"""Expand a discovered app-id list into CI deploy-matrix entries.

A role whose matrix-deploy declares more variants than a single runner should
iterate is split into bundles of consecutive variant indices, one runner per
bundle — e.g. a 5-variant role becomes ``0,1,2`` and ``3,4``. A new bundle opens
as soon as the current one would exceed ``INFINITO_VARIANT_BUNDLE_SIZE`` variants
(default 3) OR ``INFINITO_VARIANT_BUNDLE_MAX_STORAGE`` cumulative ``min_storage``
(default 350GB), so storage-heavy variants are not stacked onto one runner that
would then run too long. Roles that fit one runner stay a single entry but still
carry their full ``0,…,N-1`` variant CSV, so every job name shows the variants it
covers.

Each entry is ``{"apps": <id>, "variant": "<csv>", "variant_slug": "<dashed>"}``;
``variant`` is empty only for a role that declares no variants (a plain base
deploy). The ``variant`` slice is threaded
through to ``cli.administration.deploy.development`` via the ``variant``
environment variable (consumed by ``--variant``), so a runner only iterates the
rounds in its bundle. ``variant_slug`` is a comma-free copy for artifact/job
names (GitHub Actions expressions have no string-replace function).

In swarm mode (``INFINITO_DEPLOY_MODE=swarm``) the split is one variant per
runner (bundle size 1) and variants whose ``meta/variants.yml`` override
disables every service are dropped: the all-enabled variant already exercises
the role, so a bare all-off deploy adds no coverage. Surviving variants keep
their ABSOLUTE index, so the emitted ``variant`` index still maps to the same
``meta/variants.yml`` round the deploy planner resolves. Compose mode is
unchanged.
"""

from __future__ import annotations

import json
import os
import sys
from typing import TYPE_CHECKING

from humanfriendly import parse_size

from utils import PROJECT_ROOT
from utils.cache.applications import (
    get_variant_overrides_only,
    get_variants,
)
from utils.roles.applications.services.registry import (
    build_service_registry_from_applications,
    load_applications_from_roles_dir,
)
from utils.roles.applications.services.resources import (
    aggregate,
    collect_role_resources,
)
from utils.roles.applications.services.variant_status import (
    deployable_variant_indices,
)

if TYPE_CHECKING:
    from collections.abc import Iterable, Mapping, Sequence
    from pathlib import Path
    from typing import Any

DEFAULT_BUNDLE_SIZE = 3
DEFAULT_MAX_STORAGE = "350GB"
ROLES_DIR = PROJECT_ROOT / "roles"


def resolve_bundle_size(raw: str | None = None) -> int:
    if raw is None:
        raw = os.environ.get("INFINITO_VARIANT_BUNDLE_SIZE")
    value = (raw or "").strip()
    if not value:
        return DEFAULT_BUNDLE_SIZE
    try:
        size = int(value)
    except ValueError:
        raise ValueError(
            f"INFINITO_VARIANT_BUNDLE_SIZE must be an integer, got {value!r}"
        ) from None
    if size < 1:
        raise ValueError("INFINITO_VARIANT_BUNDLE_SIZE must be >= 1")
    return size


def resolve_max_storage(raw: str | None = None) -> int | None:
    if raw is None:
        raw = os.environ.get("INFINITO_VARIANT_BUNDLE_MAX_STORAGE")
    value = (raw or "").strip()
    if not value:
        value = DEFAULT_MAX_STORAGE
    if value.lower() in ("0", "off", "none"):
        return None
    try:
        return int(parse_size(value))
    except Exception:
        raise ValueError(
            f"INFINITO_VARIANT_BUNDLE_MAX_STORAGE must be a size like {DEFAULT_MAX_STORAGE!r}, "
            f"got {value!r}"
        ) from None


def _pack_indices(
    indices: Sequence[int],
    bundle_size: int,
    storages: Sequence[int | None] | None = None,
    max_storage_bytes: int | None = None,
) -> list[list[int]]:
    """Greedily pack the given (absolute) variant indices into bundles, opening
    a new bundle as soon as the current one would exceed ``bundle_size``
    variants OR ``max_storage_bytes`` cumulative ``min_storage``; both counters
    reset per bundle. ``storages`` is indexed by the ABSOLUTE variant index, so
    a filtered index list still reads the right per-variant storage."""
    bundles: list[list[int]] = []
    current: list[int] = []
    current_storage = 0
    for index in indices:
        size = 0
        if storages is not None and index < len(storages):
            size = storages[index] or 0
        over_count = len(current) >= bundle_size
        over_storage = (
            max_storage_bytes is not None
            and bool(current)
            and current_storage + size > max_storage_bytes
        )
        if current and (over_count or over_storage):
            bundles.append(current)
            current = []
            current_storage = 0
        current.append(index)
        current_storage += size
    if current:
        bundles.append(current)
    return bundles


def bundle_indices(
    count: int,
    bundle_size: int,
    storages: Sequence[int | None] | None = None,
    max_storage_bytes: int | None = None,
) -> list[list[int]]:
    """Pack ``0..count-1`` into bundles. With no storage cap this matches
    ``chunk_indices``. A single variant that alone exceeds the storage cap still
    forms its own bundle."""
    return _pack_indices(list(range(count)), bundle_size, storages, max_storage_bytes)


def chunk_indices(count: int, bundle_size: int) -> list[list[int]]:
    return [
        list(range(start, min(start + bundle_size, count)))
        for start in range(0, count, bundle_size)
    ]


def variant_count(variants_per_app: Mapping[str, Sequence[Any]], app: str) -> int:
    return max(1, len(variants_per_app.get(app) or []))


def _entry(app: str, variant_csv: str) -> dict[str, str]:
    """``variant_slug`` is a comma-free copy of ``variant_csv`` for artifact/job
    names: GitHub Actions expressions have no ``replace()``, so the CSV cannot be
    sanitised in YAML."""
    return {
        "apps": app,
        "variant": variant_csv,
        "variant_slug": variant_csv.replace(",", "-"),
    }


def expand_apps(
    apps: Iterable[str],
    variants_per_app: Mapping[str, Sequence[Any]],
    bundle_size: int = DEFAULT_BUNDLE_SIZE,
    *,
    storages_per_app: Mapping[str, Sequence[int | None]] | None = None,
    max_storage_bytes: int | None = None,
    deployable_indices_per_app: Mapping[str, Sequence[int]] | None = None,
) -> list[dict[str, str]]:
    entries: list[dict[str, str]] = []
    for app in apps:
        variant_list = variants_per_app.get(app) or []
        if not variant_list:
            entries.append({"apps": app, "variant": "", "variant_slug": ""})
            continue
        indices = list(range(len(variant_list)))
        if deployable_indices_per_app is not None:
            allowed = set(deployable_indices_per_app.get(app, indices))
            indices = [i for i in indices if i in allowed]
        if not indices:
            continue
        storages = (storages_per_app or {}).get(app)
        entries.extend(
            _entry(app, ",".join(map(str, chunk)))
            for chunk in _pack_indices(
                indices, bundle_size, storages, max_storage_bytes
            )
        )
    return entries


def app_variant_storages(
    apps: Iterable[str],
    variants_per_app: Mapping[str, Sequence[Any]],
    roles_dir: Path = ROLES_DIR,
) -> dict[str, list[int | None]]:
    """Per-variant total ``min_storage`` (bytes) for each app, via the shared
    resource collection (same machinery as the ``ressources`` CLI / budget
    lint). Unknown apps and variants without storage yield ``None`` entries."""
    applications = load_applications_from_roles_dir(roles_dir)
    registry = build_service_registry_from_applications(applications)
    result: dict[str, list[int | None]] = {}
    for app in apps:
        sizes: list[int | None] = []
        for variant_config in variants_per_app.get(app) or []:
            scoped = dict(applications)
            scoped[app] = variant_config or {}
            rows: list[dict[str, Any]] = []
            collect_role_resources(
                role_name=app,
                applications=scoped,
                service_registry=registry,
                visited=set(),
                rows=rows,
                warnings=[],
                dedup=True,
            )
            sizes.append(aggregate(rows).get("min_storage_bytes"))
        result[app] = sizes
    return result


def compose_bundle_counts(
    apps: Iterable[str],
    variants_per_app: Mapping[str, Sequence[Any]],
    *,
    roles_dir: Path = ROLES_DIR,
) -> dict[str, int]:
    """Per app, the number of compose CI bundles (jobs) its variants pack into.

    Uses the same bundle-size + cumulative-``min_storage`` packing as the
    compose deploy matrix (``expand_apps`` / ``bundle_indices``), so the
    ``complexity`` report and the matrix never diverge on the job count.
    """
    apps = list(apps)
    storages = app_variant_storages(apps, variants_per_app, roles_dir)
    bundle_size = resolve_bundle_size()
    max_storage = resolve_max_storage()
    return {
        app: len(
            bundle_indices(
                variant_count(variants_per_app, app),
                bundle_size,
                storages.get(app),
                max_storage,
            )
        )
        for app in apps
    }


def _swarm_mode() -> bool:
    return (os.environ.get("INFINITO_DEPLOY_MODE") or "").strip().lower() == "swarm"


def _deployable_indices(
    apps: Iterable[str],
    overrides_per_app: Mapping[str, Sequence[Any]],
) -> dict[str, list[int]]:
    """Per app, the variant indices the swarm matrix may deploy, via the shared
    ``deployable_variant_indices`` SPOT (drops all-off variants)."""
    return {
        app: deployable_variant_indices(list(overrides_per_app.get(app) or []))
        for app in apps
    }


def main(argv: Sequence[str] | None = None) -> int:
    argv = list(sys.argv[1:] if argv is None else argv)
    raw = argv[0] if argv else sys.stdin.read()
    apps = json.loads(raw) if raw.strip() else []
    if not isinstance(apps, list):
        raise SystemExit(
            f"variant_bundles: expected a JSON array of app ids, got "
            f"{type(apps).__name__}"
        )
    variants_per_app = get_variants()
    if _swarm_mode():
        entries = expand_apps(
            apps,
            variants_per_app,
            1,
            deployable_indices_per_app=_deployable_indices(
                apps, get_variant_overrides_only()
            ),
        )
    else:
        entries = expand_apps(
            apps,
            variants_per_app,
            resolve_bundle_size(),
            storages_per_app=app_variant_storages(apps, variants_per_app),
            max_storage_bytes=resolve_max_storage(),
        )
    print(json.dumps(entries))
    return 0


if __name__ == "__main__":
    raise SystemExit(main())