#!/usr/bin/env python3
"""Unit tests for idatui.pool (worker residency: LRU + memory budget).

Pure stdlib with a fake client injected, so the eviction policy is testable
without spawning real idalib workers.

    python tests/test_pool.py
"""
import os
import sys
import tempfile

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
from idatui.pool import WorkerPool  # noqa: E402
from idatui.project import Project  # noqa: E402

PASS = FAIL = 0


def check(name, cond, detail=""):
    global PASS, FAIL
    if cond:
        PASS += 1
        print(f"  ok   {name}")
    else:
        FAIL += 1
        print(f"  FAIL {name}   {detail}")


class FakeClient:
    """Stands in for a WorkerClient: records saves/closes, reports fixed memory."""

    def __init__(self, ref, mem=100):
        self.ref = ref
        self.mem = mem
        self.saved = 0
        self.closed = False
        self.connected = False

    def connect(self, progress=None, **kw):
        self.connected = True
        return self

    def call(self, tool, **kw):
        if tool == "idb_save":
            self.saved += 1
        return {}

    def close(self, grace=None):
        self.closed = True


def _mkproject(tmp, n=4, size=64):
    src = os.path.join(tmp, "src")
    os.makedirs(src, exist_ok=True)
    paths = []
    for i in range(n):
        p = os.path.join(src, f"bin{i}")
        with open(p, "wb") as f:
            f.write(b"\x7fELF" + bytes(size))
        paths.append(p)
    return Project.create(os.path.join(tmp, "p.json"), paths, name="p")


def main() -> int:
    with tempfile.TemporaryDirectory() as tmp:
        proj = _mkproject(tmp)
        made = {}

        def spawn(ref, ttl):
            c = FakeClient(ref, mem=100)
            made[ref.label] = c
            return c

        pool = WorkerPool(proj, budget_mb=350, spawn=spawn,
                          mem_fn=lambda c: c.mem)

        # -- lazy spawn + reuse -------------------------------------------- #
        a = pool.get("bin0")
        check("get() spawns a worker on first use", a is made["bin0"] and a.connected)
        check("get() stages the binary first",
              os.path.isfile(proj.by_label("bin0").staged))
        check("get() reuses the resident worker", pool.get("bin0") is a)
        check("resident() reports it", pool.resident() == ["bin0"], pool.resident())

        # -- LRU ordering ---------------------------------------------------- #
        pool.get("bin1")
        pool.get("bin2")
        pool.get("bin0")  # touch: bin0 becomes most-recent
        check("LRU order tracks use", pool.resident() == ["bin1", "bin2", "bin0"],
              pool.resident())

        # -- budget eviction -------------------------------------------------- #
        check("pool reports its memory", pool.memory_mb() == 300, pool.memory_mb())
        pool.get("bin3")  # 400MB > 350MB budget -> evict LRU (bin1)
        check("exceeding the budget evicts the least-recently-used",
              pool.evicted == ["bin1"] and not pool.is_resident("bin1"),
              f"evicted={pool.evicted} resident={pool.resident()}")
        check("the just-spawned worker is never the victim", pool.is_resident("bin3"))
        check("eviction saves the database first", made["bin1"].saved == 1)
        check("eviction closes the worker", made["bin1"].closed)
        check("pool is back within budget", pool.memory_mb() <= pool.budget_mb,
              f"{pool.memory_mb()}/{pool.budget_mb}")

        # -- the active binary is never evicted ------------------------------- #
        pool.set_active("bin2")
        check("set_active touches the LRU", pool.resident()[-1] == "bin2",
              pool.resident())
        pool.get("bin1")  # over budget again -> must evict, but not bin2
        check("the active binary survives eviction", pool.is_resident("bin2"),
              f"resident={pool.resident()}")

        # -- pinning ---------------------------------------------------------- #
        pool.close_all()
        pool2 = WorkerPool(proj, budget_mb=250, spawn=spawn, mem_fn=lambda c: c.mem)
        pool2.get("bin0")
        pool2.pin("bin0")
        pool2.get("bin1")
        pool2.get("bin2")  # 300 > 250 -> evict, but bin0 is pinned
        check("pinned binaries are never evicted", pool2.is_resident("bin0"),
              f"resident={pool2.resident()} evicted={pool2.evicted}")
        check("an unpinned one went instead", "bin1" in pool2.evicted, pool2.evicted)

        # -- everything pinned/active: stop evicting rather than thrash -------- #
        pool2.pin("bin2")
        pool2.set_active("bin2")
        n_before = len(pool2.evicted)
        pool2._enforce_budget()
        check("nothing evictable -> gives up instead of thrashing",
              len(pool2.evicted) == n_before, pool2.evicted)

        # -- status for the switcher UI ---------------------------------------- #
        st = {s["label"]: s for s in pool2.status()}
        check("status() covers every project binary", len(st) == 4, list(st))
        check("status() marks resident/pinned/active",
              st["bin0"]["resident"] and st["bin0"]["pinned"]
              and st["bin2"]["active"] and not st["bin3"]["resident"],
              f"{st}")

        # -- teardown ----------------------------------------------------------- #
        pool2.close_all()
        check("close_all() closes every worker",
              not pool2.resident() and all(c.closed for c in made.values()))
        check("close_all() clears the active binary", pool2.active is None)

        # -- unknown label -------------------------------------------------------- #
        try:
            pool2.get("nope")
            check("an unknown label raises KeyError", False, "no raise")
        except KeyError:
            check("an unknown label raises KeyError", True)

        # -- default budget comes from the project's memory_pct ------------------- #
        pool3 = WorkerPool(proj, spawn=spawn, mem_fn=lambda c: c.mem)
        check("default budget is derived, not a fixed worker count",
              pool3.budget_mb >= 256, pool3.budget_mb)

    # -- prewarm: speculative, and never at the cost of a real binary ------ #
    with tempfile.TemporaryDirectory() as tmp:
        proj = _mkproject(tmp, n=3)
        made2 = {}

        def spawn2(ref, ttl):
            c = FakeClient(ref, mem=100)
            made2[ref.label] = c
            return c

        pool = WorkerPool(proj, budget_mb=250, spawn=spawn2,
                          mem_fn=lambda c: c.mem)
        labels = [r.label for r in proj.refs]
        a, b, c_ = labels[0], labels[1], labels[2]
        pool.get(a)
        pool.set_active(a)
        check("prewarm warms a binary when the budget has room",
              pool.prewarm(b) is True and b in pool.resident(), f"{pool.resident()}")
        check("prewarm is a no-op for something already resident",
              pool.prewarm(b) is False)
        # 2 x 100MB resident, estimate 100 more -> 300 > 250: must refuse
        check("prewarm refuses rather than making room",
              pool.prewarm(c_) is False and c_ not in pool.resident(),
              f"resident={pool.resident()} mem={pool.memory_mb()}/{pool.budget_mb}")
        check("refusing to prewarm evicts nothing",
              set(pool.resident()) == {a, b}, f"{pool.resident()}")
        check("prewarm ignores a label outside the project",
              pool.prewarm("nope") is False)

    print(f"\n{PASS} passed, {FAIL} failed")
    return 1 if FAIL else 0


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