resource "aws_s3_bucket" "logs" {
  bucket = local.logs_bucket_name

  tags = {
    role = "s3-access-logs"
  }

  lifecycle {
    prevent_destroy = true
  }
}

resource "aws_s3_bucket_public_access_block" "logs" {
  bucket = aws_s3_bucket.logs.id

  block_public_acls       = true
  block_public_policy     = true
  ignore_public_acls      = true
  restrict_public_buckets = true
}

resource "aws_s3_bucket_ownership_controls" "logs" {
  bucket = aws_s3_bucket.logs.id

  rule {
    object_ownership = "BucketOwnerEnforced"
  }
}

resource "aws_s3_bucket_server_side_encryption_configuration" "logs" {
  bucket = aws_s3_bucket.logs.id

  rule {
    apply_server_side_encryption_by_default {
      # SSE-S3 only: S3 log delivery cannot write to an SSE-KMS bucket.
      sse_algorithm = "AES256"
    }
  }
}

resource "aws_s3_bucket_lifecycle_configuration" "logs" {
  bucket = aws_s3_bucket.logs.id

  rule {
    id     = "expire-access-logs"
    status = "Enabled"

    filter {}

    expiration {
      days = 365
    }
  }
}

resource "aws_s3_bucket_policy" "logs" {
  bucket = aws_s3_bucket.logs.id

  policy = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Sid    = "S3ServerAccessLogsWrite"
        Effect = "Allow"
        Principal = {
          Service = "logging.s3.amazonaws.com"
        }
        Action   = "s3:PutObject"
        Resource = "${aws_s3_bucket.logs.arn}/s3-access/*"
        Condition = {
          ArnLike = {
            "aws:SourceArn" = aws_s3_bucket.traces.arn
          }
          StringEquals = {
            "aws:SourceAccount" = local.account_id
          }
        }
      },
      {
        Sid       = "DenyInsecureTransport"
        Effect    = "Deny"
        Principal = "*"
        Action    = "s3:*"
        Resource = [
          aws_s3_bucket.logs.arn,
          "${aws_s3_bucket.logs.arn}/*",
        ]
        Condition = {
          Bool = {
            "aws:SecureTransport" = "false"
          }
        }
      }
    ]
  })
}

resource "aws_s3_bucket" "traces" {
  bucket = local.traces_bucket_name

  lifecycle {
    prevent_destroy = true
  }
}

resource "aws_s3_bucket_public_access_block" "traces" {
  bucket = aws_s3_bucket.traces.id

  block_public_acls       = true
  block_public_policy     = true
  ignore_public_acls      = true
  restrict_public_buckets = true
}

resource "aws_s3_bucket_ownership_controls" "traces" {
  bucket = aws_s3_bucket.traces.id

  rule {
    object_ownership = "BucketOwnerEnforced"
  }
}

resource "aws_s3_bucket_versioning" "traces" {
  bucket = aws_s3_bucket.traces.id

  versioning_configuration {
    status = "Enabled"
  }
}

resource "aws_s3_bucket_server_side_encryption_configuration" "traces" {
  bucket = aws_s3_bucket.traces.id

  rule {
    apply_server_side_encryption_by_default {
      sse_algorithm     = "aws:kms"
      kms_master_key_id = aws_kms_key.traces.arn
    }
    bucket_key_enabled = true
  }
}

resource "aws_s3_bucket_lifecycle_configuration" "traces" {
  bucket = aws_s3_bucket.traces.id

  rule {
    id     = "archive-exports-to-deep-archive"
    status = "Enabled"

    filter {
      prefix = var.export_prefix
    }

    transition {
      days          = 90
      storage_class = "DEEP_ARCHIVE"
    }
  }

  rule {
    id     = "expire-noncurrent-versions"
    status = "Enabled"

    filter {}

    noncurrent_version_expiration {
      noncurrent_days = 90
    }
  }

  rule {
    id     = "abort-incomplete-multipart"
    status = "Enabled"

    filter {}

    abort_incomplete_multipart_upload {
      days_after_initiation = 7
    }
  }
}

resource "aws_s3_bucket_logging" "traces" {
  bucket = aws_s3_bucket.traces.id

  target_bucket = aws_s3_bucket.logs.id
  target_prefix = "s3-access/"

  depends_on = [aws_s3_bucket_policy.logs]
}

resource "aws_s3_bucket_policy" "traces" {
  bucket = aws_s3_bucket.traces.id

  # No SSE-header enforcement Deny. LangSmith's exporter does not send an
  # "aws:kms" SSE header, so a "must be aws:kms" Deny blocks its writes — and
  # StringNotEqualsIfExists on a Deny also blocks header-less puts. Encryption
  # is guaranteed by the bucket DEFAULT (SSE-KMS with our CMK).
  policy = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Sid       = "DenyInsecureTransport"
        Effect    = "Deny"
        Principal = "*"
        Action    = "s3:*"
        Resource = [
          aws_s3_bucket.traces.arn,
          "${aws_s3_bucket.traces.arn}/*",
        ]
        Condition = {
          Bool = {
            "aws:SecureTransport" = "false"
          }
        }
      }
    ]
  })
}