"""Direct ADT HTTP access. Only for teardown (deletion). The model never uses it.

Credentials come from the environment (or .env): A4H_URL, A4H_USER, A4H_PASSWORD, A4H_CLIENT.
"""
import base64
import http.cookiejar
import os
import re
import urllib.request
from xml.sax.saxutils import quoteattr

DEL_REQ = "application/vnd.sap.adt.deletion.request.v1+xml"
DEL_RES = "application/vnd.sap.adt.deletion.response.v1+xml"


def load_env(path=".env"):
    if os.path.exists(path):
        for line in open(path):
            line = line.strip()
            if line and not line.startswith("#") and "=" in line:
                k, v = line.split("=", 1)
                os.environ.setdefault(k.strip(), v.strip())


class AdtClient:
    def __init__(self):
        load_env()
        self.base = os.environ["A4H_URL"].rstrip("/")
        self.client = os.environ.get("A4H_CLIENT", "001")
        auth = f'{os.environ["A4H_USER"]}:{os.environ["A4H_PASSWORD"]}'
        self.auth = "Basic " + base64.b64encode(auth.encode()).decode()
        self.opener = urllib.request.build_opener(
            urllib.request.HTTPCookieProcessor(http.cookiejar.CookieJar()))
        self.csrf = None

    def _req(self, method, path, body=None, headers=None):
        url = f"{self.base}{path}{'&' if '?' in path else '?'}sap-client={self.client}"
        h = {"Authorization": self.auth}
        if self.csrf:
            h["x-csrf-token"] = self.csrf
        h.update(headers or {})
        req = urllib.request.Request(url, body.encode() if body else None, h, method=method)
        with self.opener.open(req, timeout=300) as r:
            return r.status, dict(r.headers), r.read().decode()

    def fetch_csrf(self):
        _, hdr, _ = self._req("GET", "/sap/bc/adt/discovery",
                              headers={"x-csrf-token": "fetch", "Accept": "*/*"})
        self.csrf = hdr.get("x-csrf-token") or hdr.get("X-CSRF-Token")

    def delete(self, uris):
        """Delete objects by ADT URI. Returns {uri: (deleted, message)}."""
        if not uris:
            return {}
        if not self.csrf:
            self.fetch_csrf()
        objs = "".join(f"<del:object adtcore:uri={quoteattr(u)}><del:transportNumber/></del:object>"
                       for u in uris)
        body = ('<?xml version="1.0" encoding="UTF-8"?>'
                '<del:deletionRequest xmlns:del="http://www.sap.com/adt/deletion" '
                'xmlns:adtcore="http://www.sap.com/adt/core">' + objs + '</del:deletionRequest>')
        _, _, text = self._req("POST", "/sap/bc/adt/deletion/delete", body,
                               {"Content-Type": DEL_REQ, "Accept": DEL_RES})
        out = {}
        for m in re.finditer(r'<del:object\b([^>]*)>(.*?)</del:object>', text, re.S):
            attrs, inner = m.group(1), m.group(2)
            uri = re.search(r'adtcore:uri="([^"]+)"', attrs)
            ok = re.search(r'del:isDeleted="([^"]+)"', attrs)
            msg = re.search(r'<del:text>(.*?)</del:text>', inner, re.S)
            out[uri.group(1) if uri else "?"] = (ok is not None and ok.group(1) == "true",
                                                 msg.group(1) if msg else "")
        return out