<?php
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * Finalisasi fondasi Persediaan.
 *
 * Migration bersifat additive. Data transaksi dan ledger lama tidak dihapus
 * agar seluruh perubahan tetap dapat diaudit ketika diterapkan di production.
 */
class Migration_Finalize_professional_inventory extends CI_Migration
{
    public function up()
    {
        $this->upgradeDocuments();
        $this->upgradeMasters();
        $this->upgradeReservations();
        $this->createHistoryTables();
        $this->addPerformanceIndexes();
        $this->backfillCompany();
    }

    private function addColumn($table, $column, $definition)
    {
        // Do not use CI's schema cache during a long migration. A preceding
        // ALTER can otherwise leave table_exists/field_exists stale.
        if ($this->tableExists($table) && !$this->fieldExists($table, $column)) {
            $this->db->query("ALTER TABLE `{$table}` ADD `{$column}` {$definition}");
        }
    }

    private function addIndex($table, $name, array $columns, $unique = false)
    {
        if (!$this->tableExists($table)) return;
        foreach ($columns as $column) if (!$this->fieldExists($table, $column)) return;
        $exists = $this->db->query(
            'SELECT 1 FROM information_schema.statistics WHERE table_schema=DATABASE() AND table_name=? AND index_name=? LIMIT 1',
            array($table, $name)
        )->row();
        if (!$exists) {
            $quoted = '`'.implode('`,`', $columns).'`';
            $this->db->query('ALTER TABLE `'.$table.'` ADD '.($unique ? 'UNIQUE ' : '').'KEY `'.$name.'` ('.$quoted.')');
        }
    }

    private function tableExists($table)
    {
        return (bool) $this->db->query(
            'SELECT 1 FROM information_schema.tables WHERE table_schema=DATABASE() AND table_name=? LIMIT 1',
            array($table)
        )->row();
    }

    private function fieldExists($table, $column)
    {
        return (bool) $this->db->query(
            'SELECT 1 FROM information_schema.columns WHERE table_schema=DATABASE() AND table_name=? AND column_name=? LIMIT 1',
            array($table, $column)
        )->row();
    }

    private function upgradeDocuments()
    {
        $this->addColumn('stock_documents', 'company_id', 'BIGINT UNSIGNED NULL AFTER `id`');
        $this->addColumn('stock_documents', 'source_type', 'VARCHAR(50) NULL AFTER `reason`');
        $this->addColumn('stock_documents', 'source_id', 'BIGINT UNSIGNED NULL AFTER `source_type`');
        $this->addColumn('stock_documents', 'submitted_by', 'INT NULL AFTER `created_by`');
        $this->addColumn('stock_documents', 'submitted_at', 'DATETIME NULL AFTER `submitted_by`');
        $this->addColumn('stock_documents', 'rejected_by', 'INT NULL AFTER `approved_at`');
        $this->addColumn('stock_documents', 'rejected_at', 'DATETIME NULL AFTER `rejected_by`');
        $this->addColumn('stock_documents', 'rejection_reason', 'TEXT NULL AFTER `rejected_at`');
        $this->addColumn('stock_documents', 'reversal_of_id', 'BIGINT UNSIGNED NULL AFTER `rejection_reason`');
        $this->addColumn('stock_documents', 'reversed_by', 'INT NULL AFTER `posted_at`');
        $this->addColumn('stock_documents', 'reversed_at', 'DATETIME NULL AFTER `reversed_by`');
        $this->addColumn('stock_documents', 'updated_by', 'INT NULL AFTER `created_at`');
        $this->addColumn('stock_documents', 'updated_at', 'DATETIME NULL AFTER `updated_by`');
        $this->addColumn('stock_document_lines', 'line_no', 'INT NOT NULL DEFAULT 1 AFTER `stock_document_id`');
        $this->addColumn('stock_document_lines', 'movement_direction', "ENUM('in','out') NULL AFTER `qty`");
        $this->addColumn('stock_document_lines', 'source_line_type', 'VARCHAR(50) NULL AFTER `reason`');
        $this->addColumn('stock_document_lines', 'source_line_id', 'BIGINT UNSIGNED NULL AFTER `source_line_type`');
    }

    private function upgradeMasters()
    {
        $this->addColumn('warehouses', 'code', 'VARCHAR(30) NULL AFTER `company_id`');
        $this->addColumn('warehouses', 'address', 'TEXT NULL AFTER `nama`');
        $this->addColumn('warehouses', 'is_active', 'TINYINT(1) NOT NULL DEFAULT 1 AFTER `address`');
        $this->addColumn('warehouse_bins', 'company_id', 'BIGINT UNSIGNED NULL AFTER `id`');
        $this->addColumn('warehouse_bins', 'updated_at', 'DATETIME NULL AFTER `is_active`');
        $this->addColumn('inventory_batches', 'company_id', 'BIGINT UNSIGNED NULL AFTER `id`');
        $this->addColumn('inventory_batches', 'is_active', 'TINYINT(1) NOT NULL DEFAULT 1 AFTER `supplier_id`');
        $this->addColumn('inventory_batches', 'updated_at', 'DATETIME NULL AFTER `created_at`');
        $this->addColumn('kode_barang', 'company_id', 'BIGINT UNSIGNED NULL AFTER `id`');
        $this->addColumn('kode_barang', 'is_active', 'TINYINT(1) NOT NULL DEFAULT 1');
    }

    private function upgradeReservations()
    {
        $this->addColumn('stock_reservations', 'company_id', 'BIGINT UNSIGNED NULL AFTER `id`');
        $this->addColumn('stock_reservations', 'notes', 'TEXT NULL AFTER `expires_at`');
        $this->addColumn('stock_reservations', 'updated_by', 'INT NULL AFTER `created_by`');
        $this->addColumn('stock_reservations', 'updated_at', 'DATETIME NULL AFTER `created_at`');
        $this->addColumn('stock_reservations', 'completed_at', 'DATETIME NULL AFTER `updated_at`');
        $this->addColumn('inventory_reconciliations', 'company_id', 'BIGINT UNSIGNED NULL AFTER `id`');
        $this->addColumn('inventory_reconciliations', 'stock_log_value', 'DECIMAL(18,2) NULL AFTER `ledger_value`');
        $this->addColumn('inventory_reconciliations', 'barcode_variance_count', 'INT NOT NULL DEFAULT 0 AFTER `difference`');
        $this->addColumn('inventory_reconciliations', 'cache_variance_count', 'INT NOT NULL DEFAULT 0 AFTER `barcode_variance_count`');
    }

    private function createHistoryTables()
    {
        $this->db->query("CREATE TABLE IF NOT EXISTS stock_document_status_history(
            id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
            stock_document_id BIGINT UNSIGNED NOT NULL,
            from_status VARCHAR(30) NULL,
            to_status VARCHAR(30) NOT NULL,
            notes TEXT NULL,
            user_id INT NULL,
            created_at DATETIME NOT NULL,
            KEY idx_stock_document_history(stock_document_id,created_at),
            CONSTRAINT fk_stock_document_history FOREIGN KEY(stock_document_id) REFERENCES stock_documents(id)
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4");
        $this->db->query("CREATE TABLE IF NOT EXISTS stock_reservation_status_history(
            id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
            stock_reservation_id BIGINT UNSIGNED NOT NULL,
            from_status VARCHAR(30) NULL,
            to_status VARCHAR(30) NOT NULL,
            qty DECIMAL(18,4) NOT NULL DEFAULT 0,
            notes TEXT NULL,
            user_id INT NULL,
            created_at DATETIME NOT NULL,
            KEY idx_stock_reservation_history(stock_reservation_id,created_at),
            CONSTRAINT fk_stock_reservation_history FOREIGN KEY(stock_reservation_id) REFERENCES stock_reservations(id)
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4");
    }

    private function addPerformanceIndexes()
    {
        $this->addIndex('stock_documents', 'idx_stock_doc_company_action', array('company_id','status','document_date','id'));
        $this->addIndex('stock_documents', 'idx_stock_doc_source', array('company_id','source_type','source_id'));
        $this->addIndex('stock_documents', 'idx_stock_doc_reversal', array('reversal_of_id'));
        $this->addIndex('stock_document_lines', 'idx_stock_doc_line_item', array('stock_document_id','item_id','id'));
        $this->addIndex('stock_reservations', 'idx_stock_reservation_action', array('company_id','status','expires_at','id'));
        $this->addIndex('warehouse_bins', 'idx_warehouse_bin_active', array('company_id','warehouse_id','is_active','code'));
        $this->addIndex('inventory_batches', 'idx_inventory_batch_active', array('company_id','item_id','is_active','expiry_date'));
        $this->addIndex('item_barcodes', 'idx_item_barcode_lookup', array('item_id','warehouse_id','status','id'));
        $this->addIndex('stock_logs', 'idx_stock_log_item_wh_ref', array('item_id','warehouse_id','ref_type','ref_id'));
        $this->addIndex('transaction_attachments', 'idx_attachment_module_entity', array('module','entity_type','entity_id','id'));
        $this->addIndex('kode_barang', 'idx_item_code_company_active', array('company_id','is_active','kode_barang'));
    }

    private function backfillCompany()
    {
        $fallback = $this->db->select_min('id')->get('companies')->row();
        $companyId = $fallback ? (int) $fallback->id : 1;
        $this->db->query("UPDATE warehouse_bins b JOIN warehouses w ON w.id=b.warehouse_id SET b.company_id=COALESCE(b.company_id,w.company_id,?) WHERE b.company_id IS NULL", array($companyId));
        $this->db->query("UPDATE inventory_batches b JOIN items i ON i.id=b.item_id SET b.company_id=COALESCE(b.company_id,i.company_id,?) WHERE b.company_id IS NULL", array($companyId));
        $this->db->query("UPDATE stock_reservations r JOIN items i ON i.id=r.item_id SET r.company_id=COALESCE(r.company_id,i.company_id,?) WHERE r.company_id IS NULL", array($companyId));
        $this->db->query("UPDATE stock_documents d LEFT JOIN stock_document_lines l ON l.stock_document_id=d.id LEFT JOIN items i ON i.id=l.item_id SET d.company_id=COALESCE(d.company_id,i.company_id,?) WHERE d.company_id IS NULL", array($companyId));
        $this->db->query("UPDATE inventory_reconciliations SET company_id=? WHERE company_id IS NULL", array($companyId));
        $this->db->query("UPDATE kode_barang k LEFT JOIN items i ON i.kode_id=k.id SET k.company_id=COALESCE(k.company_id,i.company_id,?) WHERE k.company_id IS NULL", array($companyId));
        $this->db->query("UPDATE warehouses SET code=CONCAT('GD-',LPAD(id,3,'0')) WHERE code IS NULL OR code='' ");
    }

    public function down()
    {
        throw new RuntimeException('Rollback finalisasi Persediaan wajib menggunakan backup database.');
    }
}