<?php
require_once __DIR__ . '/../db/config.php';

class Pef {
    private $db;

    public function __construct() {
        $this->db = db();
    }

    /**
     * Get all projects, optionally filtered by industry or status.
     */
    public function getProjects(?string $industry = null, ?string $status = null): array {
        $sql = "SELECT * FROM projects WHERE 1=1";
        $params = [];
        if ($industry) {
            $sql .= " AND industry = :industry";
            $params['industry'] = $industry;
        }
        if ($status) {
            $sql .= " AND status = :status";
            $params['status'] = $status;
        }
        $sql .= " ORDER BY updated_at DESC";
        
        $stmt = $this->db->prepare($sql);
        $stmt->execute($params);
        return $stmt->fetchAll();
    }

    /**
     * User authentication.
     */
    public function login(string $username, string $password): ?array {
        $stmt = $this->db->prepare("SELECT * FROM users WHERE username = :username");
        $stmt->execute(['username' => $username]);
        $user = $stmt->fetch();

        if ($user && password_verify($password, $user['password'])) {
            unset($user['password']);
            return $user;
        }
        return null;
    }

    /**
     * Update project status or details.
     */
    public function updateProject(int $id, array $data): bool {
        $fields = [];
        foreach ($data as $key => $value) {
            $fields[] = "$key = :$key";
        }
        $sql = "UPDATE projects SET " . implode(', ', $fields) . " WHERE id = :id";
        $data['id'] = $id;
        $stmt = $this->db->prepare($sql);
        return $stmt->execute($data);
    }

    /**
     * Delete project.
     */
    public function deleteProject(int $id): bool {
        $stmt = $this->db->prepare("DELETE FROM projects WHERE id = :id");
        return $stmt->execute(['id' => $id]);
    }

    /**
     * Dashboard stats.
     */
    public function getStats(): array {
        $stats = [];
        $stats['total_projects'] = $this->db->query("SELECT COUNT(*) FROM projects")->fetchColumn();
        $stats['active_projects'] = $this->db->query("SELECT COUNT(*) FROM projects WHERE status = 'active'")->fetchColumn();
        $stats['latest_logs'] = $this->db->query("SELECT pl.*, p.name as project_name FROM project_logs pl JOIN projects p ON pl.project_id = p.id ORDER BY pl.created_at DESC LIMIT 5")->fetchAll();
        return $stats;
    }

    /**
     * Get a single project by ID.
     */
    public function getProject(int $id): ?array {
        $stmt = $this->db->prepare("SELECT * FROM projects WHERE id = :id");
        $stmt->execute(['id' => $id]);
        return $stmt->fetch() ?: null;
    }

    /**
     * Get all logs for a specific project.
     */
    public function getProjectLogs(int $projectId): array {
        $stmt = $this->db->prepare("SELECT * FROM project_logs WHERE project_id = :project_id ORDER BY created_at DESC");
        $stmt->execute(['project_id' => $projectId]);
        return $stmt->fetchAll();
    }

    /**
     * Create a new project.
     */
    public function createProject(string $name, string $description, string $industry, string $version = '1.0.0'): int {
        $stmt = $this->db->prepare("INSERT INTO projects (name, description, industry, current_version) VALUES (:name, :description, :industry, :version)");
        $stmt->execute([
            'name' => $name,
            'description' => $description,
            'industry' => $industry,
            'version' => $version
        ]);
        return (int)$this->db->lastInsertId();
    }

    /**
     * Add a log entry for a project and update its current version.
     */
    public function addLog(int $projectId, string $version, string $logEntry, string $author = 'System'): bool {
        try {
            $this->db->beginTransaction();

            $stmt = $this->db->prepare("INSERT INTO project_logs (project_id, version, log_entry, author) VALUES (:project_id, :version, :log_entry, :author)");
            $stmt->execute([
                'project_id' => $projectId,
                'version' => $version,
                'log_entry' => $logEntry,
                'author' => $author
            ]);
            
            $stmt = $this->db->prepare("UPDATE projects SET current_version = :version WHERE id = :id");
            $stmt->execute(['version' => $version, 'id' => $projectId]);

            $this->db->commit();
            return true;
        } catch (Exception $e) {
            $this->db->rollBack();
            return false;
        }
    }
}