"""Blob source contracts, retained binding evidence and bounded read-only monitoring."""
from __future__ import annotations

import copy
import json
import math
import re
import time
from datetime import datetime, timezone
from email.utils import parsedate_to_datetime
from pathlib import Path
from typing import Any, Callable
from urllib.parse import urlencode

try:
    from ._progress import Progress, reporting
    from . import blob_inventory, search_reconcile, _embedding, _search_read
    from ._common import (
        SEARCH_AUDIENCE, HelperFailure, TokenProvider, Transport, digest, load_approved_input,
        reject_secrets, require_allowed_fields, model_definition,
    )
except ImportError:
    from _progress import Progress, reporting
    import blob_inventory
    import search_reconcile
    import _embedding
    import _search_read
    from _common import (
        SEARCH_AUDIENCE, HelperFailure, TokenProvider, Transport, digest, load_approved_input,
        reject_secrets, require_allowed_fields, model_definition,
    )


SNAPSHOT_WARNING = (
    "Before/after inventories detect observed drift, not an atomic Storage snapshot "
    "or a source lock. Scheduled sources can change after this run."
)


RETRY_STATUS = {408, 429, 500, 502, 503, 504}


def validate_content_understanding(value: Any, *, enabled: bool) -> dict[str, Any] | None:
    if not enabled:
        if value is not None:
            raise _failure("cu-choice-conflict", "Minimal extraction must omit Content Understanding choices.")
        return None
    if not isinstance(value, dict):
        raise _failure("cu-prerequisite-missing", "Standard extraction requires an existing CU-capable AIServices account.")
    require_allowed_fields(value, {"endpoint", "auth", "prerequisites"}, label="Content Understanding choices")
    endpoint = value.get("endpoint")
    if (
        not isinstance(endpoint, str)
        or re.fullmatch(r"https://[a-z0-9][a-z0-9-]{0,62}\.services\.ai\.azure\.com/?", endpoint) is None
        or value.get("auth") != "system-assigned"
    ):
        raise _failure("cu-auth-unsupported", "Select an exact AIServices services.ai.azure.com endpoint and existing Search system-assigned identity; no keys.")
    prerequisites = value.get("prerequisites")
    if not isinstance(prerequisites, dict):
        raise _failure("cu-prerequisite-missing", "Supply current CU resource, configuration, identity and network evidence references.")
    fields = {"resource", "configuration", "identity", "network"}
    require_allowed_fields(prerequisites, fields, label="Content Understanding prerequisites")
    if any(not isinstance(prerequisites.get(key), str) or not prerequisites[key].strip()
           or len(prerequisites[key]) > 4096 for key in fields):
        raise _failure("cu-prerequisite-missing", "Owner-verified CU capability/region, configuration, Search role and reachability evidence is required.")
    return copy.deepcopy(value)


def verify_content_understanding_readback(choice: dict[str, Any] | None, current: Any) -> None:
    if choice is None or current is None:
        return
    parameters = current.get("azureBlobParameters") if isinstance(current, dict) else None
    ingestion = parameters.get("ingestionParameters") if isinstance(parameters, dict) else None
    ai = ingestion.get("aiServices") if isinstance(ingestion, dict) else None
    if (
        not isinstance(ai, dict) or ingestion.get("contentExtractionMode") != "standard"
        or not isinstance(ai.get("uri"), str)
        or ai["uri"].rstrip("/") != choice["endpoint"].rstrip("/")
    ):
        raise _failure("cu-readback-mismatch", "Observed standard extraction and CU endpoint must match the selected configuration.")
    key = ai.get("apiKey")
    if (key is not None and not (isinstance(key, str) and key == "")
            or ingestion.get("identity") is not None):
        raise _failure("cu-auth-conflict", "Observed CU authentication does not prove system-assigned mode; credential details withheld.")


def generated_resources(current: dict[str, Any], *, strict: bool = False) -> list[dict[str, Any]]:
    parameters = current.get("azureBlobParameters")
    created = parameters.get("createdResources") if isinstance(parameters, dict) else None
    generated = []
    if isinstance(created, dict):
        for kind, name in created.items():
            if (
                kind in {"datasource", "dataSourceConnection", "indexer", "skillset", "index"}
                and isinstance(name, str) and re.fullmatch(r"[a-zA-Z0-9][a-zA-Z0-9_-]{0,127}", name)
            ):
                generated.append({
                    "type": "datasource" if kind == "dataSourceConnection" else kind,
                    "name": name, "service_managed": True,
                })
    generated.sort(key=lambda item: (item["type"], item["name"]))
    if strict and (
        not isinstance(created, dict) or len(created) != 4 or len(generated) != 4
        or {item["type"] for item in generated} != {"datasource", "indexer", "skillset", "index"}
    ):
        raise _failure("generated-resources-unverified", "Exact service-generated identities are required for reuse.")
    return generated


def _read_intent(path: Path) -> dict[str, Any]:
    try:
        document = json.loads(path.read_text(encoding="utf-8"))
    except (OSError, UnicodeError, json.JSONDecodeError) as exc:
        raise _failure("input-unreadable", "Input must be readable UTF-8 JSON.") from exc
    if not isinstance(document, dict):
        raise _failure("input-schema-invalid", "Input must be an object.")
    return document


def _receipt_paths(request: dict[str, Any]) -> tuple[str, str] | None:
    paths = [request.get(field) for field in ("reuse_input_file", "reuse_result_file")]
    if paths == [None, None]:
        return None
    if not all(isinstance(path, str) and path.strip() for path in paths):
        raise _failure("reuse-evidence-invalid", "Select both retained approved input and creation result files.")
    return paths[0], paths[1]


def _reuse_receipts(paths: tuple[str, str] | None) -> tuple[dict[str, Any], dict[str, Any]] | None:
    if paths is None:
        return None
    try:
        _, prior, fingerprint = load_approved_input(Path(paths[0]))
    except UnicodeError as exc:
        raise _failure("input-unreadable", "Retained input must be readable UTF-8 JSON.") from exc
    _validate_plan(prior)
    result = _read_intent(Path(paths[1]))
    _validate_reuse_receipts(prior, fingerprint, result)
    return prior, result


def _validate_reuse_receipts(prior, fingerprint, result):
    reject_secrets(result)
    if not all(isinstance(result.get(field), dict) for field in (
        "approved_plan", "source_evidence", "resources", "verification", "source"
    )):
        raise _failure("reuse-evidence-invalid", "Retained creation result sections must be objects.")
    if (
        prior["source"]["action"] != "create" or result.get("status") != "completed"
        or result["approved_plan"].get("confirmed") is not True
        or result.get("approved_plan") != {"confirmed": True, "fingerprint": fingerprint}
        or result.get("source_evidence", {}).get("boundary") != prior["boundary"]
        or result.get("source_evidence", {}).get("inventory_digest") != prior["inventory_digest"]
    ):
        raise _failure("reuse-evidence-invalid", "Retained records must prove the exact approved source creation.")


def _connection_binding(connection, boundary):
    if connection is None or isinstance(connection, str) and connection.lower() in ("", "<redacted>"):
        return "concealed"
    if isinstance(connection, str) and connection.startswith("ResourceId="):
        if connection.removesuffix(";") != f"ResourceId={boundary['storage_id']}":
            raise _failure("boundary-mismatch", "Observed connection targets a different Storage account.")
        return "visible"
    raise _failure("source-binding-conflict", "Observed credentials are not the selected keyless binding or a recognized concealed value; details withheld.")


def _verify_storage_binding(
    source: dict[str, Any], boundary: dict[str, Any], current: dict[str, Any],
    generated: list[dict[str, Any]],
    load_receipts: Callable[[], tuple[dict[str, Any], dict[str, Any]] | None],
) -> None:
    connection = current["azureBlobParameters"].get("connectionString")
    if _connection_binding(connection, boundary) == "visible":
        return
    receipts = load_receipts()
    if receipts is None:
        raise _failure(
            "source-binding-unverified",
            "Source account binding is unknown: GET the exact source definition or select its retained approved input/successful creation result pair. Redaction is not a mismatch; snippets are not binding proof.",
        )
    _verify_creation_binding(source, boundary, current, generated, receipts)


def _verify_creation_binding(
    source: dict[str, Any], boundary: dict[str, Any], current: dict[str, Any],
    generated: list[dict[str, Any]], receipts: tuple[dict[str, Any], dict[str, Any]],
) -> None:
    prior, result = receipts
    observed = {
        "type": "knowledge-source", "name": source["name"], "etag": current["@odata.etag"],
        "definition_digest": digest(_search_read._definition(current)),
    }
    if (
        prior["boundary"] != boundary
        or any(prior["source"].get(field) != source[field] for field in ("endpoint", "name", "api_version"))
        or not _search_read.definitions_match(prior["source"]["desired"], current)
        or result.get("resources", {}).get("created") != [observed]
        or result.get("verification", {}).get("readback") != observed
        or result.get("source", {}).get("generated") != generated
    ):
        raise _failure("source-binding-unverified", "Retained creation evidence does not match the fresh source identity/ETag.")


def _failure(code: str, message: str, *, request_id: str | None = None) -> HelperFailure:
    return HelperFailure(code, message, blocked_at="verification", request_id=request_id)


def _timestamp(value: Any) -> datetime:
    if not isinstance(value, str):
        raise _failure("ingestion-status-invalid", "Synchronization timestamp is missing.")
    try:
        parsed = datetime.fromisoformat(value.replace("Z", "+00:00"))
    except ValueError as exc:
        raise _failure("ingestion-status-invalid", "Synchronization timestamp is invalid.") from exc
    if parsed.tzinfo is None:
        raise _failure("ingestion-status-invalid", "Synchronization timestamp needs a time zone.")
    return parsed


def _poll_limits(value: Any) -> dict[str, int]:
    if not isinstance(value, dict):
        raise _failure("input-schema-invalid", "poll must be an object.")
    require_allowed_fields(
        value, {"deadline_seconds", "max_requests", "interval_seconds"}, label="poll"
    )
    for field, maximum in (
        ("deadline_seconds", 3600), ("max_requests", 1000), ("interval_seconds", 60)
    ):
        if type(value.get(field)) is not int or not 1 <= value[field] <= maximum:
            raise _failure("input-schema-invalid", "Polling limits must be bounded positive integers.")
    return value


def _validate_plan(plan: dict[str, Any]) -> tuple[dict[str, Any], dict[str, Any]]:
    reject_secrets(plan)
    require_allowed_fields(
        plan,
        {"operation", "owner", "cleanup_approved", "source", "boundary", "inventory_digest",
         "inventory_limits", "poll", "expected_generated", "expected_source_absent", "embedding",
         "content_understanding", "cu_plan_version"},
        label="Blob source plan",
    )
    if plan.get("operation") != "reconcile-and-monitor" or plan.get("cleanup_approved") is not False:
        raise _failure("operation-invalid", "Blob application requires reconcile-and-monitor without cleanup.")
    source = plan.get("source")
    if not isinstance(source, dict) or not isinstance(plan.get("owner"), str) or not plan["owner"]:
        raise _failure("input-schema-invalid", "A source plan and owner are required.")
    if (
        source.get("operation") != "reconcile"
        or source.get("resource_type") != "knowledge-source"
        or source.get("action") not in ("create", "reuse")
        or not isinstance(source.get("api_version"), str)
        or source.get("owner") != plan["owner"]
        or not isinstance(source.get("desired"), dict)
        or source["desired"].get("kind") != "azureBlob"
        or source.get("ai_services_api_key_environment") is not None
        or source.get("ai_services_key_acquisition") is not None
    ):
        raise _failure("step-contract-mismatch", "Only same-owner Blob creation or exact reuse is supported.")
    search_reconcile._validate_plan(source)
    _search_read._resource_url(source)
    boundary = blob_inventory.validate_boundary(plan.get("boundary"))
    blob_inventory.validate_limits(plan.get("inventory_limits"))
    _poll_limits(plan.get("poll"))
    if "expected_source_absent" in plan and (
        plan["expected_source_absent"] is not True or source["action"] != "create"
        or source.get("expected_etag") is not None
    ):
        raise _failure("step-contract-mismatch", "Expected absence is only valid for a creation plan.")
    if "expected_generated" in plan and (
        source["action"] != "reuse"
        or not isinstance(plan["expected_generated"], list)
        or len(plan["expected_generated"]) != 4
        or any(not isinstance(item, dict) or set(item) != {"type", "name", "service_managed"}
               or item["service_managed"] is not True
               or not isinstance(item["type"], str)
               or not isinstance(item["name"], str)
               or re.fullmatch(r"[a-zA-Z0-9][a-zA-Z0-9_-]{0,127}", item["name"]) is None
               for item in plan["expected_generated"])
        or {item["type"] for item in plan["expected_generated"]} != {"datasource", "indexer", "skillset", "index"}
    ):
        raise _failure("generated-resources-unverified", "Expected generated identities require a complete reuse plan.")
    parameters = source["desired"]["azureBlobParameters"]
    if (
        parameters["connectionString"].removesuffix(";") != f"ResourceId={boundary['storage_id']}"
        or parameters["containerName"] != boundary["container"]
        or parameters["folderPath"] != (boundary["prefix"] or None)
        or parameters["isADLSGen2"] != boundary["is_adls"]
        or "createdResources" in parameters
        or source["source_evidence"]["inventory_digest"] != plan.get("inventory_digest")
    ):
        raise _failure("boundary-mismatch", "Source definition must bind the exact discovered boundary and inventory.")
    if (
        not isinstance(plan.get("inventory_digest"), str)
        or _search_read.SHA256.fullmatch(plan["inventory_digest"]) is None
    ):
        raise _failure("source-evidence-invalid", "The approved inventory digest is required.")
    ingestion = parameters.get("ingestionParameters")
    if not isinstance(ingestion, dict) or ingestion.get("assetStore") is not None:
        raise _failure(
            "source-write-forbidden",
            "Ingestion parameters are required; asset-store writes are outside this read-only-source workflow.",
        )
    _embedding.validate_plan_choice(plan)
    standard = ingestion.get("contentExtractionMode") == "standard"
    if "cu_plan_version" in plan and (plan["cu_plan_version"] != "1.0" or not standard):
        raise _failure("cu-plan-version-invalid", "CU planner artifacts require version 1.0 and standard extraction.")
    # Absence/generated guards predate CU planning and remain valid on legacy
    # wire-only artifacts. Only CU-specific provenance selects the new contract.
    planner_cu = standard and any(field in plan for field in (
        "cu_plan_version", "embedding", "content_understanding",
    ))
    cu = validate_content_understanding(
        plan.get("content_understanding"), enabled=planner_cu,
    )
    if cu is not None:
        expected = {
            "contentExtractionMode": "standard", "disableImageVerbalization": True,
            "identity": None, "ingestionSchedule": None,
            "aiServices": {"uri": cu["endpoint"].rstrip("/")},
        }
        if "embedding" in plan:
            expected["embeddingModel"] = model_definition(plan["embedding"])
        if source["api_version"].endswith("-preview"):
            expected.update(networkAccessMode="public", ingestionPermissionOptions=[])
        if ingestion != expected or boundary["is_adls"] and source["api_version"] != "2026-08-01-preview":
            raise _failure("cu-plan-mismatch", "Standard CU requires the unchanged keyless public definition, matching optional embeddings and no chat, asset store, permissions or schedule.")
    return source, boundary


def _first_error(state: dict[str, Any]) -> dict[str, Any] | None:
    errors = state.get("errors")
    if errors is None or errors == []:
        return None
    if not isinstance(errors, list) or any(not isinstance(error, dict) for error in errors):
        raise _failure("ingestion-status-invalid", "Ingestion errors have an invalid shape.")
    error = errors[0]
    # Document errors can contain content, SAS URLs, and credentials in free text.
    return {
        "status": error.get("statusCode") if type(error.get("statusCode")) is int else None,
        "message": "Document-level ingestion error; sensitive service text withheld.",
        "diagnostic_digest": digest(error),
    }


def _synchronization_state(state, request_id=None):
    if state is None:
        return None
    if not isinstance(state, dict):
        raise _failure("ingestion-status-invalid", "Synchronization state must be an object.", request_id=request_id)
    return dict(state)


def _retry_after(value, *, now=None):
    now = now or datetime.now(timezone.utc)
    kind = getattr(value, "kind", None)
    try:
        if kind is not None:
            if kind == "overlong":
                return math.inf
            payload = getattr(value, "value", None)
            if (not isinstance(kind, str) or kind not in {"seconds", "date", "date-rfc850"}
                    or type(payload) not in (int, float)
                    or (type(payload) is float and not math.isfinite(payload))):
                return None
            if kind == "seconds":
                return payload if payload >= 0 and payload == int(payload) else None
            parsed = datetime.fromtimestamp(payload, timezone.utc)
            obsolete_date = kind == "date-rfc850"
        else:
            if not isinstance(value, str) or len(value) > 128:
                return None
            if value.isascii() and value.isdigit() and len(value) <= 10:
                return int(value)
            parsed = parsedate_to_datetime(value)
            obsolete_date = bool(re.fullmatch(r"[A-Za-z]+, \d{2}-[A-Za-z]{3}-\d{2} \d{2}:\d{2}:\d{2} GMT", value))
        if obsolete_date:
            year = now.year // 100 * 100 + parsed.year % 100
            if year > now.year + 50:
                year -= 100
            parsed = parsed.replace(year=year)
        if parsed.tzinfo is not None:
            return max(0, (parsed - now).total_seconds())
    except (ValueError, OverflowError, TypeError, OSError):
        return None
    return None


def _execution_progress(body, not_before):
    if (not isinstance(body, dict) or not isinstance(body.get("status"), str)
            or body["status"] not in {"running", "error", "unknown"}):
        raise _failure("indexer-status-invalid", "Indexer status must be an object.")
    if body["status"] == "error":
        raise _failure("indexer-status-error", "Indexer availability reports an error; execution success is not inferred.")
    run = body.get("lastResult")
    if run is None:
        return None
    if not isinstance(run, dict):
        raise _failure("indexer-status-invalid", "Latest indexer execution must be an object.")
    start = _timestamp(run.get("startTime"))
    if start < not_before:
        return None
    status = run.get("status")
    if not isinstance(status, str) or status not in {"inProgress", "success", "transientFailure", "persistentFailure", "reset"}:
        raise _failure("indexer-status-invalid", "Unknown latest execution status; top-level running is not execution proof.")
    result = {"startTime": run["startTime"], "run_status": status}
    if run.get("endTime") is not None:
        if _timestamp(run["endTime"]) < start:
            raise _failure("indexer-status-invalid", "Indexer execution interval is invalid.")
        result["endTime"] = run["endTime"]
    for field, target in (("itemsProcessed", "items_attempted"), ("itemsFailed", "items_failed")):
        if field in run:
            if type(run[field]) is not int or run[field] < 0:
                raise _failure("indexer-status-invalid", "Indexer execution counters are invalid.")
            result[target] = run[field]
    if result.get("items_failed", 0) > result.get("items_attempted", result.get("items_failed", 0)):
        raise _failure("indexer-status-invalid", "Failed item count exceeds attempted items.")
    errors = run.get("errors", [])
    if errors is not None and (not isinstance(errors, list) or any(not isinstance(item, dict) for item in errors)):
        raise _failure("indexer-status-invalid", "Indexer execution errors are malformed.")
    result["error_count"] = len(errors or [])
    return result


def _execution_completed_by(execution, end, not_before):
    required = {"startTime", "endTime", "run_status", "error_count"}
    if (not isinstance(execution, dict) or not required <= execution.keys()
            or execution.keys() - required - {"items_attempted", "items_failed"}
            or execution["run_status"] != "success"
            or type(execution["error_count"]) is not int or execution["error_count"] != 0
            or any(type(execution[key]) is not int or execution[key] < 0
                   for key in ("items_attempted", "items_failed") if key in execution)
            or execution.get("items_failed", 0)):
        return False
    try:
        return not_before <= _timestamp(execution["startTime"]) <= _timestamp(execution["endTime"]) <= end
    except HelperFailure:
        return False


@reporting("blob-monitor")
def monitor(
    source: dict[str, Any],
    *,
    not_before: datetime,
    limits: dict[str, int],
    token_provider: TokenProvider,
    transport: Transport,
    require_new_cycle: bool = False,
    excluded_cycle: list[str] | None = None,
    monotonic: Callable[[], float] = time.monotonic,
    sleep: Callable[[float], None] = time.sleep,
    progress: Progress | None = None,
    cancelled: Callable[[], bool] = lambda: False,
    indexer_name: str | None = None,
) -> dict[str, Any]:
    _poll_limits(limits)
    progress.update("ingestion-cycle")
    excluded = tuple(_timestamp(value) for value in excluded_cycle) if excluded_cycle is not None else None
    url = (
        f"{source['endpoint'].rstrip('/')}/knowledgesources('{_search_read._odata_name(source['name'])}')/status?"
        + urlencode({"api-version": source["api_version"]})
    )
    token = token_provider(SEARCH_AUDIENCE)
    started = monotonic()
    deadline = started + limits["deadline_seconds"]
    request_ids: list[str] = []
    first_error: dict[str, Any] | None = None
    first_retry: dict[str, Any] | None = None
    observed = "no-completed-cycle"
    initial_cycle: tuple[Any, Any] | None = None
    first_response = True
    checks = 0
    delay = limits["interval_seconds"]
    latest = {}
    previous = None
    previous_execution = None
    execution_guard = None
    pause_reason = "request-limit"
    newest_run = None
    synchronization_status = "not-reported"

    def report(phase, next_check=None):
        value = {
            "schema_version": "1.0", "phase": phase,
            "run_start": _timestamp(latest["startTime"]).isoformat() if latest.get("startTime") else None,
            "processed": latest.get("itemsUpdatesProcessed"), "failed": latest.get("itemsUpdatesFailed"),
            "skipped": latest.get("itemsSkipped"), "unit": "item-updates",
            "total": None, "remaining": None, "denominator": "not-comparable-to-files",
            "synchronization_status": synchronization_status,
            "elapsed_seconds": max(0, monotonic() - started), "next_check_seconds": next_check,
        }
        progress.counts["status_checks"] = checks
        progress.blob_update(value)
        return value

    def failure_result(*args):
        result = _readiness_failure(*args)
        result["progress"] = report("failed")
        result["watch"] = {"schema_version": "1.0", "state": "blocked", "reason": "evidence-failure",
                           "elapsed_seconds": max(0, monotonic() - started),
                           "status_checks": checks, "latest": copy.deepcopy(latest)}
        return result

    def read_status(target):
        nonlocal checks, retry_after
        remaining = deadline - monotonic()
        if remaining <= 0:
            raise _failure("ingestion-watch-expired", "The client watch window elapsed before this read.")
        checks += 1
        response = transport(
            "GET", target, token, timeout=min(30, remaining),
            max_response_bytes=8 * 1024 * 1024, follow_redirects=False,
            response_deadline=monotonic() + min(30, remaining),
        )
        if response.request_id:
            request_ids.append(response.request_id)
        if response.status != 200:
            value = getattr(response, "retry_after", None)
            if value is None:
                value = next((v for k, v in response.headers.items() if k.lower() == "retry-after"), None)
            retry_after = _retry_after(value)
            raise HelperFailure("ingestion-inaccessible", "Status read is inaccessible.",
                                blocked_at="verification", status=response.status, request_id=response.request_id)
        return response

    while checks < limits["max_requests"]:
        remaining = deadline - monotonic()
        if cancelled():
            pause_reason = "cancelled"
            break
        if remaining <= 0:
            pause_reason = "deadline"
            break
        retry_after = None
        throttled = False
        try:
            response = read_status(url)
        except KeyboardInterrupt:
            pause_reason = "cancelled"
            break
        except HelperFailure as failure:
            if failure.request_id and failure.request_id not in request_ids:
                request_ids.append(failure.request_id)
            if failure.code == "response-deadline-exceeded":
                first_retry = first_retry or {"code": failure.code, "status": failure.http_status,
                                              "request_id": failure.request_id}
                if monotonic() >= deadline:
                    pause_reason = "deadline"
                    break
            if failure.code == "ingestion-watch-expired":
                pause_reason = "deadline"
                break
            if retry_after is None:
                retry_after = _retry_after(failure.retry_after)
            if (failure.http_status not in RETRY_STATUS
                    and failure.code not in {"azure-response-ambiguous", "response-deadline-exceeded"}):
                return failure_result("ingestion-inaccessible", failure.request_id, request_ids,
                                          first_error, first_retry, failure.http_status)
            if first_retry is None:
                first_retry = {"code": failure.code, "status": failure.http_status,
                               "request_id": failure.request_id}
            throttled = failure.http_status == 429
            delay = min(60, max(limits["interval_seconds"], delay * 2))
        else:
            if monotonic() >= deadline:
                pause_reason = "deadline"
                break
            body = response.body
            if not isinstance(body, dict) or body.get("kind") != "azureBlob":
                raise _failure("ingestion-status-invalid", "Expected azureBlob status.", request_id=response.request_id)
            synchronization_status = body.get("synchronizationStatus", "not-reported")
            if synchronization_status not in ("not-reported", "active", "creating", "deleting"):
                raise _failure("ingestion-status-invalid", "Unknown knowledge-source synchronization availability.",
                               request_id=response.request_id)
            current = _synchronization_state(body.get("currentSynchronizationState"), response.request_id)
            last = _synchronization_state(body.get("lastSynchronizationState"), response.request_id)
            for state in (current, last):
                if state is not None:
                    _timestamp(state.get("startTime"))
                    _first_error(state)
            state = current or last
            start = _timestamp(state["startTime"]) if state else None
            if start is not None and start >= not_before and (newest_run is None or start >= newest_run):
                newest_run = start
                error = _first_error(state)
                if first_error is None and error:
                    first_error = {**error, "request_id": response.request_id}
                latest = {"startTime": state["startTime"],
                          "state": "in-progress" if current else "completed-cycle-observed"}
                for field in ("itemsUpdatesProcessed", "itemsUpdatesFailed", "itemsSkipped"):
                    if field in state:
                        if type(state[field]) is not int or state[field] < 0:
                            raise _failure("ingestion-status-invalid", "Observed synchronization counters are invalid.",
                                           request_id=response.request_id)
                        latest[field] = state[field]
                if current:
                    observed = "in-progress"
                signature = digest(latest)
                delay = (limits["interval_seconds"] if signature != previous
                         else min(60, delay * 2))
                previous = signature
            else:
                latest = {}
                observed = "stale-success-or-unrelated-cycle" if state else "no-completed-cycle"
                signature = digest({})
                delay = limits["interval_seconds"] if signature != previous else min(60, delay * 2)
                previous = signature
            if execution_guard is not None:
                latest["indexer_execution"] = copy.deepcopy(execution_guard)
            if first_response and require_new_cycle and last:
                initial_cycle = (last.get("startTime"), last.get("endTime"))
            first_response = False
            if (
                last and last.get("endTime") is not None
                and _timestamp(last.get("startTime")) >= max(not_before, newest_run or not_before)
                and (last.get("startTime"), last.get("endTime")) != initial_cycle
                and (excluded is None or (_timestamp(last.get("startTime")), _timestamp(last.get("endTime"))) != excluded)
            ):
                status = last.get("status")
                if status is not None and not isinstance(status, str):
                    raise _failure("ingestion-status-invalid", "Synchronization status must be a string when present.")
                if status in {"failure", "partialSuccess"}:
                    return failure_result(f"ingestion-{status}", response.request_id,
                                              request_ids, first_error, first_retry)
                if status in {None, "success"}:
                    start = _timestamp(last.get("startTime"))
                    end = _timestamp(last.get("endTime"))
                    failed = last.get("itemsUpdatesFailed")
                    processed = last.get("itemsUpdatesProcessed")
                    skipped = last.get("itemsSkipped")
                    if end < start or any(type(count) is not int or count < 0 for count in (failed, processed, skipped)):
                        raise _failure("ingestion-status-invalid", "Completed synchronization counters or interval are invalid.")
                    if failed or first_error:
                        return failure_result("ingestion-partialSuccess", response.request_id,
                                                  request_ids, first_error, first_retry)
                    if (not current and synchronization_status in ("active", "not-reported")
                            and (execution_guard is None
                                 or _execution_completed_by(execution_guard, end, not_before))):
                        return {
                            "status": "verified",
                            "progress": report("completed"),
                            "synchronization": {
                                field: last[field] for field in
                                ("startTime", "endTime", "itemsUpdatesProcessed", "itemsUpdatesFailed", "itemsSkipped")
                            },
                            "not_before": not_before.isoformat(),
                            "request_ids": request_ids,
                            "first_retry": first_retry,
                            "watch": {"schema_version": "1.0", "state": "completed",
                                      "elapsed_seconds": max(0, monotonic() - started),
                                      "status_checks": checks, "latest": latest},
                        }
                else:
                    raise _failure("ingestion-status-invalid", "Unknown synchronization completion status.")
            elif last and not current:
                observed = "stale-success-or-unrelated-cycle"
            if indexer_name and checks < limits["max_requests"] and monotonic() < deadline and not cancelled():
                target = (f"{source['endpoint'].rstrip('/')}/indexers('{_search_read._odata_name(indexer_name)}')/status?"
                          + urlencode({"api-version": source["api_version"]}))
                run_response = None
                try:
                    run_response = read_status(target)
                    cutoff = max(not_before, newest_run or not_before)
                    if execution_guard is not None:
                        cutoff = min(cutoff, _timestamp(execution_guard["startTime"]))
                    execution = _execution_progress(run_response.body, cutoff)
                    if (execution is not None and execution_guard is not None
                            and _timestamp(execution["startTime"]) < _timestamp(execution_guard["startTime"])):
                        execution = None
                    if execution is not None:
                        if execution_guard is not None or execution["run_status"] == "inProgress":
                            execution_guard = copy.deepcopy(execution)
                        execution_signature = digest(execution)
                        if execution_signature != previous_execution:
                            delay = limits["interval_seconds"]
                        previous_execution = execution_signature
                        latest["indexer_execution"] = execution
                        if (execution.get("items_failed", 0) or execution["error_count"]
                                or execution["run_status"] in {"transientFailure", "persistentFailure"}):
                            first_error = first_error or {
                                "status": None, "message": "Latest relevant indexer execution reports failures; details withheld.",
                                "request_id": run_response.request_id,
                            }
                except KeyboardInterrupt:
                    pause_reason = "cancelled"
                    break
                except HelperFailure as failure:
                    if failure.request_id is None and run_response is not None:
                        failure.request_id = run_response.request_id
                    if failure.request_id and failure.request_id not in request_ids:
                        request_ids.append(failure.request_id)
                    if failure.code == "response-deadline-exceeded":
                        first_retry = first_retry or {"code": failure.code, "status": failure.http_status,
                                                      "request_id": failure.request_id}
                        if monotonic() >= deadline:
                            pause_reason = "deadline"
                            break
                    if failure.code == "ingestion-watch-expired":
                        pause_reason = "deadline"
                        break
                    if (failure.http_status not in RETRY_STATUS
                            and failure.code not in {"azure-response-ambiguous", "response-deadline-exceeded"}):
                        code = failure.code if failure.code in {"indexer-status-invalid", "indexer-status-error"} else "indexer-status-unverified"
                        return failure_result(code, failure.request_id, request_ids,
                                                  first_error, first_retry, failure.http_status)
                    first_retry = first_retry or {"code": failure.code, "status": failure.http_status,
                                                  "request_id": failure.request_id}
                    throttled = failure.http_status == 429
                    if retry_after is None:
                        retry_after = _retry_after(failure.retry_after)
                    delay = min(60, delay * 2)
        remaining = deadline - monotonic()
        if cancelled():
            pause_reason = "cancelled"
            break
        if retry_after is not None and retry_after > min(60, remaining):
            report("throttled" if throttled else "waiting")
            pause_reason = "retry-after"
            break
        if remaining > 0 and checks < limits["max_requests"]:
            try:
                wait = min(max(delay, retry_after or 0), remaining)
                report("throttled" if throttled else
                       "ingesting" if observed == "in-progress" else "waiting", wait)
                sleep(wait)
            except KeyboardInterrupt:
                pause_reason = "cancelled"
                break
        if monotonic() >= deadline:
            pause_reason = "deadline"
    result = _readiness_failure(
        "ingestion-timeout", request_ids[-1] if request_ids else None,
        request_ids, first_error, first_retry,
    )
    result["observed"] = observed
    result["watch"] = {"schema_version": "1.0", "state": "paused", "reason": pause_reason,
                       "elapsed_seconds": max(0, monotonic() - started),
                       "status_checks": checks, "latest": latest,
                       "service_execution": "not-modified"}
    if first_error or latest.get("itemsUpdatesFailed"):
        result["code"] = "ingestion-partialSuccess"
    result["progress"] = report("failed" if result["code"] == "ingestion-partialSuccess" else "paused")
    result["safe_next_decision"] = (
        "Service reports item failures; retain the partial work and inspect exact private error evidence read-only. "
        "A new watch does not repair failures; do not replay writes or default to cleanup."
    ) if result["code"] == "ingestion-partialSuccess" else (
        "Client watch paused; this is not an ingestion failure. Resume GET-only with the unchanged input "
        "and readiness receipt using blob_recheck.py --input <original-input> --receipt <checkpoint>. "
        "Do not recreate, run/reset, delete, or infer corpus completion."
    )
    return result


def _readiness_failure(
    code: str, request_id: str | None, request_ids: list[str],
    first_error: dict[str, Any] | None, first_retry: dict[str, Any] | None,
    status: int | None = None,
) -> dict[str, Any]:
    return {
        "status": "unverified", "code": code, "request_id": request_id,
        "http_status": status, "request_ids": request_ids,
        "first_error": first_error, "first_retry": first_retry,
    }