<?php

/**
 * Converted from CBACT01C.CBL
 * Mainframe COBOL batch program to PHP 8 modernization pipeline
 */

// Strict typing for safety
declare(strict_types=1);

/**
 * Parses a zoned decimal field to integer cents (sen)
 * Handles trailing overpunch characters (both EBCDIC and ASCII standard/GnuCOBOL styles)
 */
function parseZoned(string $val): int {
    $val = trim($val);
    if ($val === '') {
        return 0;
    }
    
    $len = strlen($val);
    $lastChar = $val[$len - 1];
    $digits = substr($val, 0, $len - 1);
    
    // Comprehensive map for positive/unsigned and negative zoned decimal trailing overpunches
    static $map = [
        // Positive / Unsigned
        '{' => [0, 1], 'A' => [1, 1], 'B' => [2, 1], 'C' => [3, 1], 'D' => [4, 1],
        'E' => [5, 1], 'F' => [6, 1], 'G' => [7, 1], 'H' => [8, 1], 'I' => [9, 1],
        // Negative (EBCDIC / Standard ASCII)
        '}' => [0, -1], 'J' => [1, -1], 'K' => [2, -1], 'L' => [3, -1], 'M' => [4, -1],
        'N' => [5, -1], 'O' => [6, -1], 'P' => [7, -1], 'Q' => [8, -1], 'R' => [9, -1],
        // Negative (GnuCOBOL / Micro Focus ASCII)
        'p' => [0, -1], 'q' => [1, -1], 'r' => [2, -1], 's' => [3, -1], 't' => [4, -1],
        'u' => [5, -1], 'v' => [6, -1], 'w' => [7, -1], 'x' => [8, -1], 'y' => [9, -1],
    ];
    
    if (isset($map[$lastChar])) {
        [$lastDigit, $sign] = $map[$lastChar];
    } elseif (ctype_digit($lastChar)) {
        $lastDigit = (int)$lastChar;
        $sign = 1;
    } else {
        $lastDigit = 0;
        $sign = 1;
    }
    
    $numStr = $digits . $lastDigit;
    return $sign * (int)$numStr;
}

/**
 * Formats integer cents (sen) to trailing zoned decimal S9(10)V99 (12 chars)
 * Positive values are plain digits, negative values overpunch the last digit to ASCII style (p-y)
 */
function formatZoned(int $sen, int $length = 12): string {
    $absVal = abs($sen);
    $str = str_pad((string)$absVal, $length, '0', STR_PAD_LEFT);
    if ($sen < 0) {
        $lastDigit = (int)$str[$length - 1];
        $lastChar = chr(0x70 + $lastDigit);
        $str = substr($str, 0, $length - 1) . $lastChar;
    }
    return $str;
}

/**
 * Formats integer cents (sen) to COMP-3 packed decimal (7 bytes)
 * One pad nibble 0, 12 digit nibbles, and one sign nibble (0xC / 0xD)
 */
function formatComp3(int $sen, int $numDigits = 12): string {
    $absVal = abs($sen);
    $digitsStr = str_pad((string)$absVal, $numDigits, '0', STR_PAD_LEFT);
    $nibblesStr = '0' . $digitsStr;
    $signNibble = ($sen >= 0) ? 'c' : 'd';
    $nibblesStr .= $signNibble;
    return pack('H*', $nibblesStr);
}

/**
 * Emulates COBDATFT behaviour with CODATECN-TYPE='2' and CODATECN-OUTTYPE='2'
 * Converts YYYY-MM-DD to YYYYMMDD left-justified in 20-char field,
 * truncated to 10-char output field.
 */
function convertDate(string $inpDate): string {
    if (strlen($inpDate) < 10) {
        return str_pad($inpDate, 10, ' ', STR_PAD_RIGHT);
    }
    $yyyy = substr($inpDate, 0, 4);
    $mm = substr($inpDate, 5, 2);
    $dd = substr($inpDate, 8, 2);
    return $yyyy . $mm . $dd . '  ';
}

// Execution main block
function main(): void {
    $acctDataPath = getenv('ACCT_DATA');
    $workDir = getenv('WORK');
    
    if (!$acctDataPath || !$workDir) {
        fwrite(STDERR, "Error: ACCT_DATA or WORK environment variables are not set.\n");
        exit(1);
    }
    
    if (!file_exists($acctDataPath)) {
        fwrite(STDERR, "Error: Input file does not exist at $acctDataPath\n");
        exit(1);
    }
    
    if (!is_dir($workDir)) {
        if (!mkdir($workDir, 0777, true) && !is_dir($workDir)) {
            fwrite(STDERR, "Error: Work directory does not exist and could not be created at $workDir\n");
            exit(1);
        }
    }
    
    $inHandle = fopen($acctDataPath, 'rb');
    if (!$inHandle) {
        fwrite(STDERR, "Error: Could not open input file $acctDataPath\n");
        exit(1);
    }
    
    $outPath = $workDir . '/outfile-gemini.dat';
    $outHandle = fopen($outPath, 'wb');
    if (!$outHandle) {
        fclose($inHandle);
        fwrite(STDERR, "Error: Could not open output file $outPath\n");
        exit(1);
    }
    
    $recordsProcessed = 0;
    $bytesWritten = 0;
    
    // Persistent output record buffer state emulating COBOL memory behavior
    $out_record = [
        'OUT-ACCT-ID' => '',
        'OUT-ACCT-ACTIVE-STATUS' => ' ',
        'OUT-ACCT-CURR-BAL' => 0,
        'OUT-ACCT-CREDIT-LIMIT' => 0,
        'OUT-ACCT-CASH-CREDIT-LIMIT' => 0,
        'OUT-ACCT-OPEN-DATE' => str_repeat(' ', 10),
        'OUT-ACCT-EXPIRAION-DATE' => str_repeat(' ', 10),
        'OUT-ACCT-REISSUE-DATE' => str_repeat(' ', 10),
        'OUT-ACCT-CURR-CYC-CREDIT' => 0,
        'OUT-ACCT-CURR-CYC-DEBIT' => 0,
        'OUT-ACCT-GROUP-ID' => str_repeat(' ', 10),
    ];
    
    while (($line = fgets($inHandle)) !== false) {
        $line = rtrim($line, "\r\n");
        if (strlen($line) === 0) {
            continue;
        }
        
        if (strlen($line) < 300) {
            $line = str_pad($line, 300, ' ', STR_PAD_RIGHT);
        }
        
        // Parse input record (ACCOUNT-RECORD) using standard copybook layout
        $acct_id = trim(substr($line, 0, 11));
        $acct_active_status = substr($line, 11, 1);
        $acct_curr_bal = parseZoned(substr($line, 12, 12));
        $acct_credit_limit = parseZoned(substr($line, 24, 12));
        $acct_cash_credit_limit = parseZoned(substr($line, 36, 12));
        $acct_open_date = substr($line, 48, 10);
        $acct_expiraion_date = substr($line, 58, 10);
        $acct_reissue_date = substr($line, 68, 10);
        $acct_curr_cyc_credit = parseZoned(substr($line, 78, 12));
        $acct_curr_cyc_debit = parseZoned(substr($line, 90, 12));
        $acct_group_id = substr($line, 112, 10);
        
        // 1300-POPUL-ACCT-RECORD
        $out_record['OUT-ACCT-ID'] = $acct_id;
        $out_record['OUT-ACCT-ACTIVE-STATUS'] = $acct_active_status;
        $out_record['OUT-ACCT-CURR-BAL'] = $acct_curr_bal;
        $out_record['OUT-ACCT-CREDIT-LIMIT'] = $acct_credit_limit;
        $out_record['OUT-ACCT-CASH-CREDIT-LIMIT'] = $acct_cash_credit_limit;
        $out_record['OUT-ACCT-OPEN-DATE'] = $acct_open_date;
        $out_record['OUT-ACCT-EXPIRAION-DATE'] = $acct_expiraion_date;
        $out_record['OUT-ACCT-REISSUE-DATE'] = convertDate($acct_reissue_date);
        $out_record['OUT-ACCT-CURR-CYC-CREDIT'] = $acct_curr_cyc_credit;
        
        if ($acct_curr_cyc_debit === 0) {
            $out_record['OUT-ACCT-CURR-CYC-DEBIT'] = 252500;
        } else {
            $out_record['OUT-ACCT-CURR-CYC-DEBIT'] = $acct_curr_cyc_debit;
        }
        
        $out_record['OUT-ACCT-GROUP-ID'] = $acct_group_id;
        
        // 1350-WRITE-ACCT-RECORD
        $formatted_id = str_pad($out_record['OUT-ACCT-ID'], 11, '0', STR_PAD_LEFT);
        $formatted_status = str_pad($out_record['OUT-ACCT-ACTIVE-STATUS'], 1, ' ', STR_PAD_RIGHT);
        $formatted_curr_bal = formatZoned($out_record['OUT-ACCT-CURR-BAL'], 12);
        $formatted_credit_limit = formatZoned($out_record['OUT-ACCT-CREDIT-LIMIT'], 12);
        $formatted_cash_credit_limit = formatZoned($out_record['OUT-ACCT-CASH-CREDIT-LIMIT'], 12);
        $formatted_open_date = str_pad($out_record['OUT-ACCT-OPEN-DATE'], 10, ' ', STR_PAD_RIGHT);
        $formatted_expiraion_date = str_pad($out_record['OUT-ACCT-EXPIRAION-DATE'], 10, ' ', STR_PAD_RIGHT);
        $formatted_reissue_date = str_pad($out_record['OUT-ACCT-REISSUE-DATE'], 10, ' ', STR_PAD_RIGHT);
        $formatted_curr_cyc_credit = formatZoned($out_record['OUT-ACCT-CURR-CYC-CREDIT'], 12);
        $formatted_curr_cyc_debit = formatComp3($out_record['OUT-ACCT-CURR-CYC-DEBIT'], 12);
        $formatted_group_id = str_pad($out_record['OUT-ACCT-GROUP-ID'], 10, ' ', STR_PAD_RIGHT);
        
        $recordBuffer = $formatted_id
            . $formatted_status
            . $formatted_curr_bal
            . $formatted_credit_limit
            . $formatted_cash_credit_limit
            . $formatted_open_date
            . $formatted_expiraion_date
            . $formatted_reissue_date
            . $formatted_curr_cyc_credit
            . $formatted_curr_cyc_debit
            . $formatted_group_id;
            
        fwrite($outHandle, $recordBuffer);
        $recordsProcessed++;
        $bytesWritten += strlen($recordBuffer);
    }
    
    fclose($inHandle);
    fclose($outHandle);
    
    echo "Processed $recordsProcessed records, wrote $bytesWritten bytes.\n";
}

main();