import mysql.connector
import pandas as pd
import io
from flask import send_file, render_template, request

from AppCode.Config import DBConfig


class ITRHandler:

    def __init__(self):
        self.conn = DBConfig.get_db_connection()
        self.cursor = self.conn.cursor(dictionary=True)
        
    # GET ALL ITR RECORDS using stored procedure "GetAllItr"
    def get_all_itr(self):
        self.cursor.callproc("GetAllItr")
        records = []
        for result in self.cursor.stored_results():
            records = result.fetchall()

        return records

    # get itr record by id
    def get_itr_by_id(self, id):
        # Call stored procedure
        self.cursor.callproc('GetITRById', [id])

        # Fetch result
        records = []
        for result in self.cursor.stored_results():
            records = result.fetchall()

        if records:
            print(records[0])
            return records[0]  # return single record
           
        return None


    # INSERT ITR RECORD using procedure "add_itr"
    def add_itr(self, data):

        try:
            columns = [
                'year', 'gross_total_income', 'disallowance_14a', 'disallowance_37',
                'deduction_80ia_business', 'deduction_80ia_misc', 'deduction_80ia_other',
                'deduction_sec37_disallowance', 'deduction_80g',
                'net_taxable_income', 'tax_30_percent', 'tax_book_profit_18_5',
                'tax_payable', 'surcharge', 'edu_cess',
                'total_tax_payable', 'mat_credit_created', 'mat_credit_utilized',
                'interest_234c', 'total_tax', 'advance_tax', 'tds', 'tcs',
                'sat', 'tax_on_assessment', 'refund', 'Remarks','created_at'
            ]
            values = [data.get(col, 0) for col in columns]

            # Call your stored procedure
            self.cursor.callproc("InsertITR", values)
            self.conn.commit()
        except Exception as e:
            self.conn.rollback()
            raise e
        finally:
            self.cursor.close()
            self.conn.close()


    # update itr by id
    def update(self, id, data):
        columns = [
            'year', 'gross_total_income', 'disallowance_14a', 'disallowance_37',
            'deduction_80ia_business', 'deduction_80ia_misc', 'deduction_80ia_other',
            'deduction_sec37_disallowance', 'deduction_80g',
            'net_taxable_income', 'tax_30_percent', 'tax_book_profit_18_5',
            'tax_payable', 'surcharge', 'edu_cess',
            'total_tax_payable', 'mat_credit_created', 'mat_credit_utilized',
            'interest_234c', 'total_tax', 'advance_tax', 'tds', 'tcs',
            'sat', 'tax_on_assessment', 'refund', 'Remarks'
        ]

        values = [id] + [data.get(col, 0) for col in columns]  
        self.cursor.callproc("UpdateITR", values)
        self.conn.commit()


    # DELETE RECORD by ITR id
    def delete_itr_by_id(self, id):
        self.cursor.callproc('DeleteITRById', [id])
        self.conn.commit()


    # # report download by year  
    def itr_report_download(self, selected_year):
        try:
            # Call stored procedure
            self.cursor.callproc("GetITRByYear", [selected_year])

            rows = []
            for result in self.cursor.stored_results():
                rows = result.fetchall()

            if not rows:
                return None
            for row in rows:
                row.pop('id', None)

            # Mapping DB fields → Excel labels (NO underscores)
            field_mapping = {
                "gross_total_income": "Gross Total Income",
                "disallowance_14a": "Add: Disallowance u/s 14A",
                "disallowance_37": "Add: Disallowance u/s 37",
                "deduction_80ia_business": "Less: Deduction u/s 80IA - On Business Income",
                "deduction_80ia_misc": "On Misc Receipts",
                "deduction_80ia_other": "On Other",
                "deduction_sec37_disallowance": "On Sec 37 Disallowance",
                "deduction_80g": "Less: Deduction u/s 80G",
                "net_taxable_income": "Net Taxable Income",
                "tax_30_percent": "Tax @ 30%",
                "tax_book_profit_18_5": "Tax @ 18.5% on Book Profit",
                "tax_payable": "Tax Payable",
                "surcharge": "Surcharge @ %",
                "edu_cess": "Education Cess @ %",
                "total_tax_payable": "Total Tax Payable",
                "mat_credit_created": "Add: MAT Credit Created",
                "mat_credit_utilized": "Less: MAT Credit Utilized",
                "interest_234c": "Add: Interest u/s 234C",
                "total_tax": "Total Tax",
                "advance_tax": "Advance Tax",
                "tds": "TDS",
                "tcs": "TCS",
                "sat": "SAT",
                "tax_on_assessment": "Tax on Regular Assessment",
                "refund": "Refund"
            }

            # Convert to vertical structure
            data = []
            for key, label in field_mapping.items():
                value = rows[0].get(key, 0)
                data.append([label, value])

            df = pd.DataFrame(data, columns=["Particulars", "ITR"])

            # Excel output
            output = io.BytesIO()
            with pd.ExcelWriter(output, engine="xlsxwriter") as writer:
                workbook = writer.book
                worksheet = workbook.add_worksheet("ITR Report")
                writer.sheets["ITR Report"] = worksheet

                # Formats
                title_fmt = workbook.add_format({
                    "bold": True, "align": "center", "valign": "vcenter",
                    "font_size": 14
                })
                header_fmt = workbook.add_format({
                    "bold": True, "border": 1, "align": "center"
                })
                cell_fmt = workbook.add_format({"border": 1})
                num_fmt = workbook.add_format({"border": 1, "num_format": "#,##0.00"})

                # Company name
                worksheet.merge_range("A1:B1", "Laxmi Civil Engineering Services Pvt Ltd", title_fmt)

                ay_start = int(selected_year)
                ay_end = ay_start + 1
                assessment_year = f"AY {ay_start}-{ay_end}"

                # Assessment Year
                worksheet.merge_range(
                    "A2:B2",
                    f"Assessment Year : {assessment_year}",
                    workbook.add_format({"align": "center", "bold": True})
                )

                # Headers
                worksheet.write_row("A4", ["Particulars", "ITR"], header_fmt)

                # Data rows
                row_no = 4
                for _, row in df.iterrows():
                    worksheet.write(row_no, 0, row["Particulars"], cell_fmt)
                    worksheet.write(row_no, 1, row["ITR"], num_fmt)
                    row_no += 1

                # Column widths
                worksheet.set_column("A:A", 45)
                worksheet.set_column("B:B", 20)

            output.seek(0)
            return output

        except mysql.connector.Error as e:
            print("MySQL Error →", e)
            return None

    # CLOSE CONNECTION
    def close(self):
        self.cursor.close()
        self.conn.close()