"""
Homelegance ERP Bridge — FastAPI service
Calls erp_api.* stored functions in the ERP PostgreSQL database.
Listens on 127.0.0.1:8080 (internal only, never exposed to the internet).

Selected columns per endpoint are defined in COLUMNS_* dicts below.
Adjust those dicts to add / remove fields without touching query logic.
"""

from __future__ import annotations

import json
import logging
import os
from contextlib import asynccontextmanager
from typing import Any

import asyncpg
from dotenv import load_dotenv
from fastapi import Depends, FastAPI, Header, HTTPException, Path
from pydantic import BaseModel, Field

# ──────────────────────────────────────────────────────────────────────────────
# Config
# ──────────────────────────────────────────────────────────────────────────────
load_dotenv()

ERP_DATABASE_URL: str = os.environ["ERP_DATABASE_URL"]
ERP_API_KEY: str = os.environ["ERP_API_KEY"]
PORT: int = int(os.getenv("PORT", "8080"))

logging.basicConfig(level=logging.INFO, format="%(levelname)s  %(message)s")
log = logging.getLogger(__name__)

# ──────────────────────────────────────────────────────────────────────────────
# Selected-column configuration
# Each key is the JSON key returned by the ERP stored function.
# Set the value to True to include it in the API response.
# ──────────────────────────────────────────────────────────────────────────────

COLUMNS_CATALOG: set[str] = {
    "Model",
    "Manufacturer",
    "Description",
    "Type",           # product category
    "Department",
    "Color",
    "UOM",
    "Status",
    "StockQTY",
    "EstimatedValue",
}

COLUMNS_CONTACTS: set[str] = {
    "ContactID",
    "Company",
    "ContactName1",
    "Phone1",
    "Email1",
    "Address1",
    "City",
    "State",
    "Country",
    "Sales1",         # primary sales rep
    "AR_CreditHold",
    "Active",
    "Terms",
    "PriceType",
}

COLUMNS_ORDERS_LIST: set[str] = {
    "SOID",
    "OrderType",
    "Status",
    "SubStatus",
    "CustomerName",
    "CustomerCID",
    "POID",
    "Model",
    "Quantity",
    "UnitPrice",
    "TotalPrice",
    "InvoiceNo",
    "InvoiceDate",
    "TrackingNumber",
    "ETD",
    "ShipVia",
    "Carrier",
    "SODate",
    "ScheduleDate",
}

# Columns for the sales_order_get header (flat fields)
COLUMNS_ORDER_HEADER: set[str] = {
    "SOID",
    "POID",
    "OrderType",
    "Status",
    "StatusDesc",
    "CustomerName",
    "CustomerCID",
    "ReceiverName",
    "ReceiverAddress1",
    "ReceiverCity",
    "ReceiverState",
    "ReceiverCountry",
    "ReceiverZipcode",
    "ShipVia",
    "Shipper",
    "ScheduleDate",
    "ArrivalDate",
    "Notes",
    "InternalNote",
    "ModifyTime",
}

# Columns for each item inside the Items[] array
COLUMNS_ORDER_ITEM: set[str] = {
    "LineNo",
    "ItemID",
    "Model",
    "Manufacturer",
    "Description",
    "Quantity",
    "UnitPrice",
    "TotalPrice",
    "Status",
    "StatusDesc",
    "ETD",
    "ItemNote",
    "WarehouseID",
    "InvoiceQuantity",
    "TransactedQuantity",
}

COLUMNS_STOCK: set[str] = {
    "Model",
    "Manufacturer",
    "Description",
    "Quantity",
    "PalletID",
    "WarehouseCID",
    "SubInv",
    "HoldByPalletID",
    "HoldByRef",
    "B_ETA",
    "A_ETA",
    "SalesOrderID",
}

# ──────────────────────────────────────────────────────────────────────────────
# DB Pool (lifespan)
# ──────────────────────────────────────────────────────────────────────────────
DB_POOL: asyncpg.Pool | None = None


@asynccontextmanager
async def lifespan(app: FastAPI):
    global DB_POOL
    log.info("Connecting to ERP database …")
    DB_POOL = await asyncpg.create_pool(
        ERP_DATABASE_URL,
        min_size=2,
        max_size=10,
        command_timeout=30,
        statement_cache_size=0,   # required when using pgBouncer in transaction mode
    )
    log.info("ERP database pool ready.")
    yield
    if DB_POOL:
        await DB_POOL.close()
    log.info("ERP database pool closed.")


app = FastAPI(
    title="Homelegance ERP Bridge",
    version="1.0.0",
    docs_url=None,   # disable Swagger UI in production
    redoc_url=None,
    lifespan=lifespan,
)

# ──────────────────────────────────────────────────────────────────────────────
# Auth dependency
# ──────────────────────────────────────────────────────────────────────────────

def verify_api_key(x_api_key: str = Header(..., alias="X-API-Key")) -> None:
    if x_api_key != ERP_API_KEY:
        raise HTTPException(status_code=401, detail="Invalid API key")


# ──────────────────────────────────────────────────────────────────────────────
# Helpers
# ──────────────────────────────────────────────────────────────────────────────

def filter_keys(obj: dict, allowed: set[str]) -> dict:
    """Return a new dict containing only the allowed keys."""
    return {k: v for k, v in obj.items() if k in allowed}


def filter_list(rows: list[dict], allowed: set[str]) -> list[dict]:
    return [filter_keys(r, allowed) for r in rows]


async def call_list_fn(fn_name: str, conditions: dict, limit: int) -> list[dict]:
    """Call an erp_api list stored function that accepts (jsonb, int) and returns json."""
    assert DB_POOL is not None
    sql = f"SELECT erp_api.{fn_name}($1::jsonb, $2)"
    row = await DB_POOL.fetchrow(sql, json.dumps(conditions), limit)
    if row is None:
        return []
    result = row[0]
    if result is None:
        return []
    data = json.loads(result) if isinstance(result, str) else result
    return data if isinstance(data, list) else []


def pick(obj: dict | None, keys: set[str]) -> dict:
    if not obj:
        return {}
    return {k: obj[k] for k in keys if k in obj}


# ──────────────────────────────────────────────────────────────────────────────
# Request / response models
# ──────────────────────────────────────────────────────────────────────────────

class CatalogRequest(BaseModel):
    model: str | None = Field(None, description="Partial model number (ILIKE search)")
    manufacturer: str | None = Field(None, description="Manufacturer filter")
    description: str | None = Field(None, description="Description keyword")
    category: str | None = Field(None, description="Product category / Type")
    status: str | None = Field(None, description="Item status code (e.g. 'A' for active)")
    limit: int = Field(20, ge=1, le=200)


class ContactsRequest(BaseModel):
    contact_id: str | None = Field(None, description="Exact ContactID")
    company: str | None = Field(None, description="Company name (partial match)")
    name: str | None = Field(None, description="Contact person name")
    limit: int = Field(20, ge=1, le=200)


class OrdersListRequest(BaseModel):
    so_id: str | None = Field(None, description="Sales Order ID (partial match)")
    customer_name: str | None = Field(None, description="Customer name (partial match)")
    customer_cid: str | None = Field(None, description="Customer CID (exact)")
    po_id: str | None = Field(None, description="PO number (partial match)")
    status: str | None = Field(None, description="Order status code")
    limit: int = Field(20, ge=1, le=200)


class StockRequest(BaseModel):
    model: str | None = Field(None, description="Model number (partial match)")
    warehouse_cid: str | None = Field(None, description="Warehouse code")
    limit: int = Field(50, ge=1, le=500)


# ──────────────────────────────────────────────────────────────────────────────
# Endpoints
# ──────────────────────────────────────────────────────────────────────────────

@app.get("/health")
async def health() -> dict:
    """Simple liveness probe — no auth required."""
    return {"status": "ok", "service": "erp-bridge"}


@app.post("/catalog", dependencies=[Depends(verify_api_key)])
async def catalog_search(req: CatalogRequest) -> list[dict[str, Any]]:
    """
    Search the product catalog.
    Calls erp_api.catalog_lists(conditions jsonb, limit int).
    """
    conditions: dict[str, Any] = {}
    if req.model:
        conditions["Model"] = req.model
    if req.manufacturer:
        conditions["Manufacturer"] = req.manufacturer
    if req.description:
        conditions["Description"] = req.description
    if req.category:
        conditions["Type"] = req.category
    if req.status:
        conditions["Status"] = req.status

    rows = await call_list_fn("catalog_lists", conditions, req.limit)
    return filter_list(rows, COLUMNS_CATALOG)


@app.post("/contacts", dependencies=[Depends(verify_api_key)])
async def contacts_search(req: ContactsRequest) -> list[dict[str, Any]]:
    """
    Search customers / contacts.
    Calls erp_api.contact_lists(conditions jsonb, limit int).
    """
    conditions: dict[str, Any] = {}
    if req.contact_id:
        conditions["ContactID"] = req.contact_id
    if req.company:
        conditions["Company"] = req.company
    if req.name:
        conditions["ContactName"] = req.name

    rows = await call_list_fn("contact_lists", conditions, req.limit)
    return filter_list(rows, COLUMNS_CONTACTS)


@app.post("/orders", dependencies=[Depends(verify_api_key)])
async def orders_list(req: OrdersListRequest) -> list[dict[str, Any]]:
    """
    List sales orders (one row per line item).
    Calls erp_api.sales_orders_lists(conditions jsonb, limit int).
    """
    conditions: dict[str, Any] = {}
    if req.so_id:
        conditions["SOID"] = req.so_id
    if req.customer_name:
        conditions["CustomerName"] = req.customer_name
    if req.customer_cid:
        conditions["CustomerCID"] = req.customer_cid
    if req.po_id:
        conditions["POID"] = req.po_id
    if req.status:
        conditions["Status"] = req.status

    rows = await call_list_fn("sales_orders_lists", conditions, req.limit)
    return filter_list(rows, COLUMNS_ORDER_HEADER)


@app.get("/orders/{so_id}", dependencies=[Depends(verify_api_key)])
async def order_get(so_id: str = Path(..., description="Sales Order ID")) -> dict[str, Any]:
    """
    Retrieve a single sales order with nested Items and Notes.
    Calls erp_api.sales_order_get(so_id text).
    """
    assert DB_POOL is not None
    sql = "SELECT erp_api.sales_order_get($1)"
    try:
        row = await DB_POOL.fetchrow(sql, so_id)
    except asyncpg.PostgresError as e:
        raise HTTPException(status_code=404, detail=str(e))

    if row is None or row[0] is None:
        raise HTTPException(status_code=404, detail=f"Sales order not found: {so_id}")

    full: dict = json.loads(row[0]) if isinstance(row[0], str) else row[0]

    # Filter header columns
    result = pick(full, COLUMNS_ORDER_HEADER)

    # Filter Items array
    items_raw: list[dict] = full.get("Items") or []
    result["Items"] = [pick(item, COLUMNS_ORDER_ITEM) for item in items_raw]

    # Include Notes array as-is (already minimal)
    result["Notes"] = full.get("Notes") or []

    return result


@app.post("/stock", dependencies=[Depends(verify_api_key)])
async def stock_search(req: StockRequest) -> list[dict[str, Any]]:
    """
    Search available stock (pallet level).
    Calls erp_api.stock_lists(conditions jsonb, limit int).
    """
    conditions: dict[str, Any] = {}
    if req.model:
        conditions["Model"] = req.model
    if req.warehouse_cid:
        conditions["WarehouseCID"] = req.warehouse_cid

    rows = await call_list_fn("stock_lists", conditions, req.limit)
    return filter_list(rows, COLUMNS_STOCK)


# ──────────────────────────────────────────────────────────────────────────────
# Dev runner (not used in production — uvicorn is started by systemd)
# ──────────────────────────────────────────────────────────────────────────────
if __name__ == "__main__":
    import uvicorn
    uvicorn.run("main:app", host="127.0.0.1", port=PORT, reload=False)