from __future__ import annotations

from dataclasses import dataclass, asdict
from datetime import datetime
from pathlib import Path
import json
import re

from .types import PatternParameters


@dataclass
class PresetRecord:
    name: str
    pattern_id: str
    parameters: dict
    brightness: float
    palette: str
    created_at: str
    tempo_bpm: float | None = None

    @classmethod
    def create(cls, name: str, pattern_id: str, params: PatternParameters, tempo_bpm: float | None = None) -> "PresetRecord":
        return cls(
            name=name,
            pattern_id=pattern_id,
            parameters=params.to_dict(),
            brightness=params.brightness,
            palette=params.palette,
            created_at=datetime.utcnow().isoformat(timespec="seconds"),
            tempo_bpm=tempo_bpm,
        )


class PresetStore:
    def __init__(self, root: str | Path) -> None:
        self.root = Path(root)
        self.root.mkdir(parents=True, exist_ok=True)

    def list_presets(self) -> list[PresetRecord]:
        presets: list[PresetRecord] = []
        for path in sorted(self.root.glob("*.json")):
            try:
                payload = json.loads(path.read_text(encoding="utf-8"))
                presets.append(PresetRecord(**payload))
            except (OSError, json.JSONDecodeError, TypeError):
                continue
        return presets

    def save(self, record: PresetRecord) -> Path:
        path = self.root / f"{slugify(record.name)}.json"
        path.write_text(json.dumps(asdict(record), indent=2), encoding="utf-8")
        return path

    def load(self, name: str) -> PresetRecord:
        path = self.root / f"{slugify(name)}.json"
        payload = json.loads(path.read_text(encoding="utf-8"))
        return PresetRecord(**payload)

    def delete(self, name: str) -> None:
        path = self.root / f"{slugify(name)}.json"
        if path.exists():
            path.unlink()

    def ensure_seed_presets(self) -> None:
        if any(self.root.glob("*.json")):
            return
        seeds = [
            PresetRecord.create(
                "Afterhours Pulse",
                "center_pulse",
                PatternParameters(palette="Afterhours", color_mode="palette", fade=0.28),
            ),
            PresetRecord.create(
                "Laser Chase",
                "scan_dual",
                PatternParameters(palette="Laser Club", block_size=1.6, direction="left_to_right"),
            ),
            PresetRecord.create(
                "Heat Breathing",
                "breathing",
                PatternParameters(palette="Warehouse Heat", color_mode="palette", fade=0.7),
            ),
        ]
        for preset in seeds:
            self.save(preset)


def slugify(value: str) -> str:
    return re.sub(r"[^a-z0-9]+", "-", value.lower()).strip("-") or "preset"