from typing import List, Optional
from fastapi import APIRouter, HTTPException, Query
from loguru import logger

from leggend.api.models.common import APIResponse
from leggend.api.models.accounts import AccountDetails, AccountBalance, Transaction, TransactionSummary
from leggend.services.gocardless_service import GoCardlessService
from leggend.services.database_service import DatabaseService

router = APIRouter()
gocardless_service = GoCardlessService()
database_service = DatabaseService()


@router.get("/accounts", response_model=APIResponse)
async def get_all_accounts() -> APIResponse:
    """Get all connected accounts"""
    try:
        requisitions_data = await gocardless_service.get_requisitions()
        
        all_accounts = set()
        for req in requisitions_data.get("results", []):
            all_accounts.update(req.get("accounts", []))
        
        accounts = []
        for account_id in all_accounts:
            try:
                account_details = await gocardless_service.get_account_details(account_id)
                balances_data = await gocardless_service.get_account_balances(account_id)
                
                # Process balances
                balances = []
                for balance in balances_data.get("balances", []):
                    balance_amount = balance["balanceAmount"]
                    balances.append(AccountBalance(
                        amount=float(balance_amount["amount"]),
                        currency=balance_amount["currency"],
                        balance_type=balance["balanceType"],
                        last_change_date=balance.get("lastChangeDateTime")
                    ))
                
                accounts.append(AccountDetails(
                    id=account_details["id"],
                    institution_id=account_details["institution_id"],
                    status=account_details["status"],
                    iban=account_details.get("iban"),
                    name=account_details.get("name"),
                    currency=account_details.get("currency"),
                    created=account_details["created"],
                    last_accessed=account_details.get("last_accessed"),
                    balances=balances
                ))
                
            except Exception as e:
                logger.error(f"Failed to get details for account {account_id}: {e}")
                continue
        
        return APIResponse(
            success=True,
            data=accounts,
            message=f"Retrieved {len(accounts)} accounts"
        )
        
    except Exception as e:
        logger.error(f"Failed to get accounts: {e}")
        raise HTTPException(status_code=500, detail=f"Failed to get accounts: {str(e)}")


@router.get("/accounts/{account_id}", response_model=APIResponse)
async def get_account_details(account_id: str) -> APIResponse:
    """Get details for a specific account"""
    try:
        account_details = await gocardless_service.get_account_details(account_id)
        balances_data = await gocardless_service.get_account_balances(account_id)
        
        # Process balances
        balances = []
        for balance in balances_data.get("balances", []):
            balance_amount = balance["balanceAmount"]
            balances.append(AccountBalance(
                amount=float(balance_amount["amount"]),
                currency=balance_amount["currency"],
                balance_type=balance["balanceType"],
                last_change_date=balance.get("lastChangeDateTime")
            ))
        
        account = AccountDetails(
            id=account_details["id"],
            institution_id=account_details["institution_id"],
            status=account_details["status"],
            iban=account_details.get("iban"),
            name=account_details.get("name"),
            currency=account_details.get("currency"),
            created=account_details["created"],
            last_accessed=account_details.get("last_accessed"),
            balances=balances
        )
        
        return APIResponse(
            success=True,
            data=account,
            message=f"Account details retrieved for {account_id}"
        )
        
    except Exception as e:
        logger.error(f"Failed to get account details for {account_id}: {e}")
        raise HTTPException(status_code=404, detail=f"Account not found: {str(e)}")


@router.get("/accounts/{account_id}/balances", response_model=APIResponse)
async def get_account_balances(account_id: str) -> APIResponse:
    """Get balances for a specific account"""
    try:
        balances_data = await gocardless_service.get_account_balances(account_id)
        
        balances = []
        for balance in balances_data.get("balances", []):
            balance_amount = balance["balanceAmount"]
            balances.append(AccountBalance(
                amount=float(balance_amount["amount"]),
                currency=balance_amount["currency"],
                balance_type=balance["balanceType"],
                last_change_date=balance.get("lastChangeDateTime")
            ))
        
        return APIResponse(
            success=True,
            data=balances,
            message=f"Retrieved {len(balances)} balances for account {account_id}"
        )
        
    except Exception as e:
        logger.error(f"Failed to get balances for account {account_id}: {e}")
        raise HTTPException(status_code=404, detail=f"Failed to get balances: {str(e)}")


@router.get("/accounts/{account_id}/transactions", response_model=APIResponse)
async def get_account_transactions(
    account_id: str,
    limit: Optional[int] = Query(default=100, le=500),
    offset: Optional[int] = Query(default=0, ge=0),
    summary_only: bool = Query(default=False, description="Return transaction summaries only")
) -> APIResponse:
    """Get transactions for a specific account"""
    try:
        account_details = await gocardless_service.get_account_details(account_id)
        transactions_data = await gocardless_service.get_account_transactions(account_id)
        
        # Process transactions
        processed_transactions = database_service.process_transactions(
            account_id, account_details, transactions_data
        )
        
        # Apply pagination
        total_transactions = len(processed_transactions)
        paginated_transactions = processed_transactions[offset:offset + limit]
        
        if summary_only:
            # Return simplified transaction summaries
            summaries = [
                TransactionSummary(
                    internal_transaction_id=txn["internalTransactionId"],
                    date=txn["transactionDate"],
                    description=txn["description"],
                    amount=txn["transactionValue"],
                    currency=txn["transactionCurrency"],
                    status=txn["transactionStatus"],
                    account_id=txn["accountId"]
                )
                for txn in paginated_transactions
            ]
            data = summaries
        else:
            # Return full transaction details
            transactions = [
                Transaction(
                    internal_transaction_id=txn["internalTransactionId"],
                    institution_id=txn["institutionId"],
                    iban=txn["iban"],
                    account_id=txn["accountId"],
                    transaction_date=txn["transactionDate"],
                    description=txn["description"],
                    transaction_value=txn["transactionValue"],
                    transaction_currency=txn["transactionCurrency"],
                    transaction_status=txn["transactionStatus"],
                    raw_transaction=txn["rawTransaction"]
                )
                for txn in paginated_transactions
            ]
            data = transactions
        
        return APIResponse(
            success=True,
            data=data,
            message=f"Retrieved {len(data)} transactions (showing {offset + 1}-{offset + len(data)} of {total_transactions})"
        )
        
    except Exception as e:
        logger.error(f"Failed to get transactions for account {account_id}: {e}")
        raise HTTPException(status_code=404, detail=f"Failed to get transactions: {str(e)}")