<?php
/**
 * controllers/soilImportController.php
 *
 * Handles XLS/XLSX/CSV upload from soil labs.
 *
 * POST /controllers/soilImportController.php
 *   file        — multipart upload
 *   lab         — lab identifier: "csbp" | "generic"
 *   action      — "parse"       → detect lab, return sample list
 *                 "import_one"  → map + return fields for one sample (form pre-fill)
 *                 "import_bulk" → save all (or selected) samples directly to DB
 *   sample_idx  — (import_one) 0-based index
 *   samples     — (import_bulk) JSON array of sample objects with overrides applied by user
 *   client_id   — (import_bulk) client_records.id to link records to
 */

require_once __DIR__ . '/../config/database.php';
require_once __DIR__ . '/../lib/llm.php';  // llama.cpp primary + Ollama fallback (includes config/ai.php)
require_once __DIR__ . '/../lib/auth.php';
require_once __DIR__ . '/../lib/csrf.php';
require_once __DIR__ . '/labParsers/csbp.php';

if (session_status() === PHP_SESSION_NONE) {
    session_start();
}

requireLogin();
header('Content-Type: application/json');

// ─── helpers ─────────────────────────────────────────────────────────────────

function jsonError(string $message, int $code = 400): never
{
    http_response_code($code);
    echo json_encode(['success' => false, 'error' => $message]);
    exit;
}

function jsonOk(array $data): never
{
    echo json_encode(['success' => true, ...$data]);
    exit;
}

// ─── request validation ───────────────────────────────────────────────────────

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    jsonError('Method not allowed', 405);
}

$action = $_POST['action'] ?? 'parse';
if (!in_array($action, ['parse', 'import_one', 'import_bulk'], true)) {
    jsonError('Invalid action');
}

// ─── file handling ────────────────────────────────────────────────────────────

if (empty($_FILES['file']) || $_FILES['file']['error'] !== UPLOAD_ERR_OK) {
    jsonError('No file uploaded or upload error: ' . ($_FILES['file']['error'] ?? 'missing'));
}

$uploadedFile = $_FILES['file'];
$ext          = strtolower(pathinfo($uploadedFile['name'], PATHINFO_EXTENSION));

if (!in_array($ext, ['xls', 'xlsx', 'csv', 'ods'], true)) {
    jsonError('Unsupported file type. Please upload XLS, XLSX, CSV, or ODS.');
}

// ─── PhpSpreadsheet ───────────────────────────────────────────────────────────

foreach ([__DIR__ . '/../vendor/autoload.php', __DIR__ . '/../../vendor/autoload.php'] as $p) {
    if (file_exists($p)) { require_once $p; break; }
}

if (!class_exists('\PhpOffice\PhpSpreadsheet\IOFactory')) {
    jsonError('PhpSpreadsheet not installed. Run: composer install', 500);
}

use PhpOffice\PhpSpreadsheet\IOFactory;

try {
    $spreadsheet = IOFactory::load($uploadedFile['tmp_name']);
} catch (\Exception $e) {
    jsonError('Could not read file: ' . $e->getMessage());
}

$sheet   = $spreadsheet->getActiveSheet();
$rawData = [];
foreach ($sheet->getRowIterator() as $row) {
    $cells = [];
    foreach ($row->getCellIterator() as $cell) {
        $cells[] = trim((string) $cell->getFormattedValue());
    }
    while ($cells && end($cells) === '') {
        array_pop($cells);
    }
    if ($cells) {
        $rawData[] = $cells;
    }
}

if (empty($rawData)) {
    jsonError('The spreadsheet appears to be empty.');
}

// ─── Lab detection ────────────────────────────────────────────────────────────
//
// Client can tell us the lab via POST['lab'], or we auto-detect.

$lab = strtolower(trim($_POST['lab'] ?? 'auto'));

if ($lab === 'auto' || $lab === '') {
    if (csbpDetect($rawData)) {
        $lab = 'csbp';
    } else {
        $lab = 'generic';
    }
}

// ─── Parse into samples ───────────────────────────────────────────────────────

if ($lab === 'csbp') {
    $samples = csbpParse($rawData);
} else {
    $samples = genericParse($rawData);
}

if (empty($samples)) {
    jsonError('No samples found in the file. Check the correct lab is selected.');
}

// ─── action: parse ────────────────────────────────────────────────────────────

if ($action === 'parse') {
    $list = [];
    foreach ($samples as $idx => $s) {
        $list[] = [
            'idx'       => $idx,
            'lab_no'    => $s['lab_no']      ?? 'Sample ' . ($idx + 1),
            'sample_id' => $s['sample_id']   ?? '',   // paddock
            'client'    => $s['client_name'] ?? '',
            'crop'      => $s['crop_type']   ?? '',
        ];
    }
    jsonOk(['samples' => $list, 'count' => count($samples), 'lab' => $lab]);
}

// ─── action: import_one ───────────────────────────────────────────────────────
// Returns mapped field values for a single sample to pre-fill the form.

if ($action === 'import_one') {
    $idx = (int) ($_POST['sample_idx'] ?? 0);
    if ($idx < 0 || $idx >= count($samples)) {
        jsonError('Invalid sample index.');
    }

    $fields = $samples[$idx];

    // If generic lab, try AI mapping on top
    if ($lab === 'generic') {
        $fields = ollamaMap($fields);
    }

    $fields = array_filter($fields, fn($v) => $v !== null && $v !== '');
    jsonOk(['fields' => $fields, 'method' => $lab === 'csbp' ? 'csbp' : 'ai']);
}

// ─── action: import_bulk ─────────────────────────────────────────────────────
// Saves all samples (with user-confirmed paddock IDs) directly to soil_records.

if ($action === 'import_bulk') {
    $clientId       = (int) ($_POST['client_id'] ?? 0);
    $userId         = (int) getCurrentUserId();
    $confirmedJson  = $_POST['samples'] ?? '[]';
    $confirmed      = json_decode($confirmedJson, true);

    if (!is_array($confirmed) || empty($confirmed)) {
        // Fall back to all parsed samples
        $confirmed = $samples;
    }

    if (!$clientId) {
        jsonError('Please select a client before bulk importing.');
    }

    $pdo = getDBConnection();
    $inserted = 0;
    $skipped  = [];

    foreach ($confirmed as $s) {
        // Require at minimum a lab number or sample ID
        if (empty($s['lab_no']) && empty($s['sample_id'])) {
            $skipped[] = 'Row missing lab number and paddock';
            continue;
        }

        // Avoid duplicates: skip if this lab_no already exists for this client
        if (!empty($s['lab_no'])) {
            $dup = $pdo->prepare("
                SELECT id FROM soil_records
                WHERE lab_no = ? AND CAST(client_records_id AS UNSIGNED) = ?
                LIMIT 1
            ");
            $dup->execute([$s['lab_no'], $clientId]);
            if ($dup->fetch()) {
                $skipped[] = ($s['lab_no'] ?? '') . ' (duplicate)';
                continue;
            }
        }

        $rand = (string) (mt_rand(1000, 9999) / 1000); // matches existing rand pattern

        $stmt = $pdo->prepare("
            INSERT INTO soil_records (
                client_records_id, modx_user_id, date, client_name,
                analysis_type, lab_no, batch_no, sample_id, site_id,
                crop_type, soil_type, date_sampled,
                texture, gravel, colour,
                ph_cacl2, ph_h2o, ec, ocarbon, omatter, paramag,
                NO3_N, NH3_N,
                p_mehlick, p_bray2, p_morgan,
                k_morgan, ca_morgan, mg_morgan, na_morgan, s_morgan,
                b_cacl2, mn_dtpa, zn_dtpa, fe_dtpa, cu_dtpa, al, se,
                tec, cec, ca_mehlick3, mg_mehlick3, k_mehlick3, na_mehlick3, al_mehlick3,
                rand, status
            ) VALUES (
                ?, ?, NOW(), ?,
                ?, ?, ?, ?, ?,
                ?, ?, ?,
                ?, ?, ?,
                ?, ?, ?, ?, ?, ?,
                ?, ?,
                ?, ?, ?,
                ?, ?, ?, ?, ?,
                ?, ?, ?, ?, ?, ?, ?,
                ?, ?, ?, ?, ?, ?, ?,
                ?, '0'
            )
        ");

        $n = fn(string $key) => isset($s[$key]) && $s[$key] !== '' ? (float) $s[$key] : null;
        $t = fn(string $key) => $s[$key] ?? null;

        $stmt->execute([
            $clientId, $userId, $t('client_name'),
            $t('analysis_type'), $t('lab_no'), $t('batch_no'), $t('sample_id'), $t('site_id'),
            $t('crop_type'), $t('soil_type'), $t('date_sampled'),
            $t('texture'), $n('gravel'), $t('colour'),
            $n('ph_cacl2'), $n('ph_h2o'), $n('ec'), $n('ocarbon'), $n('omatter'), $n('paramag'),
            $n('NO3_N'), $n('NH3_N'),
            $n('p_mehlick'), $n('p_bray2'), $n('p_morgan'),
            $n('k_morgan'), $n('ca_morgan'), $n('mg_morgan'), $n('na_morgan'), $n('s_morgan'),
            $n('b_cacl2'), $n('mn_dtpa'), $n('zn_dtpa'), $n('fe_dtpa'), $n('cu_dtpa'), $n('al'), $n('se'),
            $n('tec'), $n('cec'), $n('ca_mehlick3'), $n('mg_mehlick3'), $n('k_mehlick3'), $n('na_mehlick3'), $n('al_mehlick3'),
            $rand,
        ]);

        $inserted++;
    }

    jsonOk([
        'inserted' => $inserted,
        'skipped'  => $skipped,
        'message'  => "{$inserted} sample" . ($inserted !== 1 ? 's' : '') . " imported successfully."
                    . (count($skipped) ? ' Skipped: ' . implode(', ', $skipped) : ''),
    ]);
}

// ─── Generic parser (non-CSBP files) ─────────────────────────────────────────

function genericParse(array $rawData): array
{
    // Reuse the original detection + extraction logic for unknown labs
    $fmt = detectGenericFormat($rawData);
    return $fmt['transposed']
        ? extractTransposed($rawData)
        : extractRowBased($rawData, $fmt['headerRow']);
}

function detectGenericFormat(array $rawData): array
{
    $transposedSignals = [
        '1:5', 'total p', 'total k', 'total ca', 'total mg', 'total na',
        'total s', 'total n', 'total b', 'total zn', 'total mn', 'total fe',
        'total cu', 'organic matter', 'organic carbon', 'lab id', 'nitrate ppm',
        'ph 1:5', 'moisture %', 'consultant', 'field name',
    ];
    $rowBasedSignals = [
        'lab_number', 'custno', 'paddock', 'ph_cacl2', 'ph_h2o',
        'dtpa_cu', 'dtpa_zn', 'dtpa_mn', 'dtpa_fe', 'conducty',
        'orgcarbon', 'nitrate', 'nammonium', 'texture', 'gravel',
        'exc_ca', 'exc_mg', 'exc_na', 'exc_k', 'alum_cacl2',
        'boron_hot', 'client name', 'lab number', 'sat_ca', 'sat_mg',
        'sat_k', 'sat_na', 'crop', 'sp%',
    ];

    $transposedScore = 0;
    foreach (array_slice($rawData, 0, 20) as $row) {
        $cell = strtolower($row[0] ?? '');
        foreach ($transposedSignals as $sig) {
            if (str_contains($cell, $sig)) { $transposedScore++; break; }
        }
    }
    if ($transposedScore >= 2) {
        return ['transposed' => true, 'headerRow' => 0];
    }

    $bestRow = 0; $bestScore = 0;
    for ($i = 0; $i < min(10, count($rawData)); $i++) {
        $score = 0;
        foreach ($rawData[$i] as $cell) {
            $cell = strtolower(trim($cell));
            foreach ($rowBasedSignals as $sig) {
                if (str_contains($cell, $sig)) { $score++; break; }
            }
        }
        if ($score > $bestScore) { $bestScore = $score; $bestRow = $i; }
    }
    return ['transposed' => false, 'headerRow' => $bestRow];
}

function extractRowBased(array $rawData, int $headerRow): array
{
    $headers = $rawData[$headerRow];
    $samples = [];
    for ($r = $headerRow + 1; $r < count($rawData); $r++) {
        $row = $rawData[$r]; $sample = [];
        foreach ($headers as $c => $header) {
            if ($header === '') continue;
            $sample[$header] = $row[$c] ?? '';
        }
        if (count(array_filter($sample)) >= 3) $samples[] = $sample;
    }
    return $samples;
}

function extractTransposed(array $rawData): array
{
    $labels = array_column($rawData, 0);
    $maxCols = max(array_map('count', $rawData));
    $samples = [];
    for ($col = 1; $col < $maxCols; $col++) {
        $sample = [];
        foreach ($rawData as $ri => $row) {
            $label = trim($labels[$ri] ?? '');
            $value = trim($row[$col] ?? '');
            if ($label !== '' && $value !== '') $sample[$label] = $value;
        }
        if (count(array_filter($sample)) >= 3) $samples[] = $sample;
    }
    return $samples;
}

// ─── Ollama field mapping (generic lab fallback) ──────────────────────────────

function ollamaMap(array $sampleData): array
{
    $labJson = json_encode($sampleData, JSON_UNESCAPED_UNICODE);

    $prompt = <<<EOT
You are a soil laboratory data mapper. Output ONLY a JSON object — no explanation, no markdown.

Map the LAB DATA to these TARGET FIELDS:
lab_no=Lab reference number
sample_id=Sample/paddock identifier
site_id=Site/block identifier
date_sampled=Date as YYYY-MM-DD
texture=Soil texture
gravel=Gravel % (number)
colour=Soil colour
ocarbon=Organic carbon % (number)
omatter=Organic matter % (number)
ph_cacl2=pH CaCl2 (number)
ph_h2o=pH water (number)
ec=EC dS/m (number)
NO3_N=Nitrate-N mg/kg (number)
NH3_N=Ammonium-N mg/kg (number)
p_morgan=Phosphorus mg/kg (number)
k_morgan=Potassium mg/kg (number)
ca_morgan=Calcium mg/kg (number)
mg_morgan=Magnesium mg/kg (number)
na_morgan=Sodium mg/kg (number)
s_morgan=Sulphur mg/kg (number)
b_cacl2=Boron mg/kg (number)
mn_dtpa=Manganese mg/kg (number)
zn_dtpa=Zinc mg/kg (number)
fe_dtpa=Iron mg/kg (number)
cu_dtpa=Copper mg/kg (number)
al=Aluminium mg/kg (number)
cec=CEC meq/100g (number)

LAB DATA: {$labJson}

Rules: only use values in the data. Strip units. Use null for unmapped. Output JSON only.
EOT;

    try {
        $rawText = llmGenerate($prompt, [
            'temperature' => OLLAMA_TEMPERATURE,
            'num_predict' => 512,
        ]);
    } catch (RuntimeException $e) {
        return $sampleData;  // All backends failed — return unmapped data
    }
    $rawText = trim($rawText);
    $rawText = preg_replace('/^```(?:json)?\s*/i', '', $rawText);
    $rawText = preg_replace('/\s*```$/m', '', $rawText);
    if (preg_match('/\{[\s\S]+\}/', $rawText, $m)) $rawText = $m[0];

    $mapped = json_decode($rawText, true);
    return is_array($mapped) ? $mapped : $sampleData;
}