/*
* Copyright @ 2013 CurisTEC, S.A.S. All Rights Reserved.
*/
package net.curisit.securis.db;

import java.io.Serializable;
import java.util.Date;

import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.EntityManager;
import jakarta.persistence.Id;
import jakarta.persistence.JoinColumn;
import jakarta.persistence.ManyToOne;
import jakarta.persistence.Table;

import net.curisit.integrity.commons.Utils;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.annotation.JsonProperty;

/**
* BlockedRequest
* <p>
* Persistent record marking a request (by hash) as blocked.
* Primary key is the SHA-256 of the original request_data.
* Useful to avoid replay/duplicate processing.
*
* Mapping details:
* - Table: blocked_request
* - PK: hash (SHA-256(request_data))
* - Optional relation 'blockedBy' for auditing.
*
* @author JRA
* Last reviewed by JRA on Oct 7, 2025.
*/
@JsonAutoDetect
@JsonInclude(Include.NON_NULL)
@Entity
@Table(name = "blocked_request")
@JsonIgnoreProperties(ignoreUnknown = true)
public class BlockedRequest implements Serializable {

    private static final long serialVersionUID = 1L;

    /** Unique SHA-256 hash of {@link #requestData}. */
    @Id
    private String hash;

    /** Original request payload. */
    @Column(name = "request_data")
    @JsonProperty("request_data")
    private String requestData;

    /** Server-side creation timestamp. */
    @Column(name = "creation_timestamp")
    @JsonProperty("creation_timestamp")
    private Date creationTimestamp;

    /** User who blocked this request (optional, auditing). */
    @JsonIgnore
    @ManyToOne
    @JoinColumn(name = "blocked_by")
    private User blockedBy;

    // ---------------------------------------------------------------------
    // Getters & setters
    // ---------------------------------------------------------------------

    /**
    * getCreationTimestamp<p>
    * Get the creation timestamp.
    *
    * @return creationTimestamp
    */
    public Date getCreationTimestamp() { return creationTimestamp; }

    /**
    * setCreationTimestamp<p>
    * Set the creation timestamp.
    *
    * @param creationTimestamp
    */
    public void setCreationTimestamp(Date creationTimestamp) { this.creationTimestamp = creationTimestamp; }

    /**
    * equals<p>
    * Identity based on primary key (hash).
    */
    @Override
    public boolean equals(Object obj) {
        if (!(obj instanceof BlockedRequest)) return false;
        BlockedRequest other = (BlockedRequest) obj;
        return (hash == null && other.hash == null) || (hash != null && hash.equals(other.hash));
    }

    /**
    * hashCode<p>
    * Hash based on primary key (hash).
    */
    @Override
    public int hashCode() { return (hash == null ? 0 : hash.hashCode()); }

    /**
    * getRequestData<p>
    * Get the original serialized request data.
    *
    * @return requestData
    */
    public String getRequestData() { return requestData; }

    /**
    * setRequestData<p>
    * Set the original request data and recompute the PK hash immediately.
    * Hash is computed as SHA-256 over the request string.
    *
    * @param requestData
    */
    public void setRequestData(String requestData) {
        this.requestData = requestData;
        this.hash = generateHash(this.requestData);
    }

    /**
    * getBlockedBy<p>
    * Return the user who blocked this request (if any).
    *
    * @return blockedBy
    */
    public User getBlockedBy() { return blockedBy; }

    /**
    * setBlockedBy<p>
    * Set the user who blocked this request.
    *
    * @param blockedBy
    */
    public void setBlockedBy(User blockedBy) { this.blockedBy = blockedBy; }

    // ---------------------------------------------------------------------
    // Static helpers
    // ---------------------------------------------------------------------

    /**
    * generateHash<p>
    * Compute the SHA-256 hex string for the given request data.
    *
    * @param reqData
    * @return sha256(reqData) or null if reqData is null
    */
    public static String generateHash(String reqData) {
        return (reqData != null ? Utils.sha256(reqData) : null);
    }

    /**
    * isRequestBlocked<p>
    * Check if a request payload is blocked by looking up its hash as the PK.
    *
    * @param requestData original payload
    * @param em JPA entity manager
    * @return true if an entry exists with the same hash
    */
    public static boolean isRequestBlocked(String requestData, EntityManager em) {
        String hash = generateHash(requestData);
        BlockedRequest br = em.find(BlockedRequest.class, hash);
        return br != null;
    }
}