#!/bin/bash
# 和风天气查询脚本
# 读取 stdin JSON: {"location":"北京","days":3}

read -r input

LOCATION=$(echo "$input" | python3 -c "
import sys, json
d = json.load(sys.stdin)
print(d.get('location', ''))
" 2>/dev/null)

DAYS=$(echo "$input" | python3 -c "
import sys, json
d = json.load(sys.stdin)
print(d.get('days', 3))
" 2>/dev/null)

if [ -z "$LOCATION" ]; then
  echo "请提供 location 参数"
  exit 1
fi

# 从环境变量读取配置
API_HOST="${QWEATHER_API_HOST}"
KEY_ID="${QWEATHER_JWT_KEY_ID}"
PROJECT_ID="${QWEATHER_JWT_PROJECT_ID}"
KEY_FILE="${QWEATHER_JWT_PRIVATE_KEY_FILE:-qweather/ed25519-private.pem}"
TTL="${QWEATHER_JWT_TTL_SECONDS:-3600}"

if [ -z "$API_HOST" ]; then
  echo "请设置 QWEATHER_API_HOST 环境变量"
  exit 1
fi

# 生成 JWT（使用 python3）
JWT=$(python3 -c "
import json, time, base64, struct, sys
from pathlib import Path

key_id = '$KEY_ID'
project_id = '$PROJECT_ID'
key_file = '$KEY_FILE'
ttl = int('$TTL')

if not key_id or not project_id:
    sys.exit(0)

# Read Ed25519 private key
key_path = Path(key_file)
if not key_path.exists():
    sys.exit(0)

key_data = key_path.read_text()

# Simple base64url
def b64url(data):
    return base64.urlsafe_b64encode(data).rstrip(b'=').decode()

# Extract raw key bytes from PEM
import re
pem_match = re.search(r'-----BEGIN PRIVATE KEY-----\\s*(.*?)\\s*-----END PRIVATE KEY-----', key_data, re.DOTALL)
if not pem_match:
    sys.exit(0)

der = base64.b64decode(pem_match.group(1))
# PKCS8 Ed25519 private key: last 32 bytes are the seed
seed = der[-32:]

from hashlib import sha512
h = sha512(seed).digest()
a = bytearray(h[:32])
a[0] &= 248
a[31] &= 127
a[31] |= 64

# Sign using RFC 8032
def ed25519_sign(message, seed_bytes):
    h = sha512(seed_bytes).digest()
    a = bytearray(h[:32])
    a[0] &= 248
    a[31] &= 127
    a[31] |= 64
    r = sha512(bytes(a[32:]) + message).digest()
    R = _sc_reduce(r)
    R_bytes = _sc_mul_base(R)
    S = _sc_add(R, _sc_mul(_sc_reduce(sha512(bytes(R_bytes) + bytes(a) + message).digest()), _sc_reduce(bytes(a))))
    return bytes(R_bytes) + _sc_encode(S)

# Skipping full impl - use openssl instead
print('')
" 2>/dev/null)

# If python3 JWT failed, try openssl
if [ -z "$JWT" ]; then
  NOW=$(date +%s)
  IAT=$((NOW - 30))
  EXP=$((NOW + TTL))

  HEADER=$(echo -n '{"alg":"EdDSA","kid":"'"$KEY_ID"'"}' | base64 -w0 | tr '+/' '-_' | tr -d '=')
  PAYLOAD=$(echo -n '{"sub":"'"$PROJECT_ID"'","iat":'"$IAT"',"exp":'"$EXP"'}' | base64 -w0 | tr '+/' '-_' | tr -d '=')
  SIGNING_INPUT="${HEADER}.${PAYLOAD}"

  # Try openssl pkeyutl (OpenSSL >= 3.0, needs temp file for -rawin)
  TMPFILE=$(mktemp)
  echo -n "$SIGNING_INPUT" > "$TMPFILE"
  SIGNATURE=$(openssl pkeyutl -sign -inkey "$KEY_FILE" -rawin -in "$TMPFILE" 2>/dev/null | base64 -w0 | tr '+/' '-_' | tr -d '=') || true
  rm -f "$TMPFILE"
  if [ -z "$SIGNATURE" ]; then
    # Fallback: try older openssl
    SIGNATURE=$(echo -n "$SIGNING_INPUT" | openssl dgst -sign "$KEY_FILE" -keyform PEM -sha512 2>/dev/null | base64 -w0 | tr '+/' '-_' | tr -d '=') || true
  fi

  if [ -n "$SIGNATURE" ]; then
    JWT="${SIGNING_INPUT}.${SIGNATURE}"
  fi
fi

# Try env var JWT as fallback
if [ -z "$JWT" ]; then
  JWT="${QWEATHER_JWT}"
fi

if [ -z "$JWT" ]; then
  echo "无法生成 QWeather JWT，请检查 QWEATHER_JWT_KEY_ID/QWEATHER_JWT_PROJECT_ID/QWEATHER_JWT_PRIVATE_KEY_FILE 配置"
  exit 1
fi

# 查询城市 ID
CITY_RESP=$(curl -s --compressed "https://geoapi.qweather.com/v2/city/lookup?location=$(echo -n "$LOCATION" | python3 -c "import sys,urllib.parse; print(urllib.parse.quote(sys.stdin.read().strip()))")" -H "Authorization: Bearer $JWT")
CITY_ID=$(echo "$CITY_RESP" | python3 -c "import sys,json; d=json.load(sys.stdin); print(d['location'][0]['id'] if d.get('location') else '')" 2>/dev/null)

if [ -z "$CITY_ID" ]; then
  echo "未找到城市: $LOCATION"
  exit 1
fi

# 查询实况天气
NOW_RESP=$(curl -s --compressed "https://${API_HOST}/v7/weather/now?location=${CITY_ID}&lang=zh&unit=m" -H "Authorization: Bearer $JWT")
NOW_TEMP=$(echo "$NOW_RESP" | python3 -c "import sys,json; d=json.load(sys.stdin); print(f\"{d['now']['temp']}°C, {d['now']['text']}\")" 2>/dev/null)

# 查询预报（最多7天）
ENDPOINT_DAYS=$DAYS
[ "$DAYS" -gt 3 ] && ENDPOINT_DAYS=7
[ "$DAYS" -le 3 ] && ENDPOINT_DAYS=3

DAILY_RESP=$(curl -s --compressed "https://${API_HOST}/v7/weather/${ENDPOINT_DAYS}d?location=${CITY_ID}&lang=zh&unit=m" -H "Authorization: Bearer $JWT")
FORECAST=$(echo "$DAILY_RESP" | python3 -c "
import sys, json
d = json.load(sys.stdin)
days = d.get('daily', [])[:int('$DAYS')]
lines = ['未来天气:']
for day in days:
    lines.append(f\"  {day['fxDate']}: {day['textDay']} {day['tempMin']}~{day['tempMax']}°C\")
print('\\n'.join(lines))
" 2>/dev/null)

echo "${LOCATION}天气: 当前 ${NOW_TEMP}"
echo ""
echo "$FORECAST"