from io import BytesIO
from datetime import datetime, timezone
from copy import deepcopy

import requests
from requests.auth import HTTPBasicAuth
from django.conf import settings
from django.utils.text import slugify

from labs.models import (
    CertificateRecipient,
    CertificateType,
    CertificateIssuance,
    CertLMSLearner,
)
from labs.certificate.file import deprecated_upload_certificate_file_to_aliyun_oss


EXAMS = {
    "Practitioner": {
        "exam_id_list": ["288", "286", "302"],
        "name": "TiDB Practitioner",
    },
    "PCTA_v6": {
        "exam_id_list": ["189", "237", "266", "196", "271", "280", "307"],
        "name": "TiDB Associate v6",
    },
    "PCTP_v6": {
        "exam_id_list": ["220", "253", "301", "270", "295", "268", "319"],
        "name": "TiDB Professional Database Administrator v6",
    },
    "PCSD_v6": {
        "exam_id_list": ["251", "252", "267", "318"],
        "name": "TiDB SQL Developer",
    },
    "PCTM_v6": {"exam_id_list": [], "name": "TiDB Master Database Administrator v6"},
}


TLMS_COURSE_EXAMP_MAP = {}

for cert_short_name, cert_metadata in EXAMS.items():
    for e_id in cert_metadata["exam_id_list"]:
        TLMS_COURSE_EXAMP_MAP[e_id] = {
            "cert_short_name": cert_short_name,
            "cert_name": cert_metadata["name"],
        }


def get_tlms_user_info(tlms_user_id: str) -> dict:
    url = f"https://edu.pingcap.com/api/v1/users/id:{tlms_user_id}"
    response = requests.get(url, auth=HTTPBasicAuth(settings.TLMS_API_KEY, ""))
    response.raise_for_status()
    return response.json()


def sync_tlms_certificates_for_user(tlms_user_info: dict):
    tlms_user_id = tlms_user_info["id"]
    tlms_certifications: list = tlms_user_info["certifications"]

    external_user_info = deepcopy(tlms_user_info)
    for key in [
        "login_key",
        "courses",
        "branches",
        "groups",
        "certifications",
        "badges",
    ]:
        del external_user_info[key]

    try:
        deprecated_learner = CertLMSLearner.objects.get(user_id=tlms_user_id)
        user_gid = deprecated_learner.user_gid
    except CertLMSLearner.DoesNotExist:
        user_gid = None

    try:
        cert_recipient = CertificateRecipient.objects.get(
            external_user_info__id=tlms_user_id
        )
    except CertificateRecipient.DoesNotExist:
        cert_recipient = CertificateRecipient.objects.create(
            first_name=tlms_user_info["first_name"],
            last_name=tlms_user_info["last_name"],
            email=tlms_user_info["email"],
            email_verified=True,
            country=tlms_user_info["custom_field_1"],
            company_name=tlms_user_info["custom_field_2"],
            external_user_info=external_user_info,
            deprecated_gid=user_gid,
        )

    for certification in tlms_certifications:
        course_id = certification["course_id"]
        cert_number = certification["unique_id"]
        issued_date = certification["issued_date"]
        issued_date_timestamp = certification["issued_date_timestamp"]
        issued_at = datetime.strptime(issued_date, "%d/%m/%Y").replace(tzinfo=timezone.utc)
        tlms_cert_file_public_url = certification["public_url"]
        if course_id not in TLMS_COURSE_EXAMP_MAP:
            continue
        cert_info = TLMS_COURSE_EXAMP_MAP[course_id]
        cert_name = cert_info["cert_name"]
        cert_short_name = cert_info["cert_short_name"]
        cert_type, created = CertificateType.objects.get_or_create(
            name=cert_name,
            short_name=cert_short_name,
            defaults={
                "issuer_name": "PingCAP",
                "issuer_website": "https://www.pingcap.com/education/",
            },
        )

        issuance, created = CertificateIssuance.objects.get_or_create(
            recipient=cert_recipient,
            cert_type=cert_type,
            cert_number=cert_number,
            defaults={
                "cert_snapshot": {
                    "first_name": cert_recipient.first_name,
                    "last_name": cert_recipient.last_name,
                    "cert_name": cert_name,
                    "cert_short_name": cert_short_name,
                    "issued_date": issued_date,
                    "issued_date_timestamp": issued_date_timestamp,
                    "tlms_cert_public_url": tlms_cert_file_public_url,
                },
                "issued_at": issued_at,
                "tlms_course_id": course_id,
            },
        )
        if created:
            response = requests.get(tlms_cert_file_public_url)
            response.raise_for_status()
            pdf_file = BytesIO(response.content)
            if pdf_file.getbuffer().nbytes < 1024 * 100:
                raise Exception(
                    f"PDF file is too small: {pdf_file.getbuffer().nbytes} bytes, "
                    "this usally means we did not get correct PDF file from TLMS"
                )
            pdf_file_path = (
                f"certificates/{slugify(f'{cert_short_name}_{cert_number}')}.pdf"
            )
            issuance.file_storage_provider = "aliyun"
            issuance.file_bucket = settings.ALIYUN_OSS_BUCKET
            issuance.file_object_key = pdf_file_path
            issuance.file_content_type = "application/pdf"
            deprecated_upload_certificate_file_to_aliyun_oss(pdf_file_path, pdf_file)
            issuance.save()