# utils/csv_utils.py — CSV read/write/export for city labels
import os
import csv
import tempfile
from typing import Dict

from config import ASSETS_DIR, DIST_MIN, DIST_MAX

try:
    import gradio as gr
except ImportError:
    gr = None


def _read_all_cities_csv(csv_path: str):
    with open(csv_path, "r", encoding="utf-8-sig") as f:
        rdr = csv.DictReader(f)
        rows = list(rdr)
        fieldnames = list(rdr.fieldnames or [])
    return rows, fieldnames


def _write_all_cities_csv(csv_path: str, rows, fieldnames):
    with open(csv_path, "w", encoding="utf-8-sig", newline="") as f:
        w = csv.DictWriter(f, fieldnames=fieldnames)
        w.writeheader()
        for r in rows:
            w.writerow({k: r.get(k, "") for k in fieldnames})


def save_label_for_city_to_csv(city_name: str, ang: float, dist: float):
    if not city_name:
        if gr:
            try:
                gr.Info("Chua chon dia danh.")
            except Exception:
                pass
        return
    csv_path = os.path.join(ASSETS_DIR, "cities_custom.csv")
    if not os.path.exists(csv_path):
        if gr:
            try:
                gr.Warning("Chua co assets/cities_custom.csv.")
            except Exception:
                pass
        return

    rows, fns = _read_all_cities_csv(csv_path)
    for col in ("label_ang", "label_dist"):
        if col not in fns:
            fns.append(col)

    found = False
    for r in rows:
        if (r.get("name", "") or "").strip() == city_name.strip():
            r["label_ang"] = f"{float(ang):.2f}"
            r["label_dist"] = f"{float(dist):.2f}"
            found = True
            break

    if not found:
        if gr:
            try:
                gr.Warning(f"Khong thay '{city_name}' trong cities_custom.csv.")
            except Exception:
                pass
        return

    _write_all_cities_csv(csv_path, rows, fns)

    # Reload DB
    from models.city import CityDB
    import models.city as mc
    mc.DB = CityDB()
    mc.ALL_CITIES = sorted(mc.DB.by_name.keys())


def export_cities_csv_with_labels(label_overrides: Dict[str, Dict[str, float]]):
    csv_path = os.path.join(ASSETS_DIR, "cities_custom.csv")
    rows = []
    fns = ["name", "lat", "lon", "country", "aliases", "label_ang", "label_dist"]
    if os.path.exists(csv_path):
        with open(csv_path, "r", encoding="utf-8-sig") as f:
            rdr = csv.DictReader(f)
            rows = list(rdr)
            fns = list(dict.fromkeys(list(rdr.fieldnames or []) + ["label_ang", "label_dist"]))

    idx = {(r.get("name", "") or "").strip(): r for r in rows}
    for nm, cfg in (label_overrides or {}).items():
        if nm in idx and isinstance(cfg, dict):
            if "ang" in cfg and cfg["ang"] is not None:
                idx[nm]["label_ang"] = f"{float(cfg['ang']):.2f}"
            if "dist" in cfg and cfg["dist"] is not None:
                idx[nm]["label_dist"] = f"{float(cfg['dist']):.2f}"

    out_path = os.path.join(tempfile.gettempdir(), "cities_custom.csv")
    with open(out_path, "w", encoding="utf-8-sig", newline="") as f:
        w = csv.DictWriter(f, fieldnames=fns)
        w.writeheader()
        for r in rows:
            w.writerow({k: r.get(k, "") for k in fns})
    return out_path