from __future__ import annotations

from datetime import date, datetime
from typing import Any, Iterable


class DataNormalizer:
    def __init__(self, dbconnection):
        self.dbconnection = dbconnection
        self._akahu_account_cache = self._build_akahu_account_cache()

    def read_raw_transactions(self, source: str | None = None, limit: int | None = None) -> list[dict[str, Any]]:
        sql = "SELECT id, data, source FROM rawtransactions WHERE processed = FALSE"
        params: list[Any] = []
        if source:
            sql += " AND source = %s"
            params.append(source)
        sql += " ORDER BY received_at ASC"
        if limit is not None:
            sql += " LIMIT %s"
            params.append(limit)

        with self.dbconnection.cursor() as cursor:
            cursor.execute(sql, params)
            rows = cursor.fetchall()

        return [{"id": row[0], "data": row[1], "source": row[2]} for row in rows]

    def read_raw_snapshots(self, source: str | None = None, limit: int | None = None) -> list[dict[str, Any]]:
        sql = "SELECT id, data, source FROM rawsnapshots WHERE processed = FALSE"
        params: list[Any] = []
        if source:
            sql += " AND source = %s"
            params.append(source)
        sql += " ORDER BY received_at ASC"
        if limit is not None:
            sql += " LIMIT %s"
            params.append(limit)

        with self.dbconnection.cursor() as cursor:
            cursor.execute(sql, params)
            rows = cursor.fetchall()

        return [{"id": row[0], "data": row[1], "source": row[2]} for row in rows]

    def normalize_transactions(self, records: Iterable[dict[str, Any]]) -> None:
        for record in records:
            normalized = self._normalize_transaction(record.get("data"), record.get("source"))
            if not normalized:
                continue
            self._write_transaction(normalized)
            self._mark_processed("rawtransactions", record["id"])

        self.dbconnection.commit()

    def normalize_snapshots(self, records: Iterable[dict[str, Any]]) -> None:
        for record in records:
            normalized = self._normalize_snapshot(record.get("data"), record.get("source"))
            if not normalized:
                continue
            self._write_snapshot(normalized)
            self._mark_processed("rawsnapshots", record["id"])

        self.dbconnection.commit()

    def _normalize_transaction(self, data: Any, source: str | None) -> dict[str, Any] | None:
        if not isinstance(data, dict):
            return None

        if source == "emoney":
            return self._normalize_emoney_transaction(data)
        if source == "akahu":
            return self._normalize_akahu_transaction(data)

        return None

    def _normalize_snapshot(self, data: Any, source: str | None) -> dict[str, Any] | None:
        if not isinstance(data, dict):
            return None

        if source == "emoney":
            return self._normalize_emoney_snapshot(data)
        if source == "akahu":
            return self._normalize_akahu_snapshot(data)

        return None

    def _normalize_emoney_transaction(self, data: dict[str, Any]) -> dict[str, Any] | None:
        required = {"date", "description", "amount"}
        if not required.issubset(data):
            return None

        parsed_date = self._parse_date(data.get("date"))
        if not parsed_date:
            return None

        return {
            "datetime": parsed_date,
            "description": data.get("description"),
            "amount": float(data.get("amount")),
            "account_name": "Emoney",
            "account_num": "emoney",
            "org_name": "Emoney",
            "vendor_name": "Finance Now",
        }

    def _normalize_emoney_snapshot(self, data: dict[str, Any]) -> dict[str, Any] | None:
        if "balance" not in data:
            return None

        parsed_date = self._parse_date(data.get("date")) or date.today()
        return {
            "datetime": parsed_date,
            "balance": float(data.get("balance")),
            "account_name": "Emoney",
            "account_num": "emoney",
            "org_name": "Emoney",
        }

    def _normalize_akahu_transaction(self, data: dict[str, Any]) -> dict[str, Any] | None:
        if "amount" not in data or "description" not in data:
            return None

        parsed_date = self._parse_date(data.get("date") or data.get("created_at"))
        if not parsed_date:
            return None

        account_id = self._string_or_none(data.get("_account") or data.get("account_id") or data.get("account"))
        account_meta = self._akahu_account_cache.get(account_id or "", {})
        account_num = account_meta.get("account_num") or account_id
        account_name = account_meta.get("account_name") or self._string_or_none(data.get("account_name") or data.get("name"))
        org_name = account_meta.get("org_name") or "unknown"

        merchant = data.get("merchant")
        if isinstance(merchant, dict):
            vendor_name = self._string_or_none(merchant.get("name"))
        else:
            vendor_name = self._string_or_none(merchant)
        if not vendor_name:
            vendor_name = self._string_or_none(data.get("payee"))
        if not vendor_name:
            vendor_name = self._string_or_none(data.get("description"))

        description = self._format_akahu_description(data)

        return {
            "datetime": parsed_date,
            "description": description,
            "amount": float(data.get("amount")),
            "account_name": account_name,
            "account_num": account_num,
            "org_name": org_name,
            "vendor_name": vendor_name,
        }

    def _normalize_akahu_snapshot(self, data: dict[str, Any]) -> dict[str, Any] | None:
        if "balance" not in data and "current_balance" not in data:
            return None

        parsed_date = self._parse_date(data.get("date") or data.get("updated_at")) or date.today()
        balance_value = self._parse_balance_value(data.get("balance") or data.get("current_balance"))
        if balance_value is None:
            return None

        account_num = self._string_or_none(data.get("formatted_account") or data.get("_id") or data.get("account_id"))
        connection = data.get("connection") if isinstance(data.get("connection"), dict) else {}
        org_name = self._string_or_none(connection.get("name")) or "unknown"
        return {
            "datetime": parsed_date,
            "balance": balance_value,
            "account_name": self._string_or_none(data.get("name") or data.get("account_name")),
            "account_num": account_num,
            "org_name": org_name,
        }

    def _build_akahu_account_cache(self) -> dict[str, dict[str, str]]:
        cache: dict[str, dict[str, str]] = {}
        with self.dbconnection.cursor() as cursor:
            cursor.execute(
                "SELECT data FROM rawsnapshots WHERE source = %s",
                ("akahu",)
            )
            rows = cursor.fetchall()

        for (data,) in rows:
            if not isinstance(data, dict):
                continue
            account_id = self._string_or_none(data.get("_id") or data.get("id"))
            if not account_id:
                continue
            account_num = self._string_or_none(data.get("formatted_account") or data.get("_id") or data.get("account_id"))
            account_name = self._string_or_none(data.get("name") or data.get("account_name"))
            connection = data.get("connection") if isinstance(data.get("connection"), dict) else {}
            org_name = self._string_or_none(connection.get("name")) or "unknown"
            cache[account_id] = {
                "account_num": account_num or account_id,
                "account_name": account_name or "unknown",
                "org_name": org_name,
            }

        return cache

    def _format_akahu_description(self, data: dict[str, Any]) -> str:
        description = self._string_or_none(data.get("description")) or "unknown"
        meta = data.get("meta") if isinstance(data.get("meta"), dict) else {}

        other_account = self._string_or_none(meta.get("other_account"))
        reference = self._string_or_none(meta.get("reference"))
        particulars = self._string_or_none(meta.get("particulars"))
        code = self._string_or_none(meta.get("code"))

        if "INTERNET XFR" in description:
            target = other_account or reference or particulars or code
            if target:
                description = description.replace("INTERNET XFR", f"-> {target}")

        meta_bits: list[str] = []
        if reference:
            meta_bits.append(f"ref={reference}")
        if particulars:
            meta_bits.append(f"particulars={particulars}")
        if code:
            meta_bits.append(f"code={code}")
        if other_account:
            meta_bits.append(f"other={other_account}")

        if meta_bits:
            description = f"{description} | " + " | ".join(meta_bits)

        return description

    def _write_transaction(self, normalized: dict[str, Any]) -> None:
        org_id = self._get_or_create_org(normalized.get("org_name"))
        account_id = self._get_or_create_account(
            normalized.get("account_num"),
            normalized.get("account_name"),
            org_id,
        )
        vendor_id = None
        vendor_name = normalized.get("vendor_name")
        if vendor_name:
            vendor_id = self._get_or_create_vendor(vendor_name, org_id)

        with self.dbconnection.cursor() as cursor:
            cursor.execute(
                """
                INSERT INTO transactions (datetime, description, amount, accountid, orgid, vendorid)
                VALUES (%s, %s, %s, %s, %s, %s)
                """,
                (
                    normalized.get("datetime"),
                    normalized.get("description"),
                    normalized.get("amount"),
                    account_id,
                    org_id,
                    vendor_id,
                ),
            )

    def _write_snapshot(self, normalized: dict[str, Any]) -> None:
        org_id = self._get_or_create_org(normalized.get("org_name"))
        account_id = self._get_or_create_account(
            normalized.get("account_num"),
            normalized.get("account_name"),
            org_id,
        )

        with self.dbconnection.cursor() as cursor:
            cursor.execute(
                """
                INSERT INTO snapshots (datetime, accountid, balance, orgid)
                VALUES (%s, %s, %s, %s)
                """,
                (
                    normalized.get("datetime"),
                    account_id,
                    normalized.get("balance"),
                    org_id,
                ),
            )

    def _mark_processed(self, table: str, record_id: int) -> None:
        with self.dbconnection.cursor() as cursor:
            cursor.execute(
                f"UPDATE {table} SET processed = TRUE WHERE id = %s",
                (record_id,),
            )

    def _get_or_create_org(self, org_name: str | None) -> int:
        org_name = org_name or "unknown"
        with self.dbconnection.cursor() as cursor:
            cursor.execute("SELECT id FROM organizations WHERE orgname = %s", (org_name,))
            row = cursor.fetchone()
            if row:
                return row[0]

            cursor.execute(
                "INSERT INTO organizations (orgname) VALUES (%s) RETURNING id",
                (org_name,),
            )
            return cursor.fetchone()[0]

    def _get_or_create_account(self, account_num: str | None, account_name: str | None, org_id: int) -> int:
        account_name = account_name or "unknown"
        account_num = account_num or f"{org_id}:{account_name}"
        with self.dbconnection.cursor() as cursor:
            cursor.execute("SELECT id FROM accounts WHERE accountnum = %s", (account_num,))
            row = cursor.fetchone()
            if row:
                return row[0]

            cursor.execute(
                """
                INSERT INTO accounts (accountnum, accountname, orgid)
                VALUES (%s, %s, %s)
                RETURNING id
                """,
                (account_num, account_name, org_id),
            )
            return cursor.fetchone()[0]

    def _get_or_create_vendor(self, vendor_name: str, org_id: int) -> int:
        if vendor_name == "Finance Now":
            with self.dbconnection.cursor() as cursor:
                cursor.execute(
                    "SELECT id FROM vendors WHERE vendorname = %s",
                    (vendor_name,),
                )
                row = cursor.fetchone()
                if row:
                    return row[0]
        with self.dbconnection.cursor() as cursor:
            cursor.execute(
                "SELECT id FROM vendors WHERE vendorname = %s AND orgid = %s",
                (vendor_name, org_id),
            )
            row = cursor.fetchone()
            if row:
                return row[0]

            cursor.execute(
                "INSERT INTO vendors (vendorname, orgid) VALUES (%s, %s) RETURNING id",
                (vendor_name, org_id),
            )
            return cursor.fetchone()[0]

    @staticmethod
    def _parse_date(value: Any) -> date | None:
        if isinstance(value, date) and not isinstance(value, datetime):
            return value
        if isinstance(value, datetime):
            return value.date()
        if isinstance(value, str):
            for fmt in (
                "%Y-%m-%d",
                "%d-%m-%Y",
                "%Y-%m-%dT%H:%M:%S%z",
                "%Y-%m-%dT%H:%M:%SZ",
                "%Y-%m-%dT%H:%M:%S.%fZ",
            ):
                try:
                    return datetime.strptime(value, fmt).date()
                except ValueError:
                    continue
        return None

    @staticmethod
    def _string_or_none(value: Any) -> str | None:
        if value is None:
            return None
        return str(value)

    @staticmethod
    def _parse_balance_value(value: Any) -> float | None:
        if value is None:
            return None
        if isinstance(value, (int, float)):
            return float(value)
        if isinstance(value, str):
            try:
                return float(value)
            except ValueError:
                return None
        if isinstance(value, dict):
            for key in ("amount", "value", "balance"):
                if key in value:
                    return DataNormalizer._parse_balance_value(value.get(key))
        return None