#!/bin/bash
# Google Calendar Birthday Sync
# Fetches iCal feed, extracts birthdays, syncs with birthdays.json
# Runs daily alongside birthday-tracker

set -e

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "$SCRIPT_DIR/../../.env" 2>/dev/null || true

# Config
ICAL_URL="${GOOGLE_CALENDAR_ICAL:-https://calendar.google.com/calendar/ical/anthonymau%40gmail.com/private-3636d9c51e7beda202676124684619ad/basic.ics}"
BIRTHDAY_DATA="$SCRIPT_DIR/../birthday-tracker/birthdays.json"
TELEGRAM_CHAT="${TELEGRAM_CHAT:-1793951355}"
NTFY_URL="${NTFY_URL:-}"
NTFY_TOPIC="${NTFY_TOPIC:-}"
NTFY_MIN_PRIORITY="${NTFY_MIN_PRIORITY:-4}"
TEMP_ICS="/tmp/gcal-birthdays.ics"

log() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1"
}

# Fetch iCal feed
fetch_ical() {
    log "Fetching Google Calendar iCal feed..."
    curl -s "$ICAL_URL" -o "$TEMP_ICS" || {
        log "ERROR: Failed to fetch iCal feed"
        return 1
    }
    log "Fetched $(wc -l < "$TEMP_ICS") lines"
}

# Parse birthdays from iCal using Python
parse_birthdays() {
    python3 << 'EOF' - "$TEMP_ICS" "$BIRTHDAY_DATA"
import sys
import json
import re
from datetime import datetime
from icalendar import Calendar

ics_path = sys.argv[1]
data_path = sys.argv[2]

# Load existing birthdays data
with open(data_path, 'r') as f:
    data = json.load(f)

existing_names = {p['name'].lower() for p in data['people']}
new_birthdays = []

# Parse iCal
with open(ics_path, 'rb') as f:
    cal = Calendar.from_ical(f.read())

for event in cal.walk('VEVENT'):
    summary = str(event.get('summary', ''))
    
    # Check if this looks like a birthday event
    if not re.search(r'\bbirthday\b', summary, re.IGNORECASE):
        continue
    
    # Extract name (remove "birthday" and common suffixes)
    name = re.sub(r'\s*(?:\'s|\s)?\s*birthday.*$', '', summary, flags=re.IGNORECASE).strip()
    name = re.sub(r'^(?:buy|get)\s+', '', name, flags=re.IGNORECASE).strip()
    name = name.replace("'s", "").strip()
    
    # Skip if already tracked or empty
    if not name or name.lower() in existing_names:
        continue
    
    # Get date
    dtstart = event.get('dtstart')
    if dtstart:
        dt = dtstart.dt
        if hasattr(dt, 'month') and hasattr(dt, 'day'):
            # Handle both date and datetime
            month = dt.month
            day = dt.day
            birth_year = dt.year if hasattr(dt, 'year') and dt.year > 1900 else None
        else:
            continue
    else:
        continue
    
    # Format birthday as MM-DD
    birthday = f"{month:02d}-{day:02d}"
    
    new_person = {
        "name": name,
        "relationship": "Contact (from Google Calendar)",
        "birthday": birthday,
        "source": "google-calendar",
        "gift_ideas": [],
        "past_gifts": [],
        "notes": f"Found in Google Calendar: {summary}"
    }
    
    if birth_year:
        new_person["birth_year"] = birth_year
    
    new_birthdays.append(new_person)
    print(f"Found: {name} - {birthday}", file=sys.stderr)

# Output as JSON
print(json.dumps(new_birthdays, indent=2))
EOF
}

# Merge new birthdays into existing data
merge_birthdays() {
    local new_birthdays="$1"
    local count=$(echo "$new_birthdays" | jq 'length')
    
    if ((count == 0)); then
        log "No new birthdays found"
        return 0
    fi
    
    log "Merging $count new birthdays..."
    
    # Add to existing data
    local temp_file=$(mktemp)
    jq --argjson new "$new_birthdays" '.people += $new' "$BIRTHDAY_DATA" > "$temp_file"
    mv "$temp_file" "$BIRTHDAY_DATA"
    
    log "Updated birthday database with $count new entries"
    
    # Send notification
    local names=$(echo "$new_birthdays" | jq -r '.[].name' | tr '\n' ', ' | sed 's/, $//')
    local message="📅 *Google Calendar Sync*\n\nFound and added *$count* new birthdays:\n$names\n\nThese will now be included in your birthday reminders!"
    
    # Telegram
    curl -s -X POST "https://api.telegram.org/bot${TELEGRAM_BOT_TOKEN}/sendMessage" \
        -H "Content-Type: application/json" \
        -d "{\"chat_id\": \"$TELEGRAM_CHAT\", \"text\": \"$message\", \"parse_mode\": \"Markdown\"}" > /dev/null || true
    
    # ntfy
    if [[ -n "${NTFY_URL:-}" && -n "${NTFY_TOPIC:-}" ]]; then
        curl -s -X POST "${NTFY_URL%/}/${NTFY_TOPIC}" \
            -H "Title: Birthday Sync" \
            -H "Priority: ${NTFY_MIN_PRIORITY:-4}" \
            -H "Sound: default" \
            -d "Added $count new birthdays from Google Calendar: $names" > /dev/null 2>&1 || true
    fi
}

# Show current stats
show_stats() {
    local total=$(jq '.people | length' "$BIRTHDAY_DATA")
    local gcal=$(jq '[.people[] | select(.source == "google-calendar")] | length' "$BIRTHDAY_DATA")
    local manual=$((total - gcal))
    
    log "Birthday database stats:"
    log "  Total: $total people"
    log "  Manual entries: $manual"
    log "  From Google Calendar: $gcal"
}

# Cleanup
cleanup() {
    rm -f "$TEMP_ICS"
}

# Main
main() {
    trap cleanup EXIT
    
    log "Starting Google Calendar birthday sync..."
    
    fetch_ical
    
    local new_birthdays
    new_birthdays=$(parse_birthdays)
    
    merge_birthdays "$new_birthdays"
    show_stats
    
    log "Sync complete!"
}

main "$@"