"""The manifest's ``engines`` must be satisfiable by a toolchain we can actually ship.

`engine-strict=true` in `.npmrc` makes `engines` a hard gate on every
`npm ci` / `npm install` — the installer's workspace step, `hermes update`'s
dependency refresh, and CI alike. So a floor nobody's toolchain can meet is
not a strict-hygiene win; it is a total install outage.

That is exactly what happened: `engines.npm` was raised to `>=12.0.0` while
**no Node release bundles npm 12** (Node 26 ships 11.17.0, 24 ships 11.16.0,
22 ships 10.9.8). Every fresh install died at the first `npm ci`, and
`hermes update` left installs in a mixed state. These tests encode the
invariants that would have caught it.

Deliberately behavioral, not a snapshot: nothing here pins a version we
expect to change. Each test asserts a *relationship* — between the floor we
declare and the toolchain that has to satisfy it.
"""

from __future__ import annotations

import json
from pathlib import Path

import pytest

REPO_ROOT = Path(__file__).resolve().parents[1]

# npm releases bundled with a Node major, newest-per-major. Not a catalog
# snapshot: the point is that *some* real, shipping toolchain must clear the
# floor, and these are the ones users actually arrive with.
_STOCK_NPM_BY_NODE_MAJOR = {
    20: "10.8.2",
    22: "10.9.8",
    24: "11.16.0",
    26: "11.17.0",
}

def _root_manifest() -> dict:
    return json.loads((REPO_ROOT / "package.json").read_text())

def _pm_lock():
    from pm.lock import Lockfile

    return Lockfile(REPO_ROOT / "pm" / "lock.json")

def _parse_major_minor_patch(version: str) -> tuple[int, int, int]:
    parts = version.split("-", 1)[0].split(".")
    nums = [int(p) for p in parts[:3]]
    while len(nums) < 3:
        nums.append(0)
    return nums[0], nums[1], nums[2]

def _satisfies_clause(version: str, clause: str) -> bool:
    """Evaluate one `>=x.y.z` / `<x.y.z` / `^x.y.z` comparator against *version*."""
    clause = clause.strip()
    if clause.startswith("^"):
        bound = clause[1:].strip()
        have = _parse_major_minor_patch(version)
        want = _parse_major_minor_patch(bound)
        # ^x.y.z allows >=x.y.z within the same major (x > 0).
        return have[0] == want[0] and have >= want
    for op in (">=", "<=", "<", ">", "="):
        if clause.startswith(op):
            bound = clause[len(op) :].strip()
            break
    else:
        op, bound = "=", clause
    have = _parse_major_minor_patch(version)
    want = _parse_major_minor_patch(bound)
    if op == ">=":
        return have >= want
    if op == "<=":
        return have <= want
    if op == "<":
        return have < want
    if op == ">":
        return have > want
    return have == want

def _satisfies_range(version: str, spec: str) -> bool:
    """Evaluate the `A || B` / space-joined-AND subset of semver we author."""
    for alternative in spec.split("||"):
        clauses = [c for c in alternative.strip().split() if c]
        if clauses and all(_satisfies_clause(version, c) for c in clauses):
            return True
    return False

class TestEnginesAreSatisfiable:
    def test_npm_floor_is_met_by_a_shipping_node(self):
        """Some stock Node must bundle an npm our floor accepts.

        Without this, a fresh install cannot run `npm ci` at all: the
        installer provisions a Node from nodejs.org and immediately uses the
        npm that came with it.
        """
        npm_range = _root_manifest()["engines"]["npm"]
        satisfying = {
            major: npm
            for major, npm in _STOCK_NPM_BY_NODE_MAJOR.items()
            if _satisfies_range(npm, npm_range)
        }
        assert satisfying, (
            f"engines.npm is {npm_range!r}, which no shipping Node bundles "
            f"(checked {_STOCK_NPM_BY_NODE_MAJOR}). With engine-strict=true "
            "every fresh install fails at the first `npm ci`."
        )

    def test_node_floor_is_met_by_the_managed_runtime(self):
        """The Node PM provisions must clear engines.node."""
        node_range = _root_manifest()["engines"]["node"]
        managed_node = _pm_lock().version("node")
        assert managed_node, "pm/lock.json does not pin node"
        assert _satisfies_range(managed_node, node_range), (
            f"engines.node is {node_range!r} but PM provisions Node "
            f"{managed_node}. The runtime we ship must satisfy the floor we "
            "declare, or the install we just performed cannot install deps."
        )

    def test_managed_npm_is_accepted_by_the_engines(self):
        """The npm PM provisions must clear engines.npm, or fresh
        Hermes-managed installs die at `npm ci` with EBADENGINE (#80769).
        """
        npm_range = _root_manifest()["engines"]["npm"]
        managed_npm = _pm_lock().version("npm")
        assert managed_npm, "pm/lock.json does not pin npm"
        assert _satisfies_range(managed_npm, npm_range), (
            f"PM provisions npm {managed_npm}, but engines.npm is "
            f"{npm_range!r}. A fresh Hermes-managed install cannot run npm ci."
        )

class TestExcludedNpmBand:
    """npm 11.10–11.16 honor `min-release-age` but ignore `min-release-age-exclude`.

    `.npmrc` sets both, so that band applies the 14-day age gate to packages
    we deliberately exempted and installs fail with ETARGET. The floor must
    keep excluding them.
    """

    @pytest.mark.parametrize("bad_npm", ["11.10.0", "11.12.1", "11.16.0"])
    def test_band_that_ignores_the_exclude_list_is_rejected(self, bad_npm):
        npm_range = _root_manifest()["engines"]["npm"]
        assert not _satisfies_range(bad_npm, npm_range), (
            f"engines.npm {npm_range!r} accepts npm {bad_npm}, which supports "
            "min-release-age but not min-release-age-exclude — it will fail "
            "ETARGET on any freshly published dependency in .npmrc's exclude list."
        )

    @pytest.mark.parametrize("good_npm", ["10.9.8", "11.17.0", "12.0.2"])
    def test_versions_handling_the_exclude_list_are_accepted(self, good_npm):
        npm_range = _root_manifest()["engines"]["npm"]
        assert _satisfies_range(good_npm, npm_range), (
            f"engines.npm {npm_range!r} rejects npm {good_npm}, which handles "
            ".npmrc correctly and should be usable."
        )

class TestManifestMirrors:
    def test_lockfile_engines_match_the_manifest(self):
        """A stale lockfile mirror re-imposes the old floor on `npm ci`."""
        manifest = _root_manifest()["engines"]
        lock = json.loads((REPO_ROOT / "package-lock.json").read_text())
        assert lock["packages"][""]["engines"] == manifest

def _normalize_range(spec: str) -> str:
    """Normalize the wilder styles real deps publish so our tiny evaluator
    can read them: collapse space after operators (``">= 10"``), drop ``v``
    prefixes (``">=v12.22.7"``), and rewrite ``x``/``*`` wildcards to floors.
    """
    import re

    spec = re.sub(r"(>=|<=|>|<|\^|~|=)\s+", r"\1", spec)
    spec = re.sub(r"(>=|<=|>|<|\^|~|=)v", r"\1", spec)
    # "6.x" / "10.*" -> "^6.0.0"-ish floor within the major; ">= 10.*" -> ">=10.0.0"
    spec = re.sub(r"(\d+)\.[x*](?:\.[x*])?", r"\1.0.0", spec)
    return spec

class TestDeclaredFloorsClearTheLockedTree:
    """Every Node version our own gates accept must survive `npm ci`.

    The class of outage this pins: the installers' version gates
    (node_satisfies_build in install.sh, Test-NodeVersionOk in install.ps1)
    and `engines.node` are hand-maintained, while the *real* floor is
    whatever the strictest locked dependency demands. When they drift, a
    user's system Node clears every gate we own and then dies at
    `npm install` with EBADENGINE under engine-strict=true.

    Aug 2026 instance: @babel/* 8.x requires `^22.18.0 || >=24.11.0`; our
    engines arm said `^24.0.0`, so Node 24.4 passed the installer and the
    manifest and failed on 28 babel packages.
    """

    def _arm_floors(self, node_range: str) -> list[str]:
        floors = []
        for arm in node_range.split("||"):
            arm = arm.strip()
            for op in ("^", ">=", "="):
                if arm.startswith(op):
                    floors.append(arm[len(op):].strip())
                    break
            else:
                floors.append(arm)
        return floors

    def _locked_node_ranges(self) -> dict[str, str]:
        lock = json.loads((REPO_ROOT / "package-lock.json").read_text())
        ranges: dict[str, str] = {}
        for path, meta in lock["packages"].items():
            engines = meta.get("engines")
            if not isinstance(engines, dict):
                continue
            node_range = engines.get("node")
            if isinstance(node_range, str) and node_range.strip() not in ("", "*"):
                ranges.setdefault(node_range, path)
        return ranges

    def test_every_engines_arm_floor_clears_every_locked_dependency(self):
        node_range = _root_manifest()["engines"]["node"]
        violations = []
        for floor in self._arm_floors(node_range):
            for dep_range, example in self._locked_node_ranges().items():
                if not _satisfies_range(floor, _normalize_range(dep_range)):
                    violations.append((floor, dep_range, example))
        assert not violations, (
            "engines.node arms admit Node versions the locked dependency "
            "tree rejects — those users pass every install gate and then "
            "die at `npm install` with EBADENGINE (engine-strict=true). "
            "Raise the arm floor (and the installer gates: "
            "node_satisfies_build in scripts/install.sh, Test-NodeVersionOk "
            f"in scripts/install.ps1) or relax the dep. Violations: {violations}"
        )