"""Choose largest number out of several represented in various formats."""

from dataclasses import dataclass
from random import Random
from typing import Any, Optional

from ..coaching import BaseCurriculum, RangeAttributeDefinition, ScalarAttributeDefinition
from ..factory import ProceduralDataset, register_dataset

QUESTION_TEMPLATE = """Your task is to pick the largest/smallest number out of several options.

Your output should be only the number of interest.

Now, pick the {size} number of the following candidates: {numbers}
"""


@dataclass
class NumberFormatConfig:
    """Configuration for Count Bits dataset generation"""

    min_num_candidates: int = 2  # Minimum number of candidates
    max_num_candidates: int = 5  # Maximum number of candidates
    min_n: float = 1_000  # Lower bound for the numbers
    max_n: float = 1_000_000_000  # Upper bound for the numbers
    max_delta: float = 10.0

    size: int = 500  # Virtual dataset size
    seed: Optional[int] = None

    def validate(self):
        """Validate configuration parameters"""
        assert 2 <= self.min_num_candidates, "min_num_candidates must be at least 2"
        assert (
            self.min_num_candidates <= self.max_num_candidates
        ), "min_num_candidates must be less than max_num_candidates"
        assert 1 <= self.min_n, "min_n must be at least 1"
        assert self.min_n < self.max_n, "min_n must be less than max_n"
        assert 0 < self.max_delta, "max_delta must be greater than 0"


class NumberFormatDataset(ProceduralDataset):
    """Generates Count Bits exercises with configurable difficulty"""

    def __init__(self, config: NumberFormatConfig):
        super().__init__(config=config, seed=config.seed, size=config.size)

    def _get_candidates(self, rng: Random, num_candidates: int) -> list:
        """Generate a list of candidates"""
        base = round(rng.uniform(self.config.min_n, self.config.max_n), 3)
        candidates = [base]
        for _ in range(num_candidates - 1):
            delta = round(rng.uniform(-self.config.max_delta, self.config.max_delta), 3)
            candidates.append(base + delta)
        return candidates

    def _transform_candidates(self, rng: Random, candidates: list[float]) -> list[str]:
        """Randomly apply different number formats to the candidates"""
        output = []
        for candidate in candidates:
            format_type = rng.choice(["standard", "english", "scientific"])
            if format_type == "standard":
                output.append(f"{candidate:f}")
            elif format_type == "english":
                output.append(f"{candidate:,}")
            elif format_type == "scientific":
                output.append(f"{candidate:.15e}")
        return output

    def score_answer(self, answer: Optional[str], entry: dict[str, Any]) -> float:
        """Overwrite this method in derived classes if a single oracle answer is not available."""
        oracle_answer = entry["metadata"]["solution"]
        if isinstance(answer, str) and len(answer) > 0:
            try:
                answer = float(answer.strip().replace(",", ""))
                if abs(answer - oracle_answer) < 1e-2:
                    return 1.0
            except:
                pass
        return 0.0

    def __getitem__(self, idx: int) -> dict:
        """Generate a single Count Bits question"""
        rng = Random(self.seed + idx)

        num_candidates = rng.randint(self.config.min_num_candidates, self.config.max_num_candidates)
        candidates = self._get_candidates(rng, num_candidates)
        formatted_candidates = self._transform_candidates(rng, candidates)

        size = rng.choice(["largest", "smallest"])
        answer = max(candidates) if size == "largest" else min(candidates)

        return {
            "question": QUESTION_TEMPLATE.format(numbers=" ".join(formatted_candidates), size=size),
            "answer": str(answer),
            "metadata": {
                "candidates": candidates,
                "solution": answer,
                "formatted_candidates": formatted_candidates,
                "size": size,
                "num_candidates": num_candidates,
                "difficulty": {
                    "num_candidates": (self.config.min_num_candidates, self.config.max_num_candidates),
                    "n": (self.config.min_n, self.config.max_n),
                    "min_delta": self.config.max_delta,
                },
            },
        }


class NumberFormatCurriculum(BaseCurriculum):
    def __init__(self):
        super().__init__(NumberFormatCurriculum.__name__, NumberFormatConfig)

        self._define_attributes(
            RangeAttributeDefinition(
                name="num_candidates",
                levels=[5, 25, 100, 500],
                description="Number of candidates",
                lower_field_name="min_num_candidates",
                upper_field_name="max_num_candidates",
                ensure_interval=True,
            ),
            RangeAttributeDefinition(
                name="n",
                levels=[10, 1_000, 1_000_000, 1_000_000_000],
                description="Magnitude of the values",
                lower_field_name="min_n",
                upper_field_name="max_n",
                ensure_interval=True,
            ),
            ScalarAttributeDefinition(
                name="max_delta",
                field_name="max_delta",
                levels=[1e1, 1e0, 1e-3, 1e-6],
                description="Max delta",
            ),
        )


register_dataset("number_format", NumberFormatDataset, NumberFormatConfig, NumberFormatCurriculum)