"""仅上传调用方显式提供的单个 PNG 的窄 EvidenceSink。"""

from __future__ import annotations

from cmbuyer_client.core.errors import AmbiguousRemoteError, ProtocolRemoteError, ValidationError
from cmbuyer_client.core.models import AssetReceipt, DeviceCredentials, EvidenceUpload
from cmbuyer_client.core.validation import rfc3339_z_nanoseconds

from .http_transport import HttpTransport
from .wire import SMALL_RESPONSE_LIMIT, classify_bodyless_error, common_headers, parse_json_response


class HttpEvidenceSink:
    def __init__(self, transport: HttpTransport) -> None:
        self._transport = transport

    def upload(self, credentials: DeviceCredentials, evidence: EvidenceUpload) -> AssetReceipt:
        boundary = "cmbuyer-" + evidence.upload_key.replace("-", "")
        marker = ("--" + boundary).encode("ascii")
        if marker in evidence.content:
            raise ProtocolRemoteError("multipart_boundary_collision")
        body = _multipart_body(boundary, evidence)
        response = self._transport.request(
            "POST",
            f"/api/v1/tasks/{evidence.task_id}/evidence",
            common_headers(
                credentials.device_id,
                credentials.token.value,
                "multipart/form-data; boundary=" + boundary,
            ),
            body,
            response_limit=SMALL_RESPONSE_LIMIT,
        )
        if response.status not in (200, 201):
            classify_bodyless_error(response)
        try:
            receipt = AssetReceipt.from_wire(parse_json_response(response, maximum=SMALL_RESPONSE_LIMIT))
        except ValidationError as error:
            raise AmbiguousRemoteError("invalid_evidence_success_response") from error
        if (
            receipt.task_id != evidence.task_id
            or receipt.attempt_id != evidence.attempt_id
            or receipt.kind != evidence.kind
            or receipt.privacy_tier != evidence.privacy_tier
            or receipt.sha256 != evidence.sha256
            or receipt.byte_size != len(evidence.content)
            or receipt.width_px != evidence.width_px
            or receipt.height_px != evidence.height_px
            or rfc3339_z_nanoseconds(receipt.captured_at) != rfc3339_z_nanoseconds(evidence.captured_at)
        ):
            raise AmbiguousRemoteError("evidence_response_mismatch")
        return receipt


def _multipart_body(boundary: str, evidence: EvidenceUpload) -> bytes:
    chunks: list[bytes] = []

    def add_field(name: str, value: str) -> None:
        chunks.extend(
            (
                f"--{boundary}\r\n".encode("ascii"),
                f'Content-Disposition: form-data; name="{name}"\r\n\r\n'.encode("ascii"),
                value.encode("utf-8"),
                b"\r\n",
            )
        )

    add_field("upload_key", evidence.upload_key)
    add_field("attempt_id", evidence.attempt_id)
    add_field("kind", evidence.kind)
    add_field("privacy_tier", evidence.privacy_tier)
    add_field("sha256", evidence.sha256)
    add_field("captured_at", evidence.captured_at)
    chunks.extend(
        (
            f"--{boundary}\r\n".encode("ascii"),
            b'Content-Disposition: form-data; name="file"; filename="evidence.png"\r\n',
            b"Content-Type: image/png\r\n\r\n",
            evidence.content,
            b"\r\n",
            f"--{boundary}--\r\n".encode("ascii"),
        )
    )
    return b"".join(chunks)