"""
orgstate_client.client — the SDK's only public class.

The Client is tenant-scoped at construction (the customer holds one
API key, tied to one tenant; an SDK that requires passing tenant_id
on every call would be needlessly chatty). For admin keys you can
pass tenant_id=None and override via the per-method ``tenant_id``
argument, but the customer-shaped use case is the default.

Transport is injectable:

  - default: stdlib urllib (no extra deps in production)
  - tests: any object with ``.request(method, url, headers=...,
    params=..., json=...)`` returning something with .status_code,
    .json(), .text — httpx.Client and fastapi.TestClient both fit

That seam lets tests run against a real FastAPI app via TestClient
without spinning up a real socket.
"""
from __future__ import annotations

import json as _json
import urllib.error
import urllib.parse
import urllib.request
from typing import Any, Dict, Optional


class ClientError(Exception):
    """Raised when the API returns an error response. Carries the
    parsed JSON body when available so the caller can branch on
    ``error.code``."""

    def __init__(self, status_code: int, body: Any):
        self.status_code = status_code
        self.body = body
        msg = (
            body.get("error", {}).get("message", str(body))
            if isinstance(body, dict) else str(body)
        )
        super().__init__(f"HTTP {status_code}: {msg}")


class _UrllibResponse:
    """Thin adapter — mirrors the bits of httpx.Response the SDK uses."""

    def __init__(self, status_code: int, body_bytes: bytes,
                  content_type: str):
        self.status_code = status_code
        self._body = body_bytes
        self._content_type = content_type

    @property
    def text(self) -> str:
        return self._body.decode("utf-8")

    def json(self) -> Any:
        return _json.loads(self._body) if self._body else None


class _UrllibTransport:
    """Default transport — stdlib only. Compatible-ish with httpx.Client
    for the small surface the SDK needs (just ``.request``)."""

    def __init__(self, base_url: str, timeout: float = 30.0):
        self.base_url = base_url.rstrip("/")
        self.timeout = timeout

    def request(self, method: str, url: str, *,
                 headers: Optional[Dict[str, str]] = None,
                 params: Optional[Dict[str, Any]] = None,
                 json: Any = None):
        # url may be absolute (test passes httpx-style) or path-only
        # — normalize against base_url
        if url.startswith(("http://", "https://")):
            full = url
        else:
            full = self.base_url + url
        if params:
            qs = urllib.parse.urlencode(
                {k: v for k, v in params.items() if v is not None}
            )
            if qs:
                full = full + ("&" if "?" in full else "?") + qs
        body: Optional[bytes] = None
        h = dict(headers or {})
        if json is not None:
            body = _json.dumps(json).encode("utf-8")
            h.setdefault("Content-Type", "application/json")
        req = urllib.request.Request(full, data=body, method=method,
                                       headers=h)
        try:
            with urllib.request.urlopen(req, timeout=self.timeout) as resp:
                return _UrllibResponse(
                    status_code=resp.status,
                    body_bytes=resp.read(),
                    content_type=resp.headers.get("content-type", ""),
                )
        except urllib.error.HTTPError as e:
            # 4xx/5xx — return as a response so the SDK can wrap
            body_bytes = e.read() if e.fp else b""
            return _UrllibResponse(
                status_code=e.code,
                body_bytes=body_bytes,
                content_type=e.headers.get("content-type", "")
                              if e.headers else "",
            )


class Client:
    """Tenant-scoped read-only SDK over the OrgState HTTP API.

    Stage 62 covers the customer-shaped read surface. Future stages
    add write methods (set_overrides, recalibrate) and admin methods
    (cross-tenant list, etc.)."""

    def __init__(self, *,
                 base_url: str,
                 tenant_id: str,
                 api_key: str,
                 transport: Any = None,
                 timeout: float = 30.0):
        self.base_url = base_url.rstrip("/")
        self.tenant_id = tenant_id
        self.api_key = api_key
        self.transport = transport or _UrllibTransport(
            base_url, timeout=timeout,
        )

    # --- internals ---------------------------------------------------

    def _request(self, method: str, path: str, *,
                  params: Optional[Dict[str, Any]] = None,
                  json: Any = None) -> Any:
        """Issue a request through the transport, raise ClientError on
        non-2xx, return the parsed response object so callers can
        decide whether they want .json() or .text."""
        headers = {"Authorization": f"Bearer {self.api_key}"}
        # for the default transport, path is enough; for httpx-style
        # transports (TestClient), pass the path as-is — TestClient
        # joins it with its own base_url
        url = path if hasattr(self.transport, "_base_url") else path
        resp = self.transport.request(
            method, url, headers=headers, params=params, json=json,
        )
        if not (200 <= resp.status_code < 300):
            try:
                body = resp.json()
            except Exception:
                body = resp.text
            raise ClientError(resp.status_code, body)
        return resp

    # --- read surface ------------------------------------------------

    def health(self) -> dict:
        """GET /tenants/{tid}/health — the readiness state for the
        tenant. Returns the same payload as Stage 34.

        **503 is a normal response**, not an error: the endpoint
        follows the k8s readiness convention where 503 means "not
        ready" (carrying the payload that explains why). The SDK
        returns the body in both cases — the caller branches on
        ``payload["healthy"]``, not on a raised exception. Other
        4xx (401 no key, 403 cross-tenant) still raise."""
        # bypass _request's non-2xx raising for this one route
        headers = {"Authorization": f"Bearer {self.api_key}"}
        resp = self.transport.request(
            "GET", f"/tenants/{self.tenant_id}/health",
            headers=headers, params=None, json=None,
        )
        if resp.status_code in (200, 503):
            return resp.json()
        # 401/403/404 etc. — those genuinely are errors
        try:
            body = resp.json()
        except Exception:
            body = resp.text
        raise ClientError(resp.status_code, body)

    def list_runs(self, *,
                   entity_type: Optional[str] = None,
                   since: Optional[str] = None,
                   limit: int = 50,
                   offset: int = 0) -> dict:
        """GET /tenants/{tid}/runs — same filters as the JSON variant
        of Stage 49."""
        # filter None at construction — httpx serializes None as the
        # literal string "None", which FastAPI then treats as the
        # filter value (matching no rows). Building the dict
        # selectively avoids the transport-level None-handling
        # difference between urllib and httpx.
        params: Dict[str, Any] = {"limit": limit, "offset": offset}
        if entity_type is not None:
            params["entity_type"] = entity_type
        if since is not None:
            params["since"] = since
        return self._request(
            "GET", f"/tenants/{self.tenant_id}/runs", params=params,
        ).json()

    def get_run(self, run_id: str) -> dict:
        """GET /runs/{run_id} — the run detail row."""
        return self._request("GET", f"/runs/{run_id}").json()

    def get_issues(self, run_id: str) -> dict:
        """GET /runs/{run_id}/issues — issues list as JSON."""
        return self._request(
            "GET", f"/runs/{run_id}/issues",
        ).json()

    def download_issues_csv(self, run_id: str) -> str:
        """GET /runs/{run_id}/issues.csv — Stage 47 CSV download as
        a plain string (caller writes to disk or pipes to pandas)."""
        return self._request(
            "GET", f"/runs/{run_id}/issues.csv",
        ).text

    def download_decisions_csv(self, run_id: str) -> str:
        """GET /runs/{run_id}/decisions.csv — Stage 48. Decisions
        snapshot merged with triage state (status/owner/notes) in
        one wide row per decision. Returns CSV text."""
        return self._request(
            "GET", f"/runs/{run_id}/decisions.csv",
        ).text

    def download_runs_csv(self, *,
                            entity_type: Optional[str] = None,
                            since: Optional[str] = None) -> str:
        """GET /tenants/{tid}/runs.csv — Stage 50. Compliance
        ""all runs in Q1"" pull. Same filters as list_runs JSON
        (entity_type narrowing, since cutoff). Returns CSV text."""
        params: Dict[str, Any] = {}
        if entity_type is not None:
            params["entity_type"] = entity_type
        if since is not None:
            params["since"] = since
        return self._request(
            "GET", f"/tenants/{self.tenant_id}/runs.csv",
            params=params or None,
        ).text

    def get_overrides(self) -> dict:
        """GET /tenants/{tid}/overrides — Stage 59. Returns the
        customer's current threshold + weights overrides."""
        return self._request(
            "GET", f"/tenants/{self.tenant_id}/overrides",
        ).json()

    def preview_run(self, entity_type: str) -> dict:
        """GET /tenants/{tid}/runs/preview — Stage 45. Dry-run
        analysis, no DB writes. Returns top issues + counts."""
        return self._request(
            "GET", f"/tenants/{self.tenant_id}/runs/preview",
            params={"entity_type": entity_type},
        ).json()

    def download_backfill_csv(self, entity_type: str, *,
                                 from_day: Optional[str] = None,
                                 until_day: Optional[str] = None,
                                 step_days: int = 1) -> str:
        """GET /tenants/{tid}/backfill.csv — Stage 67. Returns plain
        CSV text so the caller can write to disk or feed pandas. The
        chart-friendly wide layout matches the HTTP route exactly."""
        params: Dict[str, Any] = {
            "entity_type": entity_type, "step_days": step_days,
        }
        if from_day is not None:
            params["from"] = from_day
        if until_day is not None:
            params["until"] = until_day
        return self._request(
            "GET", f"/tenants/{self.tenant_id}/backfill.csv",
            params=params,
        ).text

    def backfill(self, entity_type: str, *,
                  from_day: Optional[str] = None,
                  until_day: Optional[str] = None,
                  step_days: int = 1) -> dict:
        """GET /tenants/{tid}/backfill — Stage 66. Point-in-time
        historical analysis over a date range. Read-only, no DB
        writes. Customer dashboard widget pattern: "show me how
        we looked over Q1"."""
        params: Dict[str, Any] = {
            "entity_type": entity_type,
            "step_days": step_days,
        }
        # the route accepts `from`/`until` (Python keywords elsewhere,
        # but valid query-string keys); httpx will encode them safely
        if from_day is not None:
            params["from"] = from_day
        if until_day is not None:
            params["until"] = until_day
        return self._request(
            "GET", f"/tenants/{self.tenant_id}/backfill",
            params=params,
        ).json()

    # --- write surface (operator role, Stage 63) -------------------

    def ingest_observations(self, entity_type: str,
                              observations: list) -> dict:
        """POST /tenants/{tid}/observations — push observations to
        the buffer (Stage 7d). Idempotent on (entity_id, day) per
        (tenant, entity_type) — re-pushing the same day overwrites.
        Requires operator-role tenant key."""
        return self._request(
            "POST", f"/tenants/{self.tenant_id}/observations",
            json={"entity_type": entity_type,
                  "observations": observations},
        ).json()

    def register_calibration(self, vertical: str, entity_type: str,
                               observations: list) -> dict:
        """POST /tenants/{tid}/calibrations — derive + persist a
        calibration from the passed observations. Requires
        operator-role tenant key.

        For "calibrate from stored observations", use the admin
        endpoint via an AdminClient (future Stage) — there's
        deliberately no shortcut on the customer SDK; recalibration
        is operationally significant and should go through ops."""
        return self._request(
            "POST", f"/tenants/{self.tenant_id}/calibrations",
            json={"vertical": vertical, "entity_type": entity_type,
                  "observations": observations},
        ).json()

    def create_schedule(self, *, vertical: str, entity_type: str,
                          connector_type: str,
                          connector_config: Optional[dict] = None,
                          frequency: str = "daily",
                          enabled: bool = True) -> dict:
        """POST /tenants/{tid}/schedules — register a new scheduled
        ingestion (Stage 39). Customer can self-serve onboard their
        connector. Requires operator-role tenant key."""
        body: Dict[str, Any] = {
            "vertical": vertical,
            "entity_type": entity_type,
            "connector_type": connector_type,
            "frequency": frequency,
            "enabled": enabled,
        }
        if connector_config is not None:
            body["connector_config"] = connector_config
        return self._request(
            "POST", f"/tenants/{self.tenant_id}/schedules",
            json=body,
        ).json()

    def enable_schedule(self, schedule_id: str) -> dict:
        """POST /schedules/{sid}/enable — toggle a paused schedule
        back on. Requires operator-role tenant key (the route
        checks that the schedule's tenant matches the caller)."""
        return self._request(
            "POST", f"/schedules/{schedule_id}/enable",
        ).json()

    def disable_schedule(self, schedule_id: str) -> dict:
        """POST /schedules/{sid}/disable — pause a schedule without
        deleting it. Useful for testing windows or holidays."""
        return self._request(
            "POST", f"/schedules/{schedule_id}/disable",
        ).json()

    # --- webhooks (Stage 73) -----------------------------------------

    def list_webhooks(self, *, enabled_only: bool = False) -> dict:
        """GET /tenants/{tid}/webhooks — Stage 73. secret_hash and
        secret_raw are NOT in the response (stripped server-side)."""
        params: Dict[str, Any] = {}
        if enabled_only:
            params["enabled_only"] = enabled_only
        return self._request(
            "GET", f"/tenants/{self.tenant_id}/webhooks",
            params=params or None,
        ).json()

    def create_webhook(self, url: str, *,
                        secret: Optional[str] = None) -> dict:
        """POST /tenants/{tid}/webhooks — register a webhook. The
        raw secret (if passed) comes back in the response ONCE and
        is never retrievable again; the caller wires it into their
        receiver's signature verification."""
        body: Dict[str, Any] = {"url": url}
        if secret is not None:
            body["secret"] = secret
        return self._request(
            "POST", f"/tenants/{self.tenant_id}/webhooks",
            json=body,
        ).json()

    def get_webhook(self, webhook_id: str) -> dict:
        """GET /webhooks/{wid} — Stage 73."""
        return self._request(
            "GET", f"/webhooks/{webhook_id}",
        ).json()

    def enable_webhook(self, webhook_id: str) -> dict:
        """POST /webhooks/{wid}/enable — Stage 73."""
        return self._request(
            "POST", f"/webhooks/{webhook_id}/enable",
        ).json()

    def disable_webhook(self, webhook_id: str) -> dict:
        """POST /webhooks/{wid}/disable — Stage 73. Soft-pause:
        row preserved, no future deliveries."""
        return self._request(
            "POST", f"/webhooks/{webhook_id}/disable",
        ).json()

    def delete_webhook(self, webhook_id: str) -> dict:
        """DELETE /webhooks/{wid} — Stage 73. Idempotent: returns
        deleted=false on a row that doesn't exist, no error."""
        return self._request(
            "DELETE", f"/webhooks/{webhook_id}",
        ).json()

    def test_webhook(self, webhook_id: str) -> dict:
        """POST /webhooks/{wid}/test — Stage 74. Sends a synthetic
        ping payload (event=ping) to the registered URL so the
        customer can verify their receiver works. Returns the
        delivery result dict (ok / status_code / error)."""
        return self._request(
            "POST", f"/webhooks/{webhook_id}/test",
        ).json()