<?php

namespace App\Models;

use App\Core\Database;
use PDO;
// Import PDO for type hinting if needed, though Database class abstracts it

class Employee
{
    private Database $db;
    private string $table_name = "employees";

    // Employee properties (matching table columns)
    public ?int $id = null;
    public string $employee_code;
    public string $chat_user_id;
    public string $first_name;
    public string $last_name;
    public string $email;
    public ?int $manager_id = null;
    public bool $is_manager = false;
    public bool $is_hr = false;
    public ?string $created_at = null;
    public ?string $updated_at = null;

    /**
     * @param Database $db
     */
    public function __construct(?Database $db = null)
    {
        $this->db = $db ?: Database::getInstance();
    }

    // Setter methods for properties to allow chaining or validation if needed
    /**
     * @param int $id
     * @return mixed
     */
    public function setId(int $id): self
    {
        $this->id = $id;
        return $this;
    }

    /**
     * @param string $employee_code
     * @return mixed
     */
    public function setEmployeeCode(string $employee_code): self
    {
        $this->employee_code = $employee_code;
        return $this;
    }

    /**
     * @param string $chat_user_id
     * @return mixed
     */
    public function setChatUserId(string $chat_user_id): self
    {
        $this->chat_user_id = $chat_user_id;
        return $this;
    }

    /**
     * @param string $first_name
     * @return mixed
     */
    public function setFirstName(string $first_name): self
    {
        $this->first_name = $first_name;
        return $this;
    }

    /**
     * @param string $last_name
     * @return mixed
     */
    public function setLastName(string $last_name): self
    {
        $this->last_name = $last_name;
        return $this;
    }

    /**
     * @param string $email
     * @return mixed
     */
    public function setEmail(string $email): self
    {
        $this->email = $email;
        return $this;
    }

    /**
     * @param int $manager_id
     * @return mixed
     */
    public function setManagerId(?int $manager_id): self
    {
        $this->manager_id = $manager_id;
        return $this;
    }

    /**
     * @param bool $is_manager
     * @return mixed
     */
    public function setIsManager(bool $is_manager): self
    {
        $this->is_manager = $is_manager;
        return $this;
    }

    /**
     * @param bool $is_hr
     * @return mixed
     */
    public function setIsHr(bool $is_hr): self
    {
        $this->is_hr = $is_hr;
        return $this;
    }

    /**
     * Create a new employee record in the database.
     * @return bool True on success, false on failure.
     */
    public function create(): bool
    {
        $query = "INSERT INTO {$this->table_name}
                    (employee_code, chat_user_id, first_name, last_name, email, manager_id, is_manager, is_hr)
                  VALUES
                    (:employee_code, :chat_user_id, :first_name, :last_name, :email, :manager_id, :is_manager, :is_hr)";

        $this->db->query($query);
        $this->db->bind(':employee_code', $this->employee_code);
        $this->db->bind(':chat_user_id', $this->chat_user_id);
        $this->db->bind(':first_name', $this->first_name);
        $this->db->bind(':last_name', $this->last_name);
        $this->db->bind(':email', $this->email);
        $this->db->bind(':manager_id', $this->manager_id, $this->manager_id === null ? PDO::PARAM_NULL : PDO::PARAM_INT);
        $this->db->bind(':is_manager', $this->is_manager, PDO::PARAM_BOOL);
        $this->db->bind(':is_hr', $this->is_hr, PDO::PARAM_BOOL);

        if ($this->db->execute()) {
            $this->id = (int) $this->db->lastInsertId();
            return true;
        }
        return false;
    }

    /**
     * Read all employees or a single employee by ID.
     * @param ?int $id If null, fetches all employees. Otherwise, fetches employee by this ID.
     * @return array|object|false Array of employees, a single employee object, or false on failure/not found.
     */
    public function read(?int $id = null)
    {
        if ($id !== null) {
            // Read single employee
            $query = "SELECT * FROM {$this->table_name} WHERE id = :id LIMIT 1";
            $this->db->query($query);
            $this->db->bind(':id', $id, PDO::PARAM_INT);
            $row = $this->db->single();
            if ($row) {
                // Populate object properties from the row
                $this->id = (int) $row['id'];
                $this->employee_code = $row['employee_code'];
                $this->chat_user_id = $row['chat_user_id'];
                $this->first_name = $row['first_name'];
                $this->last_name = $row['last_name'];
                $this->email = $row['email'];
                $this->manager_id = $row['manager_id'] ? (int) $row['manager_id'] : null;
                $this->is_manager = (bool) $row['is_manager'];
                $this->is_hr = (bool) $row['is_hr'];
                $this->created_at = $row['created_at'];
                $this->updated_at = $row['updated_at'];
                return $this; // Return the populated object
            }
            return false;
        } else {
            // Read all employees
            $query = "SELECT * FROM {$this->table_name} ORDER BY created_at DESC";
            $this->db->query($query);
            return $this->db->resultSet();
        }
    }

    /**
     * Find an employee by their chat_user_id.
     * @param string $chatUserId The chat_user_id to search for.
     * @return self|false The Employee object if found, otherwise false.
     */
    public function findByChatUserId(string $chatUserId)
    {
        $query = "SELECT * FROM {$this->table_name} WHERE chat_user_id = :chat_user_id LIMIT 1";
        $this->db->query($query);
        $this->db->bind(':chat_user_id', $chatUserId);
        $row = $this->db->single();

        if ($row) {
            $this->id = (int) $row['id'];
            $this->employee_code = $row['employee_code'];
            $this->chat_user_id = $row['chat_user_id'];
            $this->first_name = $row['first_name'];
            $this->last_name = $row['last_name'];
            $this->email = $row['email'];
            $this->manager_id = $row['manager_id'] ? (int) $row['manager_id'] : null;
            $this->is_manager = (bool) $row['is_manager'];
            $this->is_hr = (bool) $row['is_hr'];
            $this->created_at = $row['created_at'];
            $this->updated_at = $row['updated_at'];
            return $this;
        }
        return false;
    }

    /**
     * Update an existing employee record in the database.
     * Assumes $this->id is set.
     * @return bool True on success, false on failure.
     */
    public function update(): bool
    {
        if ($this->id === null) {
            return false; // Cannot update without an ID
        }
        $query = "UPDATE {$this->table_name} SET
                    employee_code = :employee_code,
                    chat_user_id = :chat_user_id,
                    first_name = :first_name,
                    last_name = :last_name,
                    email = :email,
                    manager_id = :manager_id,
                    is_manager = :is_manager,
                    is_hr = :is_hr
                  WHERE id = :id";

        $this->db->query($query);
        $this->db->bind(':id', $this->id, PDO::PARAM_INT);
        $this->db->bind(':employee_code', $this->employee_code);
        $this->db->bind(':chat_user_id', $this->chat_user_id);
        $this->db->bind(':first_name', $this->first_name);
        $this->db->bind(':last_name', $this->last_name);
        $this->db->bind(':email', $this->email);
        $this->db->bind(':manager_id', $this->manager_id, $this->manager_id === null ? PDO::PARAM_NULL : PDO::PARAM_INT);
        $this->db->bind(':is_manager', $this->is_manager, PDO::PARAM_BOOL);
        $this->db->bind(':is_hr', $this->is_hr, PDO::PARAM_BOOL);

        return $this->db->execute();
    }

    /**
     * Delete an employee record from the database.
     * Can delete by current object's ID or a specific ID.
     * @param ?int $id If null, uses $this->id. Otherwise, uses the provided ID.
     * @return bool True on success, false on failure.
     */
    public function delete(?int $id = null): bool
    {
        $id_to_delete = $id ?? $this->id;
        if ($id_to_delete === null) {
            return false; // Cannot delete without an ID
        }

        $query = "DELETE FROM {$this->table_name} WHERE id = :id";
        $this->db->query($query);
        $this->db->bind(':id', $id_to_delete, PDO::PARAM_INT);

        return $this->db->execute();
    }
}