import json

from sql import Literal, Null
from sql.functions import CurrentTimestamp

from trytond.model import ModelSQL, ModelView, fields
from trytond.pool import Pool


class FreightBookingShipmentReport(ModelSQL, ModelView):
    "Freight Booking Shipment Report"
    __name__ = 'freight.booking.shipment.report'

    automation_document = fields.Many2One(
        'automation.document', "Automation Document")
    bl_number = fields.Function(fields.Char("BL Number"), 'get_bl_number')
    shipment = fields.Function(fields.Many2One(
        'stock.shipment.in', "Shipment"), 'get_shipment')
    status = fields.Function(fields.Selection([
        ('found', "Found"),
        ('error', "Error"),
    ], "Status"), 'get_status')

    @classmethod
    def __setup__(cls):
        super().__setup__()
        cls._order = [
            ('id', 'DESC'),
        ]

    @classmethod
    def table_query(cls):
        AutomationDocument = Pool().get('automation.document')
        document = AutomationDocument.__table__()

        return document.select(
            Literal(None).as_('create_uid'),
            CurrentTimestamp().as_('create_date'),
            Literal(None).as_('write_uid'),
            Literal(None).as_('write_date'),
            document.id.as_('id'),
            document.id.as_('automation_document'),
            where=(
                (document.type == 'weight_report')
                & (document.metadata_json != Null)))

    @classmethod
    def _extract_bl_number(cls, metadata_json):
        if not metadata_json:
            return None
        try:
            metadata = json.loads(str(metadata_json))
        except (TypeError, ValueError):
            return None

        def find_value(value):
            if isinstance(value, dict):
                for key in (
                        'bl_no', 'bl_number', 'bl', 'BL_Number',
                        'BL number', 'B/L No'):
                    bl_number = value.get(key)
                    if bl_number:
                        return str(bl_number).strip()
                for item in value.values():
                    bl_number = find_value(item)
                    if bl_number:
                        return bl_number
            elif isinstance(value, list):
                for item in value:
                    bl_number = find_value(item)
                    if bl_number:
                        return bl_number
            return None

        return find_value(metadata)

    @classmethod
    def _get_report_data(cls, reports):
        ShipmentIn = Pool().get('stock.shipment.in')
        bl_numbers = {}

        for report in reports:
            document = report.automation_document
            bl_number = cls._extract_bl_number(
                document.metadata_json if document else None)
            bl_numbers[report.id] = bl_number

        shipments_by_bl = {}
        for bl_number in {b for b in bl_numbers.values() if b}:
            shipments = ShipmentIn.search([
                ('bl_number', '=', bl_number),
            ], limit=1)
            if not shipments:
                shipments = ShipmentIn.search([
                    ('bl_number', 'ilike', bl_number),
                ], limit=1)
            shipments_by_bl[bl_number] = shipments[0] if shipments else None

        return bl_numbers, shipments_by_bl

    @classmethod
    def get_bl_number(cls, reports, name):
        bl_numbers, _ = cls._get_report_data(reports)
        return bl_numbers

    @classmethod
    def get_shipment(cls, reports, name):
        bl_numbers, shipments_by_bl = cls._get_report_data(reports)
        return {
            report.id: (
                shipments_by_bl[bl_numbers[report.id]].id
                if bl_numbers[report.id]
                and shipments_by_bl.get(bl_numbers[report.id])
                else None)
            for report in reports
        }

    @classmethod
    def get_status(cls, reports, name):
        bl_numbers, shipments_by_bl = cls._get_report_data(reports)
        return {
            report.id: (
                'found'
                if bl_numbers[report.id]
                and shipments_by_bl.get(bl_numbers[report.id])
                else 'error')
            for report in reports
        }