"""
Shared Jinja2 templates configuration.

All routers should import `templates` from this module to get consistent
filter and global function registration.
"""

import json as _json
from fastapi.templating import Jinja2Templates

# Import timezone utilities
from backend.utils.timezone import (
    format_local_datetime, format_local_time,
    get_user_timezone, get_timezone_abbreviation
)


def jinja_local_datetime(dt, fmt="%Y-%m-%d %H:%M"):
    """Jinja filter to convert UTC datetime to local timezone."""
    return format_local_datetime(dt, fmt)


def jinja_local_time(dt):
    """Jinja filter to format time in local timezone."""
    return format_local_time(dt)


def jinja_timezone_abbr():
    """Jinja global to get current timezone abbreviation."""
    return get_timezone_abbreviation()


# Create templates instance
templates = Jinja2Templates(directory="templates")

def jinja_local_date(dt, fmt="%m-%d-%y"):
    """Jinja filter: format a UTC datetime as a local date string (e.g. 02-19-26)."""
    return format_local_datetime(dt, fmt)


def jinja_fromjson(s):
    """Jinja filter: parse a JSON string into a dict (returns {} on failure)."""
    if not s:
        return {}
    try:
        return _json.loads(s)
    except Exception:
        return {}


def jinja_same_date(dt1, dt2) -> bool:
    """Jinja global: True if two datetimes fall on the same local date."""
    if not dt1 or not dt2:
        return False
    try:
        d1 = format_local_datetime(dt1, "%Y-%m-%d")
        d2 = format_local_datetime(dt2, "%Y-%m-%d")
        return d1 == d2
    except Exception:
        return False


# Register Jinja filters and globals
templates.env.filters["local_datetime"] = jinja_local_datetime
templates.env.filters["local_time"] = jinja_local_time
templates.env.filters["local_date"] = jinja_local_date
templates.env.filters["fromjson"] = jinja_fromjson
templates.env.globals["timezone_abbr"] = jinja_timezone_abbr
templates.env.globals["get_user_timezone"] = get_user_timezone
templates.env.globals["same_date"] = jinja_same_date