"""Evaluation threshold reports for deterministic scenario fixtures."""

from __future__ import annotations

import json
from datetime import datetime, timezone
from pathlib import Path
from typing import Any

from .adapters import InMemorySemanticIndex
from .contracts import graph_from_markitect
from .models import Diagnostic, MemoryPath
from .retrieval import activation_quality_report, select_event_path
from .runtime import PhaseMemoryRuntime
from .utils import stable_digest, utc_now_iso

EVALUATION_REPORT_SCHEMA = "phase_memory.evaluation.threshold_report.v1"
EVALUATION_TREND_SCHEMA = "phase_memory.evaluation.trend_artifact.v1"
EVALUATION_TREND_HISTORY_SCHEMA = "phase_memory.evaluation.trend_history.v1"
EVALUATION_TREND_REGRESSION_GATE_SCHEMA = "phase_memory.evaluation.trend_regression_gate.v1"

DEFAULT_THRESHOLDS = {
    "policy_denial_count": 1,
    "lifecycle_action_count": 3,
    "path_event_count": 1,
    "semantic_hit_count": 1,
    "budget_omission_count": 1,
    "source_span_coverage": 1.0,
    "explanation_coverage": 1.0,
}


def evaluation_threshold_report(data: dict[str, Any], *, thresholds: dict[str, float] | None = None) -> dict[str, Any]:
    thresholds = {**DEFAULT_THRESHOLDS, **dict(thresholds or {})}
    scenarios = list(data.get("scenarios") or ())
    metrics = {
        "scenario_count": len(scenarios),
        "policy_denial_count": 0,
        "lifecycle_action_count": 0,
        "path_event_count": 0,
        "semantic_hit_count": 0,
        "budget_omission_count": 0,
        "source_span_coverage": 0.0,
        "explanation_coverage": 0.0,
    }
    scenario_reports: list[dict[str, Any]] = []

    for scenario in scenarios:
        scenario_id = str(scenario.get("id") or "")
        if scenario_id == "policy-denied-activation":
            report = _policy_scenario(scenario)
        elif scenario_id == "profile-lifecycle-rules":
            report = _lifecycle_scenario(scenario)
        elif scenario_id == "budget-path-and-semantic-hints":
            report = _budget_scenario(scenario)
        else:
            report = {"id": scenario_id, "metrics": {}, "diagnostics": [{"severity": "warn", "code": "unknown_scenario", "message": "Scenario is not recognized by this report."}]}
        scenario_reports.append(report)
        for key, value in report.get("metrics", {}).items():
            if key in metrics and isinstance(value, (int, float)):
                metrics[key] += value

    diagnostics = _threshold_diagnostics(metrics, thresholds)
    return {
        "schema_version": EVALUATION_REPORT_SCHEMA,
        "valid": not diagnostics,
        "metrics": metrics,
        "thresholds": thresholds,
        "scenarios": scenario_reports,
        "diagnostics": [diagnostic.to_dict() for diagnostic in diagnostics],
    }


def evaluation_trend_artifact(
    report: dict[str, Any],
    *,
    previous_report: dict[str, Any] | None = None,
    run_metadata: dict[str, Any] | None = None,
) -> dict[str, Any]:
    run_metadata = {
        "created_at": utc_now_iso(),
        **dict(run_metadata or {}),
    }
    metrics = dict(report.get("metrics") or {})
    thresholds = dict(report.get("thresholds") or {})
    previous_metrics = dict((previous_report or {}).get("metrics") or {})
    threshold_deltas = {
        key: round(float(metrics.get(key) or 0) - float(threshold), 4)
        for key, threshold in sorted(thresholds.items())
    }
    metric_deltas = {
        key: round(float(value or 0) - float(previous_metrics.get(key) or 0), 4)
        for key, value in sorted(metrics.items())
        if key in previous_metrics
    }
    diagnostics = [dict(item) for item in report.get("diagnostics", ())]
    for key, delta in metric_deltas.items():
        if delta < 0:
            diagnostics.append(
                Diagnostic(
                    "warn",
                    "evaluation_metric_regressed",
                    "Evaluation metric declined from the previous report.",
                    key,
                    {"delta": delta, "current": metrics.get(key), "previous": previous_metrics.get(key)},
                ).to_dict()
            )
    artifact_id = f"evaluation-trend:{stable_digest([run_metadata, metrics, thresholds, previous_metrics])}"
    return {
        "schema_version": EVALUATION_TREND_SCHEMA,
        "id": artifact_id,
        "valid": not any(item.get("severity") == "error" for item in diagnostics),
        "run": run_metadata,
        "metrics": metrics,
        "thresholds": thresholds,
        "threshold_deltas": threshold_deltas,
        "metric_deltas": metric_deltas,
        "report": report,
        "previous_report_id": (previous_report or {}).get("id", ""),
        "diagnostics": diagnostics,
    }


def evaluation_trend_history(artifacts: list[dict[str, Any]] | tuple[dict[str, Any], ...]) -> dict[str, Any]:
    ordered = sorted(
        (dict(artifact) for artifact in artifacts),
        key=lambda artifact: (
            str((artifact.get("run") or {}).get("created_at") or ""),
            str((artifact.get("run") or {}).get("run_id") or ""),
            str(artifact.get("id") or ""),
        ),
    )
    metric_keys = sorted({str(key) for artifact in ordered for key in (artifact.get("metrics") or {})})
    diagnostics = [
        Diagnostic(
            "error",
            "evaluation_trend_history_invalid_artifact",
            "Trend history can only contain evaluation trend artifacts.",
            f"artifacts.{index}.schema_version",
            {"artifact_id": artifact.get("id", "")},
        ).to_dict()
        for index, artifact in enumerate(ordered)
        if artifact.get("schema_version") != EVALUATION_TREND_SCHEMA
    ]
    return {
        "schema_version": EVALUATION_TREND_HISTORY_SCHEMA,
        "id": f"evaluation-trend-history:{stable_digest([artifact.get('id', '') for artifact in ordered])}",
        "valid": not diagnostics,
        "count": len(ordered),
        "metric_keys": metric_keys,
        "latest_artifact_id": ordered[-1].get("id", "") if ordered else "",
        "artifacts": ordered,
        "diagnostics": diagnostics,
    }


def load_evaluation_trend_history(path: str | Path) -> dict[str, Any]:
    path = Path(path)
    if not path.exists():
        return evaluation_trend_history(())
    data = json.loads(path.read_text(encoding="utf-8"))
    if data.get("schema_version") == EVALUATION_TREND_HISTORY_SCHEMA:
        return data
    if data.get("schema_version") == EVALUATION_TREND_SCHEMA:
        return evaluation_trend_history((data,))
    return evaluation_trend_history((data,))


def evaluation_trend_regression_gate(
    history: dict[str, Any],
    *,
    min_artifacts: int = 1,
) -> dict[str, Any]:
    artifacts = list(history.get("artifacts") or ())
    diagnostics: list[dict[str, Any]] = []
    if history.get("schema_version") != EVALUATION_TREND_HISTORY_SCHEMA:
        diagnostics.append(
            Diagnostic(
                "error",
                "evaluation_trend_history_invalid",
                "Regression gate requires a valid evaluation trend history artifact.",
                "schema_version",
                {"expected": EVALUATION_TREND_HISTORY_SCHEMA},
            ).to_dict()
        )
    if len(artifacts) < min_artifacts:
        diagnostics.append(
            Diagnostic(
                "warn",
                "evaluation_trend_history_insufficient",
                "Regression gate needs at least one persisted trend artifact.",
                "count",
                {"actual": len(artifacts), "minimum": min_artifacts},
            ).to_dict()
        )
    latest = artifacts[-1] if artifacts else {}
    previous = artifacts[-2] if len(artifacts) > 1 else {}
    latest_metrics = dict(latest.get("metrics") or {})
    previous_metrics = dict(previous.get("metrics") or {})
    regressions = {
        key: round(float(latest_metrics.get(key) or 0) - float(previous_metrics.get(key) or 0), 4)
        for key in sorted(set(latest_metrics) & set(previous_metrics))
        if float(latest_metrics.get(key) or 0) < float(previous_metrics.get(key) or 0)
    }
    for key, delta in regressions.items():
        diagnostics.append(
            Diagnostic(
                "warn",
                "evaluation_metric_regressed",
                "Evaluation metric declined from the previous trend artifact.",
                key,
                {
                    "delta": delta,
                    "current": latest_metrics.get(key),
                    "previous": previous_metrics.get(key),
                },
            ).to_dict()
        )
    for diagnostic in latest.get("diagnostics", ()):
        if isinstance(diagnostic, dict) and diagnostic.get("code") == "evaluation_metric_regressed":
            diagnostics.append(dict(diagnostic))
    threshold_failures = [
        dict(item)
        for item in (latest.get("report") or {}).get("diagnostics", ())
        if isinstance(item, dict) and item.get("code") == "evaluation_threshold_failed"
    ]
    for failure in threshold_failures:
        diagnostics.append(failure)
    return {
        "schema_version": EVALUATION_TREND_REGRESSION_GATE_SCHEMA,
        "id": f"evaluation-trend-regression-gate:{stable_digest([history.get('id', ''), latest.get('id', ''), regressions])}",
        "valid": not any(item.get("severity") == "error" for item in diagnostics)
        and not threshold_failures
        and not regressions,
        "artifact_count": len(artifacts),
        "latest_artifact_id": latest.get("id", ""),
        "previous_artifact_id": previous.get("id", ""),
        "metric_regressions": regressions,
        "threshold_failures": threshold_failures,
        "operator_guidance": {
            "compare": "Diff the latest evaluation-trend-history.json artifact metrics against the previous run id.",
            "gate": "Block promotion when metric_regressions or threshold_failures are non-empty.",
            "history_path": "reports/evaluation-trend-history.json",
        },
        "diagnostics": diagnostics,
    }


def write_evaluation_trend_history(path: str | Path, artifact: dict[str, Any]) -> dict[str, Any]:
    path = Path(path)
    existing = load_evaluation_trend_history(path)
    artifacts = list(existing.get("artifacts") or ())
    artifact_id = str(artifact.get("id") or "")
    if artifact_id and not any(str(item.get("id") or "") == artifact_id for item in artifacts):
        artifacts.append(dict(artifact))
    elif not artifact_id:
        artifacts.append(dict(artifact))
    history = evaluation_trend_history(tuple(artifacts))
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(json.dumps(history, indent=2, sort_keys=True) + "\n", encoding="utf-8")
    return history


def _policy_scenario(scenario: dict[str, Any]) -> dict[str, Any]:
    runtime = PhaseMemoryRuntime()
    response = runtime.plan_activation(
        scenario["graph"],
        max_items=int(scenario["profile"].get("activation", {}).get("max_items") or 4),
        max_tokens=int(scenario["profile"].get("activation", {}).get("max_tokens") or 60),
        profile_id=scenario["profile"]["id"],
        policy_context={"denied_labels": ["restricted"], "secrets_allowed": False, "trust_zone": "local"},
    )
    denials = response["data"]["policy_denials"]
    return {
        "id": scenario["id"],
        "metrics": {"policy_denial_count": len(denials)},
        "diagnostics": response["diagnostics"],
    }


def _lifecycle_scenario(scenario: dict[str, Any]) -> dict[str, Any]:
    runtime = PhaseMemoryRuntime()
    response = runtime.plan_lifecycle_with_profile(
        scenario["profile"],
        scenario["graph"],
        refresh_digests={"life.decision": "decision-new"},
        now=datetime(2026, 5, 18, tzinfo=timezone.utc),
    )
    return {
        "id": scenario["id"],
        "metrics": {"lifecycle_action_count": len(response["data"]["dry_run_actions"])},
        "diagnostics": response["diagnostics"],
    }


def _budget_scenario(scenario: dict[str, Any]) -> dict[str, Any]:
    runtime = PhaseMemoryRuntime()
    graph = graph_from_markitect(scenario["graph"]).value
    activation = runtime.plan_activation(
        scenario["graph"],
        max_items=int(scenario["profile"]["activation"]["max_items"]),
        max_tokens=int(scenario["profile"]["activation"]["max_tokens"]),
        profile_id=scenario["profile"]["id"],
        priority_node_ids=tuple(scenario["expect"]["selected_node_ids"]),
    )
    plan = activation["data"]["activation_plan"]
    quality = activation_quality_report(_activation_plan_from_response(activation), expected_node_ids=tuple(scenario["expect"]["selected_node_ids"]))
    path_events = select_event_path(graph.events, MemoryPath.from_mapping(scenario["path"]), max_events=2)
    index = InMemorySemanticIndex()
    index.upsert_nodes(list(graph.nodes))
    semantic_hits = index.query(graph_id=graph.graph_id, query="semantic restart", limit=2)
    return {
        "id": scenario["id"],
        "metrics": {
            "path_event_count": len(path_events),
            "semantic_hit_count": 1 if semantic_hits and semantic_hits[0]["id"] == scenario["expect"]["semantic_top_id"] else 0,
            "budget_omission_count": len(plan["omitted"]),
            "source_span_coverage": quality["source_span_coverage"],
            "explanation_coverage": quality["explanation_coverage"],
        },
        "diagnostics": activation["diagnostics"],
    }


def _activation_plan_from_response(response: dict[str, Any]):
    from .models import ActivationPlan

    data = response["data"]["activation_plan"]
    return ActivationPlan(
        plan_id=data["plan_id"],
        graph_id=data["graph_id"],
        selected_node_ids=tuple(data["selected_node_ids"]),
        selected_event_ids=tuple(data["selected_event_ids"]),
        omitted=tuple(data["omitted"]),
        token_estimate=data["token_estimate"],
        max_items=data["max_items"],
        max_tokens=data["max_tokens"],
        selection=response["data"]["package_request"]["selection"],
        diagnostics=(),
    )


def _threshold_diagnostics(metrics: dict[str, Any], thresholds: dict[str, float]) -> tuple[Diagnostic, ...]:
    diagnostics: list[Diagnostic] = []
    for key, threshold in sorted(thresholds.items()):
        actual = float(metrics.get(key) or 0)
        if actual < float(threshold):
            diagnostics.append(
                Diagnostic(
                    "error",
                    "evaluation_threshold_failed",
                    "Evaluation metric did not meet its threshold.",
                    key,
                    {"actual": actual, "threshold": threshold},
                )
            )
    return tuple(diagnostics)