package org.whispersystems.textsecuregcm.controllers;

import org.whispersystems.textsecuregcm.entities.StickerPackFormUploadAttributes;
import org.whispersystems.textsecuregcm.entities.StickerPackFormUploadAttributes.StickerPackFormUploadItem;
import org.whispersystems.textsecuregcm.limits.RateLimiters;
import org.whispersystems.textsecuregcm.s3.PolicySigner;
import org.whispersystems.textsecuregcm.s3.PostPolicyGenerator;
import org.whispersystems.textsecuregcm.storage.Account;
import org.whispersystems.textsecuregcm.util.Hex;
import org.whispersystems.textsecuregcm.util.Pair;

import javax.validation.constraints.Max;
import javax.validation.constraints.Min;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import java.security.SecureRandom;
import java.time.ZoneOffset;
import java.time.ZonedDateTime;
import java.util.LinkedList;
import java.util.List;

import io.dropwizard.auth.Auth;

@Path("/v1/sticker")
public class StickerController {

  private final RateLimiters        rateLimiters;
  private final PolicySigner        policySigner;
  private final PostPolicyGenerator policyGenerator;

  public StickerController(RateLimiters rateLimiters, String accessKey, String accessSecret, String region, String bucket) {
    this.rateLimiters    = rateLimiters;
    this.policySigner    = new PolicySigner(accessSecret, region);
    this.policyGenerator = new PostPolicyGenerator(region, bucket, accessKey);
  }

  @GET
  @Produces(MediaType.APPLICATION_JSON)
  @Path("/pack/form/{count}")
  public StickerPackFormUploadAttributes getStickersForm(@Auth Account account,
                                                         @PathParam("count") @Min(1) @Max(201) int stickerCount)
      throws RateLimitExceededException
  {
    rateLimiters.getStickerPackLimiter().validate(account.getNumber());

    ZonedDateTime             now               = ZonedDateTime.now(ZoneOffset.UTC);
    String                    packId            = generatePackId();
    String                    packLocation      = "stickers/" + packId;
    String                    manifestKey       = packLocation + "/manifest.proto";
    Pair<String, String>      manifestPolicy    = policyGenerator.createFor(now, manifestKey, 10240);
    String                    manifestSignature = policySigner.getSignature(now, manifestPolicy.second());
    StickerPackFormUploadItem manifest          = new StickerPackFormUploadItem(-1, manifestKey, manifestPolicy.first(), "private", "AWS4-HMAC-SHA256",
                                                                                now.format(PostPolicyGenerator.AWS_DATE_TIME), manifestPolicy.second(), manifestSignature);


    List<StickerPackFormUploadItem> stickers = new LinkedList<>();

    for (int i=0;i<stickerCount;i++) {
      String               stickerKey       = packLocation + "/full/" + i;
      Pair<String, String> stickerPolicy    = policyGenerator.createFor(now, stickerKey, 100155);
      String               stickerSignature = policySigner.getSignature(now, stickerPolicy.second());
      stickers.add(new StickerPackFormUploadItem(i, stickerKey, stickerPolicy.first(), "private", "AWS4-HMAC-SHA256",
                                                 now.format(PostPolicyGenerator.AWS_DATE_TIME), stickerPolicy.second(), stickerSignature));
    }

    return new StickerPackFormUploadAttributes(packId, manifest, stickers);
  }

  private String generatePackId() {
    byte[] object = new byte[16];
    new SecureRandom().nextBytes(object);

    return Hex.toStringCondensed(object);
  }

}