from __future__ import annotations

import json
import re
import unicodedata
from dataclasses import dataclass
from datetime import date, timedelta
from pathlib import Path

from .config import ROOT, client_dir
from .history import now_local
from .table import print_table


GLOBAL_REMINDERS_PATH = ROOT / "reminders.jsonl"


@dataclass(frozen=True)
class Reminder:
    id: str
    created_at: str
    due_date: str
    text: str
    client: str
    status: str

    @classmethod
    def from_dict(cls, data: dict) -> "Reminder":
        return cls(
            id=str(data.get("id", "")),
            created_at=str(data.get("created_at", "")),
            due_date=str(data.get("due_date", "")),
            text=str(data.get("text", "")),
            client=str(data.get("client", "")),
            status=str(data.get("status", "active")),
        )

    def to_dict(self) -> dict:
        return {
            "id": self.id,
            "created_at": self.created_at,
            "due_date": self.due_date,
            "text": self.text,
            "client": self.client,
            "status": self.status,
        }


def normalize_text(value: str) -> str:
    normalized = unicodedata.normalize("NFKD", value)
    without_marks = "".join(ch for ch in normalized if not unicodedata.combining(ch))
    return without_marks.lower()


def reminder_path(domain: str | None = None) -> Path:
    if domain:
        base = client_dir(domain)
        return base / "reminders.jsonl"
    return GLOBAL_REMINDERS_PATH


def load_reminders(domain: str | None = None, include_global: bool = False) -> list[Reminder]:
    paths = []
    if include_global:
        paths.append(GLOBAL_REMINDERS_PATH)
    paths.append(reminder_path(domain))
    reminders: list[Reminder] = []
    for path in paths:
        if not path.exists():
            continue
        for line in path.read_text(encoding="utf-8").splitlines():
            if not line.strip():
                continue
            try:
                reminders.append(Reminder.from_dict(json.loads(line)))
            except json.JSONDecodeError:
                continue
    reminders.sort(key=lambda item: (item.due_date, item.created_at, item.id))
    return reminders


def parse_reminder_text(raw_text: str) -> tuple[date, str]:
    text = " ".join(raw_text.split()).strip()
    if not text:
        raise ValueError("Brak tresci przypomnienia.")

    today = now_local().date()
    normalized = normalize_text(text)
    due = today
    matched_prefix = ""

    patterns = [
        (r"^za\s+(\d+)\s+dni(?:\s+|$)", "days"),
        (r"^za\s+(\d+)\s+dzien(?:\s+|$)", "days"),
        (r"^za\s+(\d+)\s+tygodnie(?:\s+|$)", "weeks"),
        (r"^za\s+(\d+)\s+tygodni(?:\s+|$)", "weeks"),
        (r"^za\s+(\d+)\s+tydzien(?:\s+|$)", "weeks"),
        (r"^za\s+(\d+)\s+miesiace(?:\s+|$)", "months"),
        (r"^za\s+(\d+)\s+miesiecy(?:\s+|$)", "months"),
        (r"^za\s+(\d+)\s+miesiac(?:\s+|$)", "months"),
    ]
    for pattern, unit in patterns:
        match = re.search(pattern, normalized)
        if not match:
            continue
        amount = int(match.group(1))
        if unit == "days":
            due = today + timedelta(days=amount)
        elif unit == "weeks":
            due = today + timedelta(weeks=amount)
        else:
            due = today + timedelta(days=amount * 30)
        matched_prefix = text[: match.end()].strip()
        break

    if not matched_prefix:
        if normalized.startswith("jutro"):
            due = today + timedelta(days=1)
            matched_prefix = text[:5].strip()
        elif normalized.startswith("dzisiaj"):
            due = today
            matched_prefix = text[:7].strip()

    note = text[len(matched_prefix) :].strip() if matched_prefix else text
    note_normalized = normalize_text(note)
    for prefix in [
        "przypomnij mi o ",
        "przypomnij o ",
        "przypomnienie o ",
        "o ",
    ]:
        if note_normalized.startswith(prefix):
            note = note[len(prefix) :].strip()
            break
    if not note:
        note = text
    return due, note


def add_reminder(raw_text: str, domain: str | None = None) -> Reminder:
    due, note = parse_reminder_text(raw_text)
    ts = now_local()
    reminder = Reminder(
        id=f"rem_{ts.strftime('%Y%m%d%H%M%S')}",
        created_at=ts.isoformat(timespec="seconds"),
        due_date=due.isoformat(),
        text=note,
        client=domain or "",
        status="active",
    )
    path = reminder_path(domain)
    path.parent.mkdir(parents=True, exist_ok=True)
    with path.open("a", encoding="utf-8") as f:
        f.write(json.dumps(reminder.to_dict(), ensure_ascii=False) + "\n")
    return reminder


def active_reminders_for_client(domain: str) -> list[Reminder]:
    return [item for item in load_reminders(domain, include_global=True) if item.status == "active"]


def reminder_status_label(reminder: Reminder) -> str:
    today = now_local().date()
    try:
        due = date.fromisoformat(reminder.due_date)
    except ValueError:
        return "brak daty"
    days = (due - today).days
    if days < 0:
        return f"po terminie {abs(days)} dni"
    if days == 0:
        return "dzisiaj"
    if days == 1:
        return "jutro"
    return f"za {days} dni"


def print_client_reminders(domain: str, limit: int = 12) -> None:
    reminders = active_reminders_for_client(domain)
    if not reminders:
        return
    print("\nPrzypomnienia")
    shown = reminders[:limit]
    print_table(
        ["Termin", "Status", "Zakres", "Notatka"],
        [
            [
                reminder.due_date,
                reminder_status_label(reminder),
                reminder.client or "globalne",
                reminder.text,
            ]
            for reminder in shown
        ],
    )
    if len(reminders) > len(shown):
        print(f"... oraz {len(reminders) - len(shown)} kolejnych przypomnien")