"""Ribbon / Sonus PSX or EMA preset — REST API pull.

Ribbon's Element Management Application (EMA) and PSX both expose CDR
export APIs. The common path is ``/rest/cdrs`` with basic auth. Output
format varies: CSV (EMA default) or XML (PSX default); we request CSV
and feed the generic_csv adapter.
"""

from __future__ import annotations

import base64
import urllib.parse
import urllib.request
from datetime import datetime, timedelta
from typing import Iterable, Optional

from .base import BasePreset, CredentialField, FetchedFile


class RibbonPreset(BasePreset):
    PRESET_SLUG = "ribbon"
    LABEL = "Ribbon / Sonus SBC (EMA / PSX)"
    CDR_FORMAT = "generic_csv"
    TRANSPORT_METHOD = "api"
    DEFAULT_CRON = "0 3 * * *"

    CREDENTIAL_FIELDS = (
        CredentialField("api_host", "EMA / PSX host", "text",
                        help="e.g. https://ema.example.com"),
        CredentialField("username", "API username", "text"),
        CredentialField("password", "API password", "password", sensitive=True),
    )

    FORMAT_CONFIG = {
        "start_time":    "startTime",
        "caller_number": "callingNumber",
        "called_number": "calledNumber",
        "duration_sec":  "callDurationSeconds",
        "billed_amount": "totalCharge",
        "call_id":       "globalCallId",
        "trunk_group":   "ingressTrunkGroup",
        "disposition":   "releaseCause",
        "ts_format":     "%Y-%m-%dT%H:%M:%S%z",
    }

    def _auth_header(self, cfg: dict, secrets: dict) -> str:
        creds = base64.b64encode(
            f"{cfg['username']}:{secrets['password']}".encode("utf-8")
        ).decode("ascii")
        return f"Basic {creds}"

    def _request(self, url: str, headers: dict) -> bytes:
        req = urllib.request.Request(url, headers=headers)
        with urllib.request.urlopen(req, timeout=60) as resp:
            return resp.read()

    def validate(self, profile_config: dict, secrets: dict) -> tuple[bool, str]:
        try:
            base = profile_config["api_host"].rstrip("/")
            self._request(
                f"{base}/rest/v1/system/status",
                headers={"Authorization": self._auth_header(profile_config, secrets)},
            )
            return True, "EMA/PSX reachable"
        except Exception as exc:
            return False, f"Ribbon validate failed: {exc}"

    def fetch(
        self,
        profile_config: dict,
        secrets: dict,
        since: Optional[datetime],
    ) -> Iterable[FetchedFile]:
        base = profile_config["api_host"].rstrip("/")
        since = since or (datetime.utcnow() - timedelta(days=1))
        end = datetime.utcnow()
        qs = urllib.parse.urlencode({
            "startTime": since.strftime("%Y-%m-%dT%H:%M:%SZ"),
            "endTime":   end.strftime("%Y-%m-%dT%H:%M:%SZ"),
            "format":    "csv",
        })
        headers = {
            "Authorization": self._auth_header(profile_config, secrets),
            "Accept": "text/csv",
        }
        content = self._request(f"{base}/rest/v1/cdrs?{qs}", headers=headers)
        yield FetchedFile(
            remote_path=f"ribbon_cdrs_{end:%Y%m%dT%H%M%SZ}.csv",
            mtime=end, content=content, size_bytes=len(content),
        )