<?php
/**
 * controllers/labParsers/csbp.php
 *
 * Dedicated parser for CSBP Soil Analysis Report files.
 *
 * Format (both .xls and .xlsx):
 *   Row 1-2  empty
 *   Row 3    "SOIL CONTROL SOIL ANALYSIS REPORT"
 *   Row 4    "CSBP LIMITED ABN: ..."
 *   Row 5    Units row  (mg/kg, pH, dS/m …)
 *   Row 6    Column headers (47 columns — see MAP below)
 *   Row 7+   One sample per row
 *
 * Provides:
 *   csbpDetect(array $rawData): bool
 *   csbpParse(array $rawData): array   — returns array of mapped sample arrays
 */

// ─── CSBP column → soil_records field map ────────────────────────────────────
//
// Keys are CSBP header names (case-insensitive match).
// Values are soil_records column names.

const CSBP_COLUMN_MAP = [
    // Identity / metadata
    'CLIENT NAME'  => 'client_name',
    'PADDOCK'      => 'sample_id',       // paddock = sample identifier
    'CROP'         => 'crop_type',
    'SERIAL_NO'    => 'batch_no',
    'LAB_NUMBER'   => 'lab_no',

    // Physical
    'TEXTURE'      => 'texture',
    'GRAVEL'       => 'gravel',
    'COLOUR'       => 'colour',
    'MOISTURE'     => null,              // not stored in soil_records

    // Chemical
    'CONDUCTY'     => 'ec',
    'PH_CACL2'     => 'ph_cacl2',
    'PH_H2O'       => 'ph_h2o',

    // Nitrogen
    'NITRATEN'     => 'NO3_N',
    'AMMONIUM'     => 'NH3_N',
    'TOTALN'       => null,

    // Phosphorus
    'PHOS'         => 'p_morgan',
    'PHOS_OLS'     => 'p_bray2',        // Olsen P ≈ closest mapped field
    'PHOS_RETEN'   => null,
    'TOTALP'       => null,
    'PBI'          => null,

    // Potassium
    'POTASSIUM'    => 'k_morgan',

    // Other macros
    'SULPHUR'      => 's_morgan',
    'ORGCARBON'    => 'ocarbon',
    'CHLORIDE'     => null,
    'FIZZ'         => null,

    // DTPA micronutrients
    'DTPA_CU'      => 'cu_dtpa',
    'DTPA_ZN'      => 'zn_dtpa',
    'DTPA_MN'      => 'mn_dtpa',
    'DTPA_FE'      => 'fe_dtpa',

    // EDTA micronutrients (map to same fields — DTPA takes priority if both present)
    'EDTA_CU'      => 'cu_dtpa',
    'EDTA_ZN'      => 'zn_dtpa',
    'EDTA_MN'      => 'mn_dtpa',
    'EDTA_FE'      => 'fe_dtpa',

    // Other micros
    'IRON'         => 'fe_dtpa',        // generic iron reading
    'BORON_HOT'    => 'b_cacl2',
    'ALUM_CACL2'   => 'al',

    // Exchangeable cations (base saturation)
    'EXC_CA'       => 'ca_morgan',
    'EXC_MG'       => 'mg_morgan',
    'EXC_NA'       => 'na_morgan',
    'EXC_K'        => null,             // separate from k_morgan (extractable)
    'EXC_AL'       => 'al_mehlick3',

    // Base saturation %
    'SAT_Ca'       => 'ca_mehlick3',
    'SAT_Mg'       => 'mg_mehlick3',
    'SAT_K'        => 'k_mehlick3',
    'SAT_Na'       => 'na_mehlick3',
    'SAT_COND'     => 'cec',            // conductance of saturation extract ≈ CEC proxy
    'SP%'          => null,
];

/**
 * Check if a 2-D raw data array looks like a CSBP file.
 * Looks for "CSBP" or "SOIL CONTROL SOIL ANALYSIS" in the first 6 rows.
 */
function csbpDetect(array $rawData): bool
{
    foreach (array_slice($rawData, 0, 6) as $row) {
        foreach ($row as $cell) {
            $cell = strtoupper(trim((string) $cell));
            if (str_contains($cell, 'CSBP') || str_contains($cell, 'SOIL CONTROL SOIL ANALYSIS')) {
                return true;
            }
        }
    }
    return false;
}

/**
 * Find the header row index inside $rawData.
 * The CSBP header row contains "LAB_NUMBER" and "PADDOCK".
 */
function csbpFindHeaderRow(array $rawData): int
{
    foreach ($rawData as $idx => $row) {
        $cells = array_map(fn($c) => strtoupper(trim((string) $c)), $row);
        if (in_array('LAB_NUMBER', $cells, true) && in_array('PADDOCK', $cells, true)) {
            return $idx;
        }
    }
    return 5; // fallback: row index 5 (row 6 in 1-based)
}

/**
 * Parse a CSBP raw data array into an array of mapped sample arrays.
 * Each sample is keyed by soil_records column names.
 *
 * @param  array $rawData   2-D array from PhpSpreadsheet
 * @return array            [ ['lab_no'=>..., 'ph_cacl2'=>..., ...], ... ]
 */
function csbpParse(array $rawData): array
{
    $headerRow = csbpFindHeaderRow($rawData);
    $headers   = array_map(fn($c) => trim((string) $c), $rawData[$headerRow]);

    // Build index: column position → soil_records field name (or null to skip)
    $colIndex = [];
    foreach ($headers as $col => $header) {
        if ($header === '') continue;
        // Case-insensitive lookup in the map
        $upperHeader = strtoupper($header);
        foreach (CSBP_COLUMN_MAP as $csbpCol => $dbField) {
            if (strtoupper($csbpCol) === $upperHeader) {
                $colIndex[$col] = $dbField; // null means skip
                break;
            }
        }
    }

    $samples = [];
    for ($r = $headerRow + 1; $r < count($rawData); $r++) {
        $row    = $rawData[$r];
        $sample = [];
        $hasData = false;

        foreach ($colIndex as $col => $dbField) {
            $raw = trim((string) ($row[$col] ?? ''));
            if ($dbField === null) continue; // unmapped column
            if ($raw === '') continue;

            // Don't overwrite a DTPA value with an EDTA value
            if (isset($sample[$dbField]) && $sample[$dbField] !== '') continue;

            $sample[$dbField] = $raw;
            $hasData = true;
        }

        // Skip completely empty rows
        if (!$hasData) continue;

        // Mark the lab source
        $sample['analysis_type'] = 'CSBP';

        $samples[] = $sample;
    }

    return $samples;
}