed = time.time() - self.start_time
        
        return Observation(
            emails_remaining=remaining,
            current_email=current_email,
            time_elapsed=elapsed
        )
        
    def state(self) -> EnvState:
        """Returns the full strictly-typed Pydantic EnvState."""
        obs = self.get_observation_model()
        rew = Reward(
            step_reward=self.metrics.get('last_reward', 0.0),
            total_reward=self.total_reward,
            message=self.metrics.get('last_reward_msg', "")
        )
        term = self.current_email_index >= len(self.emails_queue)
        return EnvState(
            observation=obs,
            reward=rew,
            terminated=term,
            truncated=False,
            info=self.metrics
        )
        
    def render(self) -> None:
        if self.config.render_mode != 'human':
            return
            
        obs = self.get_observation_model()
        print(f"\n[{obs.emails_remaining} Emails Remaining] Total Reward: {self.total_reward:.1f}")
        if obs.current_email:
            print("="*40)
            print(f"From:    {obs.current_email.sender}")
            print(f"Subject: {obs.current_email.subject}")
            print("-" * 40)
            print(f"{obs.current_email.body}")
            print("="*40)
            print("Actions: 0=Ignore, 1=Reply, 2=Forward, 3=Archive, 4=Delete")

    def close(self) -> None:
        pass
        
    def seed(self, seed: Optional[int] = None) -> int:
        if seed is None:
            seed = int(time.time() * 1000) % 2**31
        self.np_random, seed = gym.utils.seeding.np_random(seed)
        random.seed(seed)
        self.config.random_seed = seed
        return seed