import json
from datetime import datetime
from typing import Optional

from lnbits.db import Database
from lnbits.helpers import urlsafe_short_hash

from .models import (
    Account,
    AccountType,
    CastleSettings,
    CreateAccount,
    CreateEntryLine,
    CreateJournalEntry,
    EntryLine,
    JournalEntry,
    StoredUserWalletSettings,
    UserBalance,
    UserCastleSettings,
    UserWalletSettings,
)

db = Database("ext_castle")


# ===== ACCOUNT OPERATIONS =====


async def create_account(data: CreateAccount) -> Account:
    account_id = urlsafe_short_hash()
    account = Account(
        id=account_id,
        name=data.name,
        account_type=data.account_type,
        description=data.description,
        user_id=data.user_id,
        created_at=datetime.now(),
    )
    await db.insert("accounts", account)
    return account


async def get_account(account_id: str) -> Optional[Account]:
    return await db.fetchone(
        "SELECT * FROM accounts WHERE id = :id",
        {"id": account_id},
        Account,
    )


async def get_account_by_name(name: str) -> Optional[Account]:
    return await db.fetchone(
        "SELECT * FROM accounts WHERE name = :name",
        {"name": name},
        Account,
    )


async def get_all_accounts() -> list[Account]:
    return await db.fetchall(
        "SELECT * FROM accounts ORDER BY account_type, name",
        model=Account,
    )


async def get_accounts_by_type(account_type: AccountType) -> list[Account]:
    return await db.fetchall(
        "SELECT * FROM accounts WHERE account_type = :type ORDER BY name",
        {"type": account_type.value},
        Account,
    )


async def get_or_create_user_account(
    user_id: str, account_type: AccountType, base_name: str
) -> Account:
    """Get or create a user-specific account (e.g., 'Accounts Payable - User123')"""
    account_name = f"{base_name} - {user_id[:8]}"

    account = await db.fetchone(
        """
        SELECT * FROM accounts
        WHERE user_id = :user_id AND account_type = :type AND name = :name
        """,
        {"user_id": user_id, "type": account_type.value, "name": account_name},
        Account,
    )

    if not account:
        account = await create_account(
            CreateAccount(
                name=account_name,
                account_type=account_type,
                description=f"User-specific {account_type.value} account",
                user_id=user_id,
            )
        )

    return account


# ===== JOURNAL ENTRY OPERATIONS =====


async def create_journal_entry(
    data: CreateJournalEntry, created_by: str
) -> JournalEntry:
    entry_id = urlsafe_short_hash()

    # Validate that debits equal credits
    total_debits = sum(line.debit for line in data.lines)
    total_credits = sum(line.credit for line in data.lines)

    if total_debits != total_credits:
        raise ValueError(
            f"Journal entry must balance: debits={total_debits}, credits={total_credits}"
        )

    entry_date = data.entry_date or datetime.now()

    journal_entry = JournalEntry(
        id=entry_id,
        description=data.description,
        entry_date=entry_date,
        created_by=created_by,
        created_at=datetime.now(),
        reference=data.reference,
        lines=[],
    )

    # Insert journal entry without the lines field (lines are stored in entry_lines table)
    await db.execute(
        """
        INSERT INTO journal_entries (id, description, entry_date, created_by, created_at, reference)
        VALUES (:id, :description, :entry_date, :created_by, :created_at, :reference)
        """,
        {
            "id": journal_entry.id,
            "description": journal_entry.description,
            "entry_date": journal_entry.entry_date,
            "created_by": journal_entry.created_by,
            "created_at": journal_entry.created_at,
            "reference": journal_entry.reference,
        },
    )

    # Create entry lines
    lines = []
    for line_data in data.lines:
        line_id = urlsafe_short_hash()
        line = EntryLine(
            id=line_id,
            journal_entry_id=entry_id,
            account_id=line_data.account_id,
            debit=line_data.debit,
            credit=line_data.credit,
            description=line_data.description,
            metadata=line_data.metadata,
        )
        # Insert with metadata as JSON string
        await db.execute(
            """
            INSERT INTO entry_lines (id, journal_entry_id, account_id, debit, credit, description, metadata)
            VALUES (:id, :journal_entry_id, :account_id, :debit, :credit, :description, :metadata)
            """,
            {
                "id": line.id,
                "journal_entry_id": line.journal_entry_id,
                "account_id": line.account_id,
                "debit": line.debit,
                "credit": line.credit,
                "description": line.description,
                "metadata": json.dumps(line.metadata),
            },
        )
        lines.append(line)

    journal_entry.lines = lines
    return journal_entry


async def get_journal_entry(entry_id: str) -> Optional[JournalEntry]:
    entry = await db.fetchone(
        "SELECT * FROM journal_entries WHERE id = :id",
        {"id": entry_id},
        JournalEntry,
    )

    if entry:
        entry.lines = await get_entry_lines(entry_id)

    return entry


async def get_entry_lines(journal_entry_id: str) -> list[EntryLine]:
    rows = await db.fetchall(
        "SELECT * FROM entry_lines WHERE journal_entry_id = :id",
        {"id": journal_entry_id},
    )

    lines = []
    for row in rows:
        # Parse metadata from JSON string
        metadata = json.loads(row.metadata) if row.metadata else {}
        line = EntryLine(
            id=row.id,
            journal_entry_id=row.journal_entry_id,
            account_id=row.account_id,
            debit=row.debit,
            credit=row.credit,
            description=row.description,
            metadata=metadata,
        )
        lines.append(line)

    return lines


async def get_all_journal_entries(limit: int = 100) -> list[JournalEntry]:
    entries = await db.fetchall(
        """
        SELECT * FROM journal_entries
        ORDER BY entry_date DESC, created_at DESC
        LIMIT :limit
        """,
        {"limit": limit},
        JournalEntry,
    )

    for entry in entries:
        entry.lines = await get_entry_lines(entry.id)

    return entries


async def get_journal_entries_by_user(
    user_id: str, limit: int = 100
) -> list[JournalEntry]:
    """Get journal entries that affect the user's accounts"""
    # Get all user-specific accounts
    user_accounts = await db.fetchall(
        "SELECT id FROM accounts WHERE user_id = :user_id",
        {"user_id": user_id},
    )

    if not user_accounts:
        return []

    account_ids = [acc["id"] for acc in user_accounts]

    # Get all journal entries that have lines affecting these accounts
    # Build the IN clause with named parameters
    placeholders = ','.join([f":account_{i}" for i in range(len(account_ids))])
    params = {f"account_{i}": acc_id for i, acc_id in enumerate(account_ids)}
    params["limit"] = limit

    entries_data = await db.fetchall(
        f"""
        SELECT DISTINCT je.*
        FROM journal_entries je
        JOIN entry_lines el ON je.id = el.journal_entry_id
        WHERE el.account_id IN ({placeholders})
        ORDER BY je.entry_date DESC, je.created_at DESC
        LIMIT :limit
        """,
        params,
    )

    entries = []
    for entry_data in entries_data:
        entry = JournalEntry(
            id=entry_data["id"],
            description=entry_data["description"],
            entry_date=entry_data["entry_date"],
            created_by=entry_data["created_by"],
            created_at=entry_data["created_at"],
            reference=entry_data["reference"],
            lines=[],
        )
        entry.lines = await get_entry_lines(entry.id)
        entries.append(entry)

    return entries


# ===== BALANCE AND REPORTING =====


async def get_account_balance(account_id: str) -> int:
    """Calculate account balance (debits - credits for assets/expenses, credits - debits for liabilities/equity/revenue)"""
    result = await db.fetchone(
        """
        SELECT
            COALESCE(SUM(debit), 0) as total_debit,
            COALESCE(SUM(credit), 0) as total_credit
        FROM entry_lines
        WHERE account_id = :id
        """,
        {"id": account_id},
    )

    if not result:
        return 0

    account = await get_account(account_id)
    if not account:
        return 0

    total_debit = result["total_debit"]
    total_credit = result["total_credit"]

    # Normal balance for each account type:
    # Assets and Expenses: Debit balance (debit - credit)
    # Liabilities, Equity, and Revenue: Credit balance (credit - debit)
    if account.account_type in [AccountType.ASSET, AccountType.EXPENSE]:
        return total_debit - total_credit
    else:
        return total_credit - total_debit


async def get_user_balance(user_id: str) -> UserBalance:
    """Get user's balance with the Castle (positive = castle owes user, negative = user owes castle)"""
    # Get all user-specific accounts
    user_accounts = await db.fetchall(
        "SELECT * FROM accounts WHERE user_id = :user_id",
        {"user_id": user_id},
        Account,
    )

    total_balance = 0
    fiat_balances = {}  # Track fiat balances by currency

    for account in user_accounts:
        balance = await get_account_balance(account.id)

        # Get all entry lines for this account to calculate fiat balances
        entry_lines = await db.fetchall(
            "SELECT * FROM entry_lines WHERE account_id = :account_id",
            {"account_id": account.id},
        )

        for line in entry_lines:
            # Parse metadata to get fiat amounts
            metadata = json.loads(line["metadata"]) if line.get("metadata") else {}
            fiat_currency = metadata.get("fiat_currency")
            fiat_amount = metadata.get("fiat_amount")

            if fiat_currency and fiat_amount:
                # Initialize currency if not exists
                if fiat_currency not in fiat_balances:
                    fiat_balances[fiat_currency] = 0.0

                # Calculate fiat balance based on account type
                if account.account_type == AccountType.LIABILITY:
                    # Liability: credit increases (castle owes more), debit decreases
                    if line["credit"] > 0:
                        fiat_balances[fiat_currency] += fiat_amount
                    elif line["debit"] > 0:
                        fiat_balances[fiat_currency] -= fiat_amount
                elif account.account_type == AccountType.ASSET:
                    # Asset (receivable): debit increases (user owes more), credit decreases
                    if line["debit"] > 0:
                        fiat_balances[fiat_currency] -= fiat_amount
                    elif line["credit"] > 0:
                        fiat_balances[fiat_currency] += fiat_amount

        # Calculate satoshi balance
        # If it's a liability account (castle owes user), it's positive
        # If it's an asset account (user owes castle), it's negative
        if account.account_type == AccountType.LIABILITY:
            total_balance += balance
        elif account.account_type == AccountType.ASSET:
            total_balance -= balance
        # Equity contributions are tracked but don't affect what castle owes

    return UserBalance(
        user_id=user_id,
        balance=total_balance,
        accounts=user_accounts,
        fiat_balances=fiat_balances,
    )


async def get_all_user_balances() -> list[UserBalance]:
    """Get balances for all users (used by castle to see who they owe)"""
    # Get all user-specific accounts
    all_accounts = await db.fetchall(
        "SELECT * FROM accounts WHERE user_id IS NOT NULL",
        {},
        Account,
    )

    # Group by user_id
    users_dict = {}
    for account in all_accounts:
        if account.user_id not in users_dict:
            users_dict[account.user_id] = []
        users_dict[account.user_id].append(account)

    # Calculate balance for each user
    user_balances = []
    for user_id, accounts in users_dict.items():
        total_balance = 0
        fiat_balances = {}

        for account in accounts:
            balance = await get_account_balance(account.id)

            # Get all entry lines for this account to calculate fiat balances
            entry_lines = await db.fetchall(
                "SELECT * FROM entry_lines WHERE account_id = :account_id",
                {"account_id": account.id},
            )

            for line in entry_lines:
                # Parse metadata to get fiat amounts
                metadata = json.loads(line["metadata"]) if line.get("metadata") else {}
                fiat_currency = metadata.get("fiat_currency")
                fiat_amount = metadata.get("fiat_amount")

                if fiat_currency and fiat_amount:
                    # Initialize currency if not exists
                    if fiat_currency not in fiat_balances:
                        fiat_balances[fiat_currency] = 0.0

                    # Calculate fiat balance based on account type
                    if account.account_type == AccountType.LIABILITY:
                        # Liability: credit increases (castle owes more), debit decreases
                        if line["credit"] > 0:
                            fiat_balances[fiat_currency] += fiat_amount
                        elif line["debit"] > 0:
                            fiat_balances[fiat_currency] -= fiat_amount
                    elif account.account_type == AccountType.ASSET:
                        # Asset (receivable): debit increases (user owes more), credit decreases
                        if line["debit"] > 0:
                            fiat_balances[fiat_currency] -= fiat_amount
                        elif line["credit"] > 0:
                            fiat_balances[fiat_currency] += fiat_amount

            # Calculate satoshi balance
            if account.account_type == AccountType.LIABILITY:
                total_balance += balance
            elif account.account_type == AccountType.ASSET:
                total_balance -= balance

        if total_balance != 0 or fiat_balances:  # Include users with non-zero balance or fiat balances
            user_balances.append(
                UserBalance(
                    user_id=user_id,
                    balance=total_balance,
                    accounts=accounts,
                    fiat_balances=fiat_balances,
                )
            )

    return user_balances


async def get_account_transactions(
    account_id: str, limit: int = 100
) -> list[tuple[JournalEntry, EntryLine]]:
    """Get all transactions affecting a specific account"""
    rows = await db.fetchall(
        """
        SELECT * FROM entry_lines
        WHERE account_id = :id
        ORDER BY id DESC
        LIMIT :limit
        """,
        {"id": account_id, "limit": limit},
    )

    transactions = []
    for row in rows:
        # Parse metadata from JSON string
        metadata = json.loads(row.metadata) if row.metadata else {}
        line = EntryLine(
            id=row.id,
            journal_entry_id=row.journal_entry_id,
            account_id=row.account_id,
            debit=row.debit,
            credit=row.credit,
            description=row.description,
            metadata=metadata,
        )
        entry = await get_journal_entry(line.journal_entry_id)
        if entry:
            transactions.append((entry, line))

    return transactions


# ===== SETTINGS =====


async def create_castle_settings(
    user_id: str, data: CastleSettings
) -> CastleSettings:
    settings = UserCastleSettings(**data.dict(), id=user_id)
    await db.insert("extension_settings", settings)
    return settings


async def get_castle_settings(user_id: str) -> Optional[CastleSettings]:
    return await db.fetchone(
        """
        SELECT * FROM extension_settings
        WHERE id = :user_id
        """,
        {"user_id": user_id},
        CastleSettings,
    )


async def update_castle_settings(
    user_id: str, data: CastleSettings
) -> CastleSettings:
    settings = UserCastleSettings(**data.dict(), id=user_id)
    await db.update("extension_settings", settings)
    return settings


# ===== USER WALLET SETTINGS =====


async def create_user_wallet_settings(
    user_id: str, data: UserWalletSettings
) -> UserWalletSettings:
    settings = StoredUserWalletSettings(**data.dict(), id=user_id)
    await db.insert("user_wallet_settings", settings)
    return settings


async def get_user_wallet_settings(user_id: str) -> Optional[UserWalletSettings]:
    return await db.fetchone(
        """
        SELECT * FROM user_wallet_settings
        WHERE id = :user_id
        """,
        {"user_id": user_id},
        UserWalletSettings,
    )


async def update_user_wallet_settings(
    user_id: str, data: UserWalletSettings
) -> UserWalletSettings:
    settings = StoredUserWalletSettings(**data.dict(), id=user_id)
    await db.update("user_wallet_settings", settings)
    return settings


async def get_all_user_wallet_settings() -> list[StoredUserWalletSettings]:
    """Get all user wallet settings"""
    return await db.fetchall(
        "SELECT * FROM user_wallet_settings ORDER BY id",
        {},
        StoredUserWalletSettings,
    )