import os
import socket
import json
from hashlib import sha256 as hashlib_sha256
import base58
from flask import Flask, jsonify, request
from bitcoinlib.services.bitcoind import BitcoindClient
from dotenv import load_dotenv

load_dotenv()

app = Flask(__name__)

RPC_USER = os.getenv('RPC_USER')
RPC_PASS = os.getenv('RPC_PASS')
IP_ADRESSE   = '192.168.178.225'   # ← Docker-Servicename statt IP
ELECTRS_HOST = '192.168.178.225'    # ← Docker-Servicename statt IP
ELECTRS_PORT = 50001

if not RPC_USER or not RPC_PASS:
    raise ValueError("Fehler: RPC_USER oder RPC_PASS wurden nicht in der Umgebung gefunden!")

rpc_url = f'http://{RPC_USER}:{RPC_PASS}@192.168.178.225:8332'

def get_node():
    return BitcoindClient(network='bitcoin', base_url=rpc_url).proxy

# ==========================================
# ELECTRS HILFSFUNKTIONEN
# ==========================================
def address_to_script(address: str) -> str:
    """Konvertiert Bitcoin-Adresse → Output-Script (hex)"""
    if address.startswith("bc1"):
        # P2WPKH / P2WSH (bech32)
        # Manuell dekodieren ohne externe bech32-Library
        import bech32
        witver, witprog = bech32.decode("bc", address)
        if witprog is None:
            raise ValueError(f"Ungültige bech32-Adresse: {address}")
        if len(witprog) == 20:
            return "0014" + bytes(witprog).hex()  # P2WPKH
        return "0020" + bytes(witprog).hex()       # P2WSH

    decoded = base58.b58decode_check(address)
    prefix  = decoded[0]
    payload = decoded[1:].hex()

    if prefix == 0x00:    # 1... → P2PKH
        return f"76a914{payload}88ac"
    elif prefix == 0x05:  # 3... → P2SH
        return f"a914{payload}87"

    raise ValueError(f"Unbekanntes Adressformat: {address}")

def address_to_electrum_hash(address: str) -> str:
    """Berechnet den Electrum script_hash für eine Adresse"""
    script = bytes.fromhex(address_to_script(address))
    return hashlib_sha256(script).digest()[::-1].hex()

def electrs_query(method: str, params: list):
    """Sendet eine Anfrage an den lokalen Electrs-Server"""
    req = json.dumps({"id": 1, "method": method, "params": params}) + "\n"
    with socket.create_connection((ELECTRS_HOST, ELECTRS_PORT), timeout=10) as s:
        s.sendall(req.encode())
        data = b""
        while True:
            chunk = s.recv(4096)
            data += chunk
            if b"\n" in chunk:
                break
    result = json.loads(data.decode())
    if "error" in result and result["error"]:
        raise Exception(f"Electrs Fehler: {result['error']}")
    return result["result"]

# ==========================================
# ENDPUNKT 1: Aktuelle Blockhöhe abfragen
# ==========================================
@app.route('/api/blockhoehe', methods=['GET'])
def get_blockhoehe():
    try:
        node = get_node()
        info = node.getblockchaininfo()
        return jsonify({
            'status': 'success',
            'blockhoehe': info['blocks'],
            'sync_fortschritt_prozent': round(info.get('verificationprogress', 0) * 100, 2)
        })
    except Exception as e:
        return jsonify({'status': 'error', 'message': str(e)}), 500

# ==========================================
# ENDPUNKT 2: Bestimmten Block abfragen
# ==========================================
@app.route('/api/block/<int:hoehe>', methods=['GET'])
def get_block(hoehe):
    try:
        node = get_node()
        block_hash = node.getblockhash(hoehe)
        block_daten = node.getblock(block_hash, 2)
        return jsonify({'status': 'success', 'block': block_daten})
    except Exception as e:
        return jsonify({'status': 'error', 'message': str(e)}), 500

# ==========================================
# ENDPUNKT 3: Einzelne Transaktion abfragen
# ==========================================
@app.route('/api/tx/<txid>', methods=['GET'])
def get_tx(txid):
    try:
        node = get_node()
        tx_daten = node.getrawtransaction(txid, True)
        return jsonify({'status': 'success', 'transaction': tx_daten})
    except Exception as e:
        return jsonify({'status': 'error', 'message': str(e)}), 500

# ==========================================
# ENDPUNKT 4: Guthaben & UTXOs via Electrs
# ==========================================
@app.route('/api/guthaben/<adresse>', methods=['GET'])
def get_guthaben(adresse):
    try:
        script_hash = address_to_electrum_hash(adresse)

        # Balance (confirmed + unconfirmed)
        balance = electrs_query("blockchain.scripthash.get_balance", [script_hash])

        # UTXOs (nur unspent outputs)
        utxos = electrs_query("blockchain.scripthash.listunspent", [script_hash])

        confirmed   = balance["confirmed"]
        unconfirmed = balance["unconfirmed"]

        return jsonify({
            'status':           'success',
            'adresse':          adresse,
            'guthaben_btc':     confirmed / 1e8,
            'unconfirmed_btc':  unconfirmed / 1e8,
            'guthaben_sat':     confirmed,
            'unconfirmed_sat':  unconfirmed,
            'anzahl_utxos':     len(utxos),
            'utxos': [
                {
                    'tx_hash': u['tx_hash'],
                    'tx_pos':  u['tx_pos'],
                    'value':   u['value'],        # Satoshi
                    'height':  u['height']
                }
                for u in utxos
            ]
        })

    except Exception as e:
        return jsonify({'status': 'error', 'message': str(e)}), 500

# ==========================================
# ENDPUNKT 5: Transaktion senden (POST)
# ==========================================
@app.route('/api/sendtx', methods=['POST'])
def send_tx():
    try:
        daten = request.get_json()
        if not daten or 'hex' not in daten:
            return jsonify({'status': 'error', 'message': 'Kein gueltiger Hex-String uebergeben.'}), 400

        raw_tx_hex = daten['hex']
        node = get_node()
        txid = node.sendrawtransaction(raw_tx_hex)

        return jsonify({
            'status':  'success',
            'message': 'Transaktion erfolgreich an das Netzwerk uebermittelt!',
            'txid':    txid
        })
    except Exception as e:
        return jsonify({'status': 'error', 'message': str(e)}), 500

# ==========================================
# Server starten
# ==========================================
if __name__ == '__main__':
    print("🚀 API Server startet...")
    app.run(host='0.0.0.0', port=5001)