<?php
/**
 * DeclarationTVA Class
 * French CA-3 VAT Declaration Module for Dolibarr
 * MVP Version - Phase 1
 */

class DeclarationTVA
{
    /**
     * @var DoliDB Database handler
     */
    public $db;

    /**
     * @var int Entity ID
     */
    public $entity;

    /**
     * @var string Error message
     */
    public $error;

    /**
     * @var int Declaration ID
     */
    public $rowid;

    /**
     * @var int Period ID
     */
    public $period_id;

    /**
     * @var string Declaration number
     */
    public $declaration_number;

    /**
     * @var string Declaration name
     */
    public $declaration_name;

    /**
     * @var string Start date
     */
    public $start_date;

    /**
     * @var string End date
     */
    public $end_date;

    /**
     * @var string Status
     */
    public $status;

    /**
     * Constructor
     *
     * @param DoliDB $db Database handler
     * @param int $entity Entity ID
     */
    public function __construct($db, $entity = 1)
    {
        $this->db = $db;
        $this->entity = $entity;
    }

    /**
     * Fetch declaration by ID
     *
     * @param int $id Declaration ID
     * @return int 1 if found, 0 if not found, -1 if error
     */
    public function fetch($id)
    {
        $sql = "SELECT * FROM " . MAIN_DB_PREFIX . "declarationtva_declarations 
                WHERE rowid = " . (int)$id . " AND entity = " . $this->entity;
        
        $result = $this->db->query($sql);
        if ($result) {
            $obj = $this->db->fetch_object($result);
            if ($obj) {
                $this->rowid = $obj->rowid;
                $this->period_id = $obj->period_id;
                $this->declaration_number = $obj->declaration_number;
                $this->declaration_name = $obj->declaration_name;
                $this->start_date = $obj->start_date;
                $this->end_date = $obj->end_date;
                $this->status = $obj->status;
                $this->created_date = $obj->created_date;
                return 1;
            }
        }
        return 0;
    }

    /**
     * Create a new declaration for a period
     *
     * @param int $period_id Period ID
     * @return int Declaration ID or -1 if error
     */
    public function createDeclaration($period_id)
    {
        global $user;

        $this->db->begin();

        // Get period information
        $period = $this->getPeriod($period_id);
        if (!$period) {
            $this->error = "Period not found";
            $this->db->rollback();
            return -1;
        }

        // Generate declaration number
        $declaration_number = $this->generateDeclarationNumber($period);

        // Create declaration record
        $sql = "INSERT INTO " . MAIN_DB_PREFIX . "declarationtva_declarations 
                (entity, period_id, declaration_number, status, created_date) 
                VALUES (" . $this->entity . ", " . $period_id . ", '" . $declaration_number . "', 'draft', NOW())";

        $result = $this->db->query($sql);
        if (!$result) {
            $this->error = "Error creating declaration: " . $this->db->lasterror();
            $this->db->rollback();
            return -1;
        }

        $declaration_id = $this->db->last_insert_id(MAIN_DB_PREFIX . "declarationtva_declarations");

        // Calculate CA-3 amounts
        $this->calculateCA3Amounts($declaration_id, $period);

        $this->db->commit();
        return $declaration_id;
    }

    /**
     * Create a new declaration with specific dates
     *
     * @param string $start_date Start date (YYYY-MM-DD)
     * @param string $end_date End date (YYYY-MM-DD)
     * @param string $declaration_name Declaration name
     * @return int Declaration ID or -1 if error
     */
    public function createDeclarationWithDates($start_date, $end_date, $declaration_name = '')
    {
        global $user;

        $this->db->begin();

        // Generate declaration number
        $declaration_number = $this->generateDeclarationNumberFromDates($start_date, $end_date);

        // Create declaration record
        $sql = "INSERT INTO " . MAIN_DB_PREFIX . "declarationtva_declarations 
                (entity, period_id, declaration_number, declaration_name, start_date, end_date, status, created_date) 
                VALUES (" . $this->entity . ", 0, '" . $declaration_number . "', '" . $this->db->escape($declaration_name) . "', '" . $start_date . "', '" . $end_date . "', 'draft', NOW())";

        $result = $this->db->query($sql);
        if (!$result) {
            $this->error = "Error creating declaration: " . $this->db->lasterror();
            $this->db->rollback();
            return -1;
        }

        $declaration_id = $this->db->last_insert_id(MAIN_DB_PREFIX . "declarationtva_declarations");

        // Calculate CA-3 amounts
        $period = array('start_date' => $start_date, 'end_date' => $end_date);
        $this->calculateCA3Amounts($declaration_id, $period);

        $this->db->commit();
        return $declaration_id;
    }

    /**
     * Calculate CA-3 amounts for a declaration
     *
     * @param int $declaration_id Declaration ID
     * @param array $period Period information
     * @return bool Success
     */
    public function calculateCA3Amounts($declaration_id, $period)
    {
        error_log("DeclarationTVA: Starting calculation for declaration $declaration_id");
        error_log("DeclarationTVA: Period: " . $period['start_date'] . " to " . $period['end_date']);
        
        // Get account mappings
        $mappings = $this->getAccountMappings();
        error_log("DeclarationTVA: Found " . count($mappings) . " account mappings");

        $total_vat_collected = 0;
        $total_vat_deductible = 0;

        // Process each CA-3 line
        foreach ($mappings as $mapping) {
            error_log("DeclarationTVA: Processing mapping: " . $mapping['ca3_line'] . " -> " . $mapping['account_code']);
            $amounts = $this->getAccountAmounts($mapping['account_code'], $period['start_date'], $period['end_date']);
            
            // Create CA-3 line record
            $this->createCA3Line($declaration_id, $mapping['ca3_line'], $mapping['account_label'], $amounts);

            // Update totals
            if (in_array($mapping['ca3_line'], ['A1', 'A2', 'B1', 'B2', 'B3', 'B4', '17'])) {
                $total_vat_collected += $amounts['vat_amount'];
            } elseif (in_array($mapping['ca3_line'], ['20', '21'])) {
                $total_vat_deductible += $amounts['vat_amount'];
            }
        }

        error_log("DeclarationTVA: Totals - Collected: $total_vat_collected, Deductible: $total_vat_deductible");

        // Calculate net amounts
        $net_vat_due = $total_vat_collected - $total_vat_deductible;
        $vat_credit = $net_vat_due < 0 ? abs($net_vat_due) : 0;
        $net_vat_due = $net_vat_due > 0 ? $net_vat_due : 0;

        // Update declaration totals
        $this->updateDeclarationTotals($declaration_id, $total_vat_collected, $total_vat_deductible, $net_vat_due, $vat_credit);

        return true;
    }

    /**
     * Get account amounts for a period
     *
     * @param string $account_code Account code
     * @param string $start_date Start date
     * @param string $end_date End date
     * @return array Amounts (base_amount, vat_amount, total_amount)
     */
    public function getAccountAmounts($account_code, $start_date, $end_date)
    {
        // Query Dolibarr accounting entries
        $sql = "SELECT SUM(debit) as total_debit, SUM(credit) as total_credit 
                FROM " . MAIN_DB_PREFIX . "accounting_bookkeeping 
                WHERE account_number = '" . $this->db->escape($account_code) . "' 
                AND doc_date >= '" . $this->db->escape($start_date) . "' 
                AND doc_date <= '" . $this->db->escape($end_date) . "'";

        // Debug: Log the query
        error_log("DeclarationTVA: Querying account $account_code from $start_date to $end_date");
        error_log("DeclarationTVA: SQL: $sql");

        $result = $this->db->query($sql);
        if ($result && $this->db->num_rows($result) > 0) {
            $obj = $this->db->fetch_object($result);
            $total_amount = $obj->total_debit - $obj->total_credit;
            
            error_log("DeclarationTVA: Found amounts for $account_code: debit=$obj->total_debit, credit=$obj->total_credit, net=$total_amount");
            
            return array(
                'base_amount' => $total_amount,
                'vat_amount' => $total_amount,
                'total_amount' => $total_amount
            );
        }

        error_log("DeclarationTVA: No data found for account $account_code");
        return array('base_amount' => 0, 'vat_amount' => 0, 'total_amount' => 0);
    }

    /**
     * Create CA-3 line record
     *
     * @param int $declaration_id Declaration ID
     * @param string $ca3_line CA-3 line code
     * @param string $line_label Line label
     * @param array $amounts Amounts array
     * @return bool Success
     */
    public function createCA3Line($declaration_id, $ca3_line, $line_label, $amounts)
    {
        $sql = "INSERT INTO " . MAIN_DB_PREFIX . "declarationtva_ca3_lines 
                (declaration_id, ca3_line, line_label, base_amount, vat_amount, total_amount, created_date) 
                VALUES (" . $declaration_id . ", '" . $this->db->escape($ca3_line) . "', 
                '" . $this->db->escape($line_label) . "', " . $amounts['base_amount'] . ", 
                " . $amounts['vat_amount'] . ", " . $amounts['total_amount'] . ", NOW())";

        $result = $this->db->query($sql);
        return $result !== false;
    }

    /**
     * Update declaration totals
     *
     * @param int $declaration_id Declaration ID
     * @param float $total_vat_collected Total VAT collected
     * @param float $total_vat_deductible Total VAT deductible
     * @param float $net_vat_due Net VAT due
     * @param float $vat_credit VAT credit
     * @return bool Success
     */
    public function updateDeclarationTotals($declaration_id, $total_vat_collected, $total_vat_deductible, $net_vat_due, $vat_credit)
    {
        $sql = "UPDATE " . MAIN_DB_PREFIX . "declarationtva_declarations 
                SET total_vat_collected = " . $total_vat_collected . ", 
                    total_vat_deductible = " . $total_vat_deductible . ", 
                    net_vat_due = " . $net_vat_due . ", 
                    vat_credit = " . $vat_credit . " 
                WHERE rowid = " . $declaration_id;

        $result = $this->db->query($sql);
        return $result !== false;
    }

    /**
     * Get account mappings
     *
     * @return array Account mappings
     */
    public function getAccountMappings()
    {
        $sql = "SELECT ca3_line, account_code, account_label, vat_rate 
                FROM " . MAIN_DB_PREFIX . "declarationtva_account_mappings 
                WHERE entity = " . $this->entity . " AND is_active = 1 
                ORDER BY ca3_line";

        $result = $this->db->query($sql);
        $mappings = array();

        if ($result) {
            while ($obj = $this->db->fetch_object($result)) {
                $mappings[] = array(
                    'ca3_line' => $obj->ca3_line,
                    'account_code' => $obj->account_code,
                    'account_label' => $obj->account_label,
                    'vat_rate' => $obj->vat_rate
                );
            }
        }

        return $mappings;
    }

    /**
     * Get period information
     *
     * @param int $period_id Period ID
     * @return array|false Period information or false if not found
     */
    public function getPeriod($period_id)
    {
        $sql = "SELECT * FROM " . MAIN_DB_PREFIX . "declarationtva_periods 
                WHERE rowid = " . $period_id . " AND entity = " . $this->entity;

        $result = $this->db->query($sql);
        if ($result && $this->db->num_rows($result) > 0) {
            return $this->db->fetch_array($result);
        }

        return false;
    }

    /**
     * Generate declaration number
     *
     * @param array $period Period information
     * @return string Declaration number
     */
    public function generateDeclarationNumber($period)
    {
        $year = date('Y', strtotime($period['start_date']));
        $start_month = date('m', strtotime($period['start_date']));
        $end_month = date('m', strtotime($period['end_date']));
        
        if ($start_month == $end_month) {
            $month_part = $start_month;
        } else {
            $month_part = $start_month . '-' . $end_month;
        }
        
        return 'CA3-' . $year . '-' . $month_part . '-' . date('YmdHis');
    }

    /**
     * Generate declaration number from dates
     *
     * @param string $start_date Start date
     * @param string $end_date End date
     * @return string Declaration number
     */
    public function generateDeclarationNumberFromDates($start_date, $end_date)
    {
        $year = date('Y', strtotime($start_date));
        $start_month = date('m', strtotime($start_date));
        $end_month = date('m', strtotime($end_date));
        
        if ($start_month == $end_month) {
            $month_part = $start_month;
        } else {
            $month_part = $start_month . '-' . $end_month;
        }
        
        return 'CA3-' . $year . '-' . $month_part . '-' . date('YmdHis');
    }

    /**
     * Get declaration information
     *
     * @param int $declaration_id Declaration ID
     * @return array|false Declaration information or false if not found
     */
    public function getDeclaration($declaration_id)
    {
        $sql = "SELECT d.*, p.period_name, p.start_date, p.end_date 
                FROM " . MAIN_DB_PREFIX . "declarationtva_declarations d 
                LEFT JOIN " . MAIN_DB_PREFIX . "declarationtva_periods p ON d.period_id = p.rowid 
                WHERE d.rowid = " . $declaration_id . " AND d.entity = " . $this->entity;

        $result = $this->db->query($sql);
        if ($result && $this->db->num_rows($result) > 0) {
            return $this->db->fetch_array($result);
        }

        return false;
    }

    /**
     * Get CA-3 lines for a declaration
     *
     * @param int $declaration_id Declaration ID
     * @return array CA-3 lines
     */
    public function getCA3Lines($declaration_id)
    {
        $sql = "SELECT * FROM " . MAIN_DB_PREFIX . "declarationtva_ca3_lines 
                WHERE declaration_id = " . $declaration_id . " 
                ORDER BY ca3_line";

        $result = $this->db->query($sql);
        $lines = array();

        if ($result) {
            while ($obj = $this->db->fetch_object($result)) {
                $lines[] = array(
                    'ca3_line' => $obj->ca3_line,
                    'line_label' => $obj->line_label,
                    'base_amount' => $obj->base_amount,
                    'vat_amount' => $obj->vat_amount,
                    'total_amount' => $obj->total_amount
                );
            }
        }

        return $lines;
    }

    /**
     * Validate declaration
     *
     * @param int $declaration_id Declaration ID
     * @return bool Success
     */
    public function validateDeclaration($declaration_id)
    {
        $sql = "UPDATE " . MAIN_DB_PREFIX . "declarationtva_declarations 
                SET status = 'validated' 
                WHERE rowid = " . $declaration_id . " AND entity = " . $this->entity;

        $result = $this->db->query($sql);
        return $result !== false;
    }

    /**
     * Submit declaration
     *
     * @param int $declaration_id Declaration ID
     * @return bool Success
     */
    public function submitDeclaration($declaration_id)
    {
        $sql = "UPDATE " . MAIN_DB_PREFIX . "declarationtva_declarations 
                SET status = 'submitted', submission_date = NOW() 
                WHERE rowid = " . $declaration_id . " AND entity = " . $this->entity;

        $result = $this->db->query($sql);
        return $result !== false;
    }

    /**
     * Delete a declaration
     *
     * @param int $declaration_id Declaration ID
     * @return bool Success
     */
    public function deleteDeclaration($declaration_id)
    {
        $this->db->begin();

        // Check if declaration exists and is in draft status
        $sql = "SELECT status FROM " . MAIN_DB_PREFIX . "declarationtva_declarations 
                WHERE rowid = " . (int)$declaration_id . " AND entity = " . $this->entity;
        
        $result = $this->db->query($sql);
        if ($result) {
            $obj = $this->db->fetch_object($result);
            if ($obj && $obj->status == 'draft') {
                // Delete CA-3 lines first
                $sql_lines = "DELETE FROM " . MAIN_DB_PREFIX . "declarationtva_ca3_lines 
                              WHERE declaration_id = " . (int)$declaration_id;
                $this->db->query($sql_lines);

                // Delete declaration
                $sql_declaration = "DELETE FROM " . MAIN_DB_PREFIX . "declarationtva_declarations 
                                   WHERE rowid = " . (int)$declaration_id . " AND entity = " . $this->entity;
                
                $result = $this->db->query($sql_declaration);
                if ($result) {
                    $this->db->commit();
                    return true;
                }
            }
        }

        $this->db->rollback();
        return false;
    }


    /**
     * Recalculate CA-3 amounts for a declaration
     *
     * @param int $declaration_id Declaration ID
     * @return bool Success
     */
    public function recalculateCA3Amounts($declaration_id)
    {
        // Get declaration info directly from database
        $sql = "SELECT start_date, end_date FROM " . MAIN_DB_PREFIX . "declarationtva_declarations 
                WHERE rowid = " . $declaration_id . " AND entity = " . $this->entity;
        
        $result = $this->db->query($sql);
        if (!$result || $this->db->num_rows($result) == 0) {
            return false;
        }
        
        $obj = $this->db->fetch_object($result);
        
        // Clear existing CA-3 lines
        $sql = "DELETE FROM " . MAIN_DB_PREFIX . "declarationtva_ca3_lines 
                WHERE declaration_id = " . $declaration_id;
        $this->db->query($sql);
        
        // Recalculate using declaration dates
        $period = array(
            'start_date' => $obj->start_date,
            'end_date' => $obj->end_date
        );
        
        return $this->calculateCA3Amounts($declaration_id, $period);
    }
}