from __future__ import annotations

from datetime import datetime, timedelta, timezone
from typing import Any

from .progress import STEP_ALIASES, STEP_LABELS, STEP_ORDER
from .timeline_model import build_run_timeline_model
from .config import settings

PRODUCT_STEPS = [{"id": step, "label": STEP_LABELS[step]} for step in STEP_ORDER]


def _runs_prefix() -> str:
    return settings.bucket_runs_prefix.strip().strip("/") or "runs"

TERMINAL_GLOBAL_STATUSES = {"succeeded", "partial", "failed", "cancelled", "blocked", "waiting_manual_action"}
SUCCESS_RAW_STATUSES = {
    "success",
    "done",
    "completed",
    "passed",
    "full_inference_success",
    "repair_success",
}
PARTIAL_RAW_STATUSES = {
    "full_inference_candidate_health_passed",
    "health_only",
    "partial",
    "partial_validation",
    "completed_with_warnings",
}
MANUAL_RAW_STATUSES = {
    "manual_hardware_required",
    "generated_needs_manual_hardware",
    "waiting_manual_hardware",
    "manual_action_required",
}
FAILED_RAW_STATUSES = {"failed", "failure", "error", "repair_failed"}
CANCELLED_RAW_STATUSES = {"cancelled", "canceled"}
BLOCKED_RAW_STATUSES = {"technical_blocker", "blocked", "health_only"}
RUNNING_RAW_STATUSES = {"started", "running", "waiting", "queued", "pending", "scheduled"}

STEP_TO_PHASE = {step: step for step in STEP_ORDER} | {alias: canonical for alias, canonical in STEP_ALIASES.items()}


def parse_ts(value: Any) -> datetime | None:
    if not value:
        return None
    if isinstance(value, datetime):
        return value if value.tzinfo else value.replace(tzinfo=timezone.utc)
    try:
        parsed = datetime.fromisoformat(str(value).replace("Z", "+00:00"))
        return parsed if parsed.tzinfo else parsed.replace(tzinfo=timezone.utc)
    except Exception:
        return None


def _lower(value: Any) -> str:
    return str(value or "").strip().lower()


def _first_nonempty(*values: Any) -> str:
    for value in values:
        if value is not None and str(value).strip():
            return str(value)
    return ""

def _owner_from_bucket_source(bucket_source: str | None) -> str:
    if not bucket_source:
        return ""
    return str(bucket_source).split("/", 1)[0].strip()


def _job_url_from_view_sources(*, bucket_source: str, summary: dict[str, Any], state: dict[str, Any], launch: dict[str, Any]) -> str:
    explicit = summary.get("job_url") or state.get("job_url") or launch.get("job_url")
    if explicit:
        return str(explicit)
    job_id = summary.get("job_id") or state.get("job_id") or launch.get("job_id")
    owner = (
        summary.get("created_by")
        or summary.get("username")
        or summary.get("owner")
        or state.get("created_by")
        or state.get("username")
        or state.get("owner")
        or launch.get("created_by")
        or launch.get("username")
        or launch.get("owner")
        or _owner_from_bucket_source(bucket_source)
    )
    if job_id and owner:
        return f"https://huggingface.co/jobs/{owner}/{job_id}"
    return ""


def _latest_activity_at(bundle: dict[str, Any], summary: dict[str, Any], state: dict[str, Any], launch: dict[str, Any]) -> datetime | None:
    candidates: list[datetime] = []
    for event in bundle.get("events") or []:
        ts = parse_ts(event.get("ts") if isinstance(event, dict) else None)
        if ts:
            candidates.append(ts)
    for source in (summary, state, launch, bundle.get("summary_file") or {}):
        for key in ("updated_at", "finished_at", "created_at", "started_at"):
            ts = parse_ts(source.get(key) if isinstance(source, dict) else None)
            if ts:
                candidates.append(ts)
    return max(candidates) if candidates else None


def _created_at(summary: dict[str, Any], state: dict[str, Any], launch: dict[str, Any]) -> datetime | None:
    for source in (summary, state, launch):
        ts = parse_ts(source.get("created_at") if isinstance(source, dict) else None)
        if ts:
            return ts
    return None


def _raw_statuses(bundle: dict[str, Any]) -> set[str]:
    summary = bundle.get("summary") or {}
    state = bundle.get("state") or {}
    launch = bundle.get("launch") or {}
    gate = bundle.get("inference_gate") or {}
    smoke = bundle.get("generation_smoke") or {}
    hardware = bundle.get("hardware_strategy") or {}
    blockers = bundle.get("technical_blockers") or {}

    values = {
        _lower(summary.get("status")),
        _lower(state.get("status")),
        _lower(state.get("gate_status")),
        _lower(launch.get("status")),
        _lower(gate.get("status")),
        _lower(smoke.get("status")),
        _lower(hardware.get("status")),
        _lower(blockers.get("status")),
    }
    # Event-level statuses describe individual steps and must not by themselves
    # turn a whole run into success/failure. The product phase is derived from
    # events separately in derive_product_phase().
    return {v for v in values if v}


def requires_manual_action(bundle: dict[str, Any]) -> bool:
    summary = bundle.get("summary") or {}
    gate = bundle.get("inference_gate") or {}
    hardware = bundle.get("hardware_strategy") or {}
    statuses = _raw_statuses(bundle)
    return bool(
        summary.get("manual_hardware_required")
        or gate.get("manual_hardware_required")
        or hardware.get("manual_action_required")
        or statuses.intersection(MANUAL_RAW_STATUSES)
    )


def has_technical_blocker(bundle: dict[str, Any]) -> bool:
    blockers = bundle.get("technical_blockers") or {}
    blocker_items = blockers.get("blockers") if isinstance(blockers, dict) else None
    return bool(blocker_items or _raw_statuses(bundle).intersection(BLOCKED_RAW_STATUSES))


def normalize_run_status(
    bundle: dict[str, Any],
    *,
    now: datetime | None = None,
    stale_after: timedelta = timedelta(hours=6),
) -> dict[str, Any]:
    """Return canonical status flags for the product UI."""
    now = now or datetime.now(timezone.utc)
    summary = bundle.get("summary") or {}
    state = bundle.get("state") or {}
    launch = bundle.get("launch") or {}
    statuses = _raw_statuses(bundle)
    manual = requires_manual_action(bundle)
    blocker = has_technical_blocker(bundle)

    if statuses.intersection(CANCELLED_RAW_STATUSES):
        global_status = "cancelled"
        verdict = "cancelled"
    elif manual:
        global_status = "waiting_manual_action"
        verdict = "manual_action_required"
    elif statuses.intersection(SUCCESS_RAW_STATUSES):
        global_status = "succeeded"
        verdict = "passed"
    elif statuses.intersection(PARTIAL_RAW_STATUSES):
        global_status = "partial"
        verdict = "partial_validation"
    elif statuses.intersection(FAILED_RAW_STATUSES):
        global_status = "failed"
        verdict = "failed"
    elif blocker:
        global_status = "blocked"
        verdict = "technical_blocker"
    elif statuses.intersection(RUNNING_RAW_STATUSES) or bundle.get("events") or launch:
        global_status = "running"
        verdict = "pending"
    else:
        global_status = "unknown"
        verdict = "unknown"

    latest = _latest_activity_at(bundle, summary, state, launch)
    created = _created_at(summary, state, launch)
    reference = latest or created
    is_terminal = global_status in TERMINAL_GLOBAL_STATUSES or global_status in {"succeeded"}
    is_stale = False
    if reference and not is_terminal and now - reference > stale_after:
        global_status = "stale"
        verdict = "stale"
        is_stale = True

    return {
        "global_status": global_status,
        "raw_status": _first_nonempty(summary.get("status"), state.get("status"), launch.get("status"), "unknown"),
        "verdict": verdict,
        "requires_manual_action": manual,
        "manual_action_type": "hardware" if manual else "",
        "has_technical_blocker": blocker,
        "has_target_space": bool(summary.get("target_space") or state.get("target_space") or launch.get("target_space")),
        "has_job_url": bool(summary.get("job_url") or state.get("job_url") or launch.get("job_url") or summary.get("job_id") or state.get("job_id") or launch.get("job_id")),
        "has_live_api_result": bool((bundle.get("generation_smoke") or {}).get("ok") or (bundle.get("generation_smoke") or {}).get("status") == "success"),
        "is_terminal": global_status in {"succeeded", "partial", "failed", "blocked", "waiting_manual_action", "cancelled"},
        "is_pollable": global_status in {"queued", "running", "validating", "unknown"},
        "is_stale": is_stale,
        "latest_activity_at": latest.isoformat() if latest else "",
    }


def derive_product_phase(bundle: dict[str, Any], status_model: dict[str, Any]) -> str:
    if status_model["global_status"] in {"succeeded", "partial"}:
        return "done"
    if status_model["global_status"] in {"failed", "blocked", "stale", "cancelled"}:
        return "failure"
    if status_model["requires_manual_action"]:
        return "inference_gate"

    events = [e for e in (bundle.get("events") or []) if isinstance(e, dict)]
    for event in reversed(events):
        step = _lower(event.get("step"))
        message = _lower(event.get("message"))
        status = _lower(event.get("status"))
        if "patch" in step or "repair" in step or "patched" in message or "restart" in message:
            return "hardware_strategy"
        if "missing" in message or "error" in message or status in FAILED_RAW_STATUSES:
            return "hardware_strategy"
        phase = STEP_TO_PHASE.get(step)
        if phase:
            return phase

    summary = bundle.get("summary") or {}
    if summary.get("target_space"):
        return "hardware_strategy"
    if bundle.get("launch"):
        return "bootstrap"
    return "bootstrap"


def build_pipeline(phase: str, status_model: dict[str, Any]) -> list[dict[str, Any]]:
    phase_ids = [s["id"] for s in PRODUCT_STEPS]
    current_index = phase_ids.index(phase) if phase in phase_ids else 0
    global_status = status_model["global_status"]

    pipeline: list[dict[str, Any]] = []
    for index, step in enumerate(PRODUCT_STEPS):
        if global_status == "succeeded":
            step_status = "completed"
        elif index < current_index:
            step_status = "completed"
        elif index == current_index:
            if global_status == "failed":
                step_status = "failed"
            elif global_status in {"blocked", "waiting_manual_action", "stale"}:
                step_status = "blocked"
            else:
                step_status = "running"
        else:
            step_status = "pending"
        pipeline.append({**step, "status": step_status})
    return pipeline


def _agent_for_event(event: dict[str, Any]) -> str:
    step = _lower(event.get("step"))
    if step in {"model_analysis", "bucket_ready", "job_launched", "bootstrap"}:
        return "Planner Agent"
    if step in {"workspace", "node", "pi_install", "pi_config", "pi_run", "repair", "patch"}:
        return "Coder Agent"
    if step in {"create_space", "upload_files", "hardware", "hardware_preferred", "hardware_fallback"}:
        return "Hub Agent"
    if step in {"api_validation", "generation_smoke", "inference_gate"}:
        return "Tester Agent"
    if _lower(event.get("status")) in FAILED_RAW_STATUSES:
        return "Diagnostician Agent"
    return "Factory Agent"


def _severity_for_event(event: dict[str, Any]) -> str:
    status = _lower(event.get("status"))
    message = _lower(event.get("message"))
    if status in FAILED_RAW_STATUSES or "traceback" in message or "modulenotfound" in message:
        return "error"
    if status in {"warning", "manual_hardware_required"} or "manual" in message:
        return "warning"
    if status in SUCCESS_RAW_STATUSES:
        return "success"
    if status in PARTIAL_RAW_STATUSES:
        return "warning"
    if status in RUNNING_RAW_STATUSES:
        return "running"
    return "info"


def build_activity_feed(bundle: dict[str, Any], *, limit: int = 40) -> list[dict[str, Any]]:
    events = [e for e in (bundle.get("events") or []) if isinstance(e, dict)]
    if not events and bundle.get("launch"):
        launch = bundle.get("launch") or {}
        events = [
            {
                "ts": launch.get("created_at") or "",
                "step": "job_launched",
                "status": launch.get("status") or "running",
                "message": f"Build job launched for {launch.get('target_space') or 'target Space'}",
            }
        ]
    feed: list[dict[str, Any]] = []
    for event in events[-limit:]:
        feed.append(
            {
                "ts": event.get("ts") or event.get("created_at") or "",
                "step": event.get("step") or "",
                "status": event.get("status") or "",
                "message": event.get("message") or event.get("step") or "Event received",
                "severity": _severity_for_event(event),
                "agent": _agent_for_event(event),
            }
        )
    return feed


def build_diagnostics(bundle: dict[str, Any], status_model: dict[str, Any], phase: str) -> dict[str, Any]:
    summary = bundle.get("summary") or {}
    smoke = bundle.get("generation_smoke") or {}
    gate = bundle.get("inference_gate") or {}
    hardware = bundle.get("hardware_strategy") or {}
    blockers = bundle.get("technical_blockers") or {}
    blocker_items = blockers.get("blockers") if isinstance(blockers, dict) else []

    issue_title = ""
    issue_detail = ""
    issue_status = ""
    if blocker_items:
        first = blocker_items[0]
        issue_title = _first_nonempty(first.get("type"), first.get("name"), "Technical blocker") if isinstance(first, dict) else "Technical blocker"
        issue_detail = _first_nonempty(first.get("claim"), first.get("reason"), first.get("message")) if isinstance(first, dict) else str(first)
        issue_status = "open"
    elif status_model["requires_manual_action"]:
        issue_title = "Manual hardware required"
        issue_detail = "Automatic hardware selection was not available. Choose hardware in Space settings, then run Space Test."
        issue_status = "action_required"
    elif status_model["global_status"] == "failed":
        issue_title = "Run failed"
        issue_detail = "Inspect logs and run artifacts for the failing step."
        issue_status = "open"

    health_passed = bool((gate.get("implementation_signals") or {}).get("health_passed") or smoke.get("health_passed"))
    smoke_ok = bool(smoke.get("ok") or smoke.get("status") == "success")
    build_ok = phase in {"api_validation", "live_wait", "generation_smoke", "inference_gate", "report_write", "done"} or status_model["global_status"] == "succeeded"

    return {
        "build_status": "passed" if build_ok else ("blocked" if status_model["global_status"] in {"blocked", "waiting_manual_action", "failed"} else "building"),
        "api_status": "passed" if smoke_ok else ("blocked" if status_model["global_status"] in {"blocked", "failed"} else "pending"),
        "tests_status": "passed" if smoke_ok or health_passed else ("blocked" if status_model["global_status"] in {"blocked", "failed"} else "pending"),
        "verdict_status": status_model["verdict"],
        "zerogpu_rules": [
            {"label": "Gradio interface", "status": "ok"},
            {"label": "Private Space", "status": "ok" if summary.get("target_space") else "pending"},
            {"label": "ZeroGPU-first strategy", "status": "ok" if "zero" in _lower(summary.get("selected_hardware") or hardware.get("preferred_space_hardware") or "zero") else "pending"},
            {"label": "Live API verification", "status": "ok" if smoke_ok else "pending"},
        ],
        "issue": {"title": issue_title, "detail": issue_detail, "status": issue_status},
    }


def build_space_test_model(bundle: dict[str, Any], status_model: dict[str, Any]) -> dict[str, Any]:
    smoke = bundle.get("generation_smoke") or {}
    summary = bundle.get("summary") or {}
    return {
        "target_space": summary.get("target_space") or "",
        "target_space_url": summary.get("target_space_url") or "",
        "endpoint": smoke.get("api_name") or smoke.get("endpoint") or "/generate",
        "status": "passed" if smoke.get("ok") or smoke.get("status") == "success" else "pending",
        "latency_seconds": smoke.get("latency_seconds") or summary.get("latency_seconds"),
        "expected_output_type": summary.get("expected_output_type") or smoke.get("expected_output_type") or "",
        "verdict": status_model["verdict"],
        "output_artifact": smoke.get("output_artifact") or smoke.get("artifact_url") or "",
    }


def build_run_view_model(
    run_id: str,
    bundle: dict[str, Any],
    *,
    bucket_source: str,
    now: datetime | None = None,
) -> dict[str, Any]:
    summary = bundle.get("summary") or {}
    state = bundle.get("state") or {}
    status_model = normalize_run_status(bundle, now=now)
    phase = derive_product_phase(bundle, status_model)
    elapsed_seconds = None
    current_now = now or datetime.now(timezone.utc)
    created = parse_ts(summary.get("started_at") or state.get("started_at") or summary.get("created_at") or state.get("created_at"))
    latest = parse_ts(status_model.get("latest_activity_at"))
    if created:
        end = latest if status_model.get("is_terminal") and latest else current_now
        elapsed_seconds = int((end - created).total_seconds())
    links = {
        "job_url": _job_url_from_view_sources(bucket_source=bucket_source, summary=summary, state=state, launch=bundle.get("launch") or {}),
        "target_space_url": summary.get("target_space_url") or "",
        "target_space_settings_url": f"{summary.get('target_space_url')}/settings" if summary.get("target_space_url") else "",
        "artifacts_url": summary.get("artifacts_url") or f"https://huggingface.co/buckets/{bucket_source}/tree/{_runs_prefix()}/{run_id}",
    }
    return {
        "schema_version": "run_view_model.v1",
        "run_id": run_id,
        "bucket_source": bucket_source,
        "header": {
            "title": _first_nonempty(summary.get("title"), f"Build Space for {summary.get('model_id')}", run_id),
            "status": status_model["global_status"],
            "status_label": status_model["global_status"].replace("_", " ").title(),
            "raw_status": status_model["raw_status"],
            "space": summary.get("target_space") or "",
            "space_url": summary.get("target_space_url") or "",
            "current_phase": phase,
            "current_phase_label": next((s["label"] for s in PRODUCT_STEPS if s["id"] == phase), phase),
            "elapsed_seconds": max(0, elapsed_seconds or 0),
            "started_at": summary.get("created_at") or state.get("created_at") or "",
            "updated_at": status_model["latest_activity_at"],
        },
        "status_model": status_model,
        "pipeline": build_pipeline(phase, status_model),
        "timeline_model": build_run_timeline_model(bundle),
        "activity": build_activity_feed(bundle),
        "diagnostics": build_diagnostics(bundle, status_model, phase),
        "space_test": build_space_test_model(bundle, status_model),
        "actions": {
            "can_resume": status_model["global_status"] in {"running", "stale", "unknown"},
            "can_stop": status_model["global_status"] in {"running", "queued", "unknown"},
            "can_open_space": bool(summary.get("target_space_url")),
            "can_validate": bool(summary.get("target_space")),
            "requires_manual_action": status_model["requires_manual_action"],
        },
        "links": links,
    }


def is_resumable_summary(summary: dict[str, Any], *, now: datetime | None = None, stale_after: timedelta = timedelta(hours=6)) -> bool:
    """Best-effort resumability test for lightweight /api/runs summaries."""
    status = _lower(summary.get("status"))
    if status in SUCCESS_RAW_STATUSES or status in PARTIAL_RAW_STATUSES or status in FAILED_RAW_STATUSES or status in BLOCKED_RAW_STATUSES or status in MANUAL_RAW_STATUSES:
        return False
    if "success" in status or "failed" in status or "blocker" in status or "manual" in status:
        return False
    now = now or datetime.now(timezone.utc)
    latest = parse_ts(summary.get("updated_at") or summary.get("created_at"))
    if latest and now - latest > stale_after:
        return False
    return status in RUNNING_RAW_STATUSES or status in {"unknown", ""}


def find_latest_resumable_run(summaries: list[dict[str, Any]], *, now: datetime | None = None) -> dict[str, Any] | None:
    candidates = [s for s in summaries if isinstance(s, dict) and is_resumable_summary(s, now=now)]
    if not candidates:
        return None
    return sorted(candidates, key=lambda s: str(s.get("updated_at") or s.get("created_at") or s.get("run_id")), reverse=True)[0]