"""JSON-based data store for ticket persistence."""

import json
import os
import threading
from pathlib import Path
from typing import Optional

from models import Ticket

DATA_DIR = Path(__file__).parent / "data"
DATA_FILE = DATA_DIR / "tickets.json"


class TicketStore:
    """Thread-safe JSON-backed ticket store."""

    def __init__(self, filepath: Path = DATA_FILE) -> None:
        self._filepath = filepath
        self._lock = threading.Lock()
        self._next_id = 1
        self._tickets: dict[int, Ticket] = {}
        self._load()

    # ── persistence ──────────────────────────────────────────────

    def _load(self) -> None:
        if not self._filepath.exists():
            self._save()
            return
        with open(self._filepath) as fh:
            raw: list[dict] = json.load(fh)

        self._tickets.clear()
        max_id = 0
        for item in raw:
            ticket = Ticket.from_dict(item)
            self._tickets[ticket.id] = ticket
            if ticket.id and ticket.id > max_id:
                max_id = ticket.id
        self._next_id = max_id + 1

    def _save(self) -> None:
        self._filepath.parent.mkdir(parents=True, exist_ok=True)
        data = [t.to_dict() for t in sorted(self._tickets.values(), key=lambda t: t.id or 0)]
        with open(self._filepath, "w") as fh:
            json.dump(data, fh, indent=2)

    # ── CRUD ─────────────────────────────────────────────────────

    def list_tickets(
        self,
        status: Optional[str] = None,
        priority: Optional[str] = None,
        search: Optional[str] = None,
        project: Optional[str] = None,
    ) -> list[Ticket]:
        tickets = list(self._tickets.values())

        if status:
            tickets = [t for t in tickets if t.status.value == status]
        if priority:
            tickets = [t for t in tickets if t.priority.value == priority]
        if project:
            tickets = [t for t in tickets if t.project.lower() == project.lower()]
        if search:
            q = search.lower()
            tickets = [
                t
                for t in tickets
                if q in t.title.lower()
                or q in t.description.lower()
                or q in t.assignee.lower()
                or q in t.project.lower()
            ]

        return sorted(tickets, key=lambda t: t.id or 0, reverse=True)

    def get_ticket(self, ticket_id: int) -> Optional[Ticket]:
        return self._tickets.get(ticket_id)

    def create_ticket(self, ticket: Ticket) -> Ticket:
        with self._lock:
            ticket.id = self._next_id
            self._next_id += 1
            self._tickets[ticket.id] = ticket
            self._save()
        return ticket

    def update_ticket(self, ticket_id: int, updates: dict) -> Optional[Ticket]:
        ticket = self._tickets.get(ticket_id)
        if ticket is None:
            return None

        with self._lock:
            for key, value in updates.items():
                if hasattr(ticket, key):
                    setattr(ticket, key, value)
            from datetime import datetime, timezone

            ticket.updated_at = datetime.now(timezone.utc).isoformat()
            self._save()
        return ticket

    def delete_ticket(self, ticket_id: int) -> bool:
        with self._lock:
            if ticket_id in self._tickets:
                del self._tickets[ticket_id]
                self._save()
                return True
        return False

    def count_by_status(self) -> dict[str, int]:
        counts: dict[str, int] = {}
        for t in self._tickets.values():
            counts[t.status.value] = counts.get(t.status.value, 0) + 1
        return counts

    def get_projects(self) -> list[str]:
        """Return a sorted list of unique, non-empty project names."""
        projects = {t.project.strip() for t in self._tickets.values() if t.project.strip()}
        return sorted(projects)


# Global singleton store
_store: Optional[TicketStore] = None


def get_store() -> TicketStore:
    global _store
    if _store is None:
        _store = TicketStore()
    return _store