"""
tasks/task_registry.py — Central task registry.

All 9 tasks indexed by ID and difficulty. sample_task() picks randomly
within a difficulty tier to prevent memorisation across episodes.
"""
import random
from typing import Dict, Any

from tasks.easy.password_validator import TASK as T1
from tasks.easy.input_sanitizer import TASK as T2
from tasks.easy.hash_generator import TASK as T3
from tasks.medium.sql_query_builder import TASK as T4
from tasks.medium.file_path_handler import TASK as T5
from tasks.medium.api_rate_limiter import TASK as T6
from tasks.hard.file_upload_handler import TASK as T7
from tasks.hard.jwt_validator import TASK as T8
from tasks.hard.auth_middleware import TASK as T9

ALL_TASKS: Dict[str, Dict[str, Any]] = {
    t["id"]: t for t in [T1, T2, T3, T4, T5, T6, T7, T8, T9]
}

BY_DIFFICULTY = {
    "easy":   [T1, T2, T3],
    "medium": [T4, T5, T6],
    "hard":   [T7, T8, T9],
}


def get_task(task_id: str) -> Dict[str, Any]:
    if task_id not in ALL_TASKS:
        raise ValueError(f"Unknown task_id: {task_id}. Valid: {list(ALL_TASKS.keys())}")
    return ALL_TASKS[task_id]


def sample_task(difficulty: str = "medium") -> Dict[str, Any]:
    """Randomly pick a task at the given difficulty. Anti-memorisation."""
    tasks = BY_DIFFICULTY.get(difficulty, BY_DIFFICULTY["medium"])
    return random.choice(tasks)


def list_tasks() -> list:
    return [
        {
            "id": t["id"],
            "difficulty": t["difficulty"],
            "cwe_targets": t["cwe_targets"],
        }
        for t in ALL_TASKS.values()
    ]