#!/usr/bin/env python3
"""Layout tests for idatui.graph — pure, offline, no IDA and no Textual.

    python3 tests/test_graph.py                     # synthetic shapes
    python3 tests/test_graph.py /tmp/cfg-echo.json  # + a real CFG corpus

The corpus file is what ``experiments/cfg_dump.py`` writes. It's optional so the
suite runs anywhere, but when present it is the interesting half: real functions
are where the degenerate shapes (switch fan-out, irreducible loops, 400-block
monsters) actually live.
"""
from __future__ import annotations

import json
import os
import sys
import time

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

from idatui import graph as G  # noqa: E402

FAILED: list[str] = []
CHECKS = 0


def check(cond: bool, what: str) -> None:
    global CHECKS
    CHECKS += 1
    if not cond:
        FAILED.append(what)
        print(f"  FAIL: {what}")


def sizer(b: G.Block) -> tuple[int, int]:
    """Stand-in for the view's real sizer: width from the address text."""
    return (len(f"loc_{b.start:X}") + 6, 4)


def mk(edges: dict[int, list[tuple[int, str]]], n: int | None = None) -> list[G.Block]:
    ids = set(edges) | {d for v in edges.values() for d, _ in v}
    if n:
        ids |= set(range(n))
    return [G.Block(id=i, start=0x1000 + i * 0x10, end=0x1000 + i * 0x10 + 8,
                    succs=list(edges.get(i, []))) for i in sorted(ids)]


# ------------------------------------------------------------ invariants

def no_box_overlap(lay: G.Layout) -> bool:
    for i, a in enumerate(lay.nodes):
        for b in lay.nodes[i + 1:]:
            if (a.x <= b.right and b.x <= a.right
                    and a.y <= b.y + b.h - 1 and b.y <= a.y + a.h - 1):
                return False
    return True


def no_edge_through_box(lay: G.Layout) -> int:
    """Count edge cells landing strictly inside a box. Must be 0: this is the
    property the dummy-node machinery exists to guarantee."""
    bad = 0
    for row in range(lay.height):
        cells = lay.painting.cells_at_row(row, 0, lay.width)
        if not cells:
            continue
        for n in lay.nodes_at_row(row):
            for col in list(cells):
                if n.inside(row, col):
                    bad += 1
    return bad


def all_edges_drawn(lay: G.Layout) -> bool:
    """Every edge must contribute at least one painted cell."""
    seen = set()
    for row in range(lay.height):
        for _, (_, _, eid) in lay.painting.cells_at_row(row, 0, lay.width).items():
            seen.add(eid)
    return all(id(e) in seen for e in lay.edges)


def invariants(lay: G.Layout, name: str) -> None:
    check(no_box_overlap(lay), f"{name}: boxes must not overlap")
    check(no_edge_through_box(lay) == 0, f"{name}: no edge may cross a box")
    check(all(n.x >= 0 and n.y >= 0 for n in lay.nodes),
          f"{name}: no negative coordinates")
    check(lay.width > 0 and lay.height > 0, f"{name}: canvas has extent")


# ---------------------------------------------------------------- cases

def t_linear() -> None:
    lay = G.layout(mk({0: [(1, "uncond")], 1: [(2, "uncond")]}), sizer)
    invariants(lay, "linear")
    ranks = [lay.by_id[i].rank for i in (0, 1, 2)]
    check(ranks == [0, 1, 2], f"linear: ranks stack ({ranks})")
    check(all_edges_drawn(lay), "linear: every edge is drawn")


def t_diamond() -> None:
    lay = G.layout(mk({0: [(1, "jump"), (2, "fall")],
                       1: [(3, "uncond")], 2: [(3, "uncond")]}), sizer)
    invariants(lay, "diamond")
    check(lay.by_id[3].rank == 2, "diamond: join sits below both arms")
    check(lay.by_id[1].rank == lay.by_id[2].rank, "diamond: arms share a rank")
    check(len(lay.succ[0]) == 2, "diamond: entry has two successors")
    check(sorted(a for a, _ in lay.pred[3]) == [1, 2], "diamond: join has two preds")


def t_selfloop() -> None:
    """A self-loop must not stall the ranking — the bug that collapsed a whole
    function into three layers and made the graph 280 columns wide."""
    lay = G.layout(mk({0: [(1, "uncond")], 1: [(1, "jump"), (2, "fall")],
                       2: [(3, "uncond")]}), sizer)
    invariants(lay, "selfloop")
    ranks = [lay.by_id[i].rank for i in (0, 1, 2, 3)]
    check(ranks == [0, 1, 2, 3], f"selfloop: ranking still stacks ({ranks})")
    check(lay.by_id[1].block.selfloop, "selfloop: the block is marked")


def t_loop() -> None:
    lay = G.layout(mk({0: [(1, "uncond")], 1: [(2, "jump"), (3, "fall")],
                       2: [(1, "uncond")]}), sizer)
    invariants(lay, "loop")
    check(any(e.back for e in lay.edges), "loop: a back edge is detected")
    check(lay.by_id[1].rank < lay.by_id[2].rank, "loop: header above the body")
    back = [e for e in lay.edges if e.back][0]
    check((2, G.E_BACK) in [(a, s) for a, s in lay.pred[1]]
          or (1, G.E_BACK) in [(a, s) for a, s in lay.succ[2]],
          "loop: the back edge reads 2 -> 1 despite being reversed for layout")


def t_switch() -> None:
    lay = G.layout(mk({0: [(i, "switch") for i in range(1, 9)],
                       **{i: [(9, "uncond")] for i in range(1, 9)}}), sizer)
    invariants(lay, "switch")
    check(len({lay.by_id[i].rank for i in range(1, 9)}) == 1,
          "switch: all cases share a rank")
    check(lay.by_id[9].rank == 2, "switch: the join is below the cases")


def t_unreachable() -> None:
    """A block reachable only through a reversed edge must still get a rank."""
    lay = G.layout(mk({0: [(1, "uncond")], 2: [(2, "jump")]}, n=3), sizer)
    invariants(lay, "unreachable")
    check(len(lay.nodes) == 3, "unreachable: every block is placed")


def t_long_edge() -> None:
    """An edge spanning many layers gets dummies, so it reserves real space."""
    chain = {i: [(i + 1, "uncond")] for i in range(6)}
    chain[0] = [(1, "fall"), (6, "jump")]
    lay = G.layout(mk(chain), sizer)
    invariants(lay, "long_edge")
    check(lay.stats["dummies"] >= 4,
          f"long_edge: the skip edge is padded ({lay.stats['dummies']} dummies)")
    check(all_edges_drawn(lay), "long_edge: the long edge is drawn")


def t_empty() -> None:
    lay = G.layout([], sizer)
    check(lay.nodes == [], "empty: no nodes")
    check(lay.width >= 1 and lay.height >= 1, "empty: canvas is still sane")


def t_row_query() -> None:
    """cells_at_row must be windowed: asking for a slice returns only that
    slice, which is what keeps a 13M-cell graph renderable."""
    lay = G.layout(mk({0: [(1, "jump"), (2, "fall")],
                       1: [(3, "uncond")], 2: [(3, "uncond")]}), sizer)
    for row in range(lay.height):
        full = lay.painting.cells_at_row(row, 0, lay.width)
        part = lay.painting.cells_at_row(row, 5, 12)
        check(all(5 <= c < 12 for c in part), f"row {row}: window respected")
        check(all(full.get(c) == v for c, v in part.items()),
              f"row {row}: window agrees with the full row")


def t_hit_test() -> None:
    lay = G.layout(mk({0: [(1, "jump"), (2, "fall")]}), sizer)
    n = lay.nodes[0]
    check(lay.node_at(n.y, n.x) is n, "hit: top-left corner hits the node")
    check(lay.node_at(n.y + 1, n.x + 1) is n, "hit: interior hits the node")
    check(lay.node_at(n.y - 1, n.x) is None, "hit: above the node is empty")
    check(lay.node_at(n.y, n.right + 1) is None, "hit: right of the node is empty")


# ---------------------------------------------------------------- corpus

def t_corpus(path: str) -> None:
    recs = json.load(open(path))
    print(f"\ncorpus: {len(recs)} functions from {path}")
    worst_ms = 0.0
    worst_name = ""
    t0 = time.perf_counter()
    for rec in recs:
        blocks = [G.Block(id=b["id"], start=b["start"], end=b["end"],
                          succs=[(d, k) for d, k in b["succs"]])
                  for b in rec["blocks"]]
        lay = G.layout(blocks, sizer)
        if lay.stats["ms"] > worst_ms:
            worst_ms, worst_name = lay.stats["ms"], rec["name"]
        check(no_box_overlap(lay), f"corpus {rec['name']}: boxes must not overlap")
        check(len(lay.nodes) == len(blocks),
              f"corpus {rec['name']}: every block is placed")
        # The full cell sweep is O(canvas); only affordable on the small ones,
        # but that is where a routing bug would show up anyway.
        if lay.width * lay.height < 400_000:
            check(no_edge_through_box(lay) == 0,
                  f"corpus {rec['name']}: no edge may cross a box")
    total = (time.perf_counter() - t0) * 1000
    print(f"  laid out {len(recs)} functions in {total:.0f} ms "
          f"(worst {worst_ms:.0f} ms: {worst_name})")
    check(worst_ms < 2000, f"corpus: worst layout under 2s ({worst_ms:.0f} ms)")


def main() -> int:
    print("idatui.graph layout tests")
    for fn in (t_linear, t_diamond, t_selfloop, t_loop, t_switch,
               t_unreachable, t_long_edge, t_empty, t_row_query, t_hit_test):
        print(f"  {fn.__name__}")
        fn()
    for path in sys.argv[1:]:
        if os.path.exists(path):
            t_corpus(path)
    print(f"\n{CHECKS} checks, {len(FAILED)} failed")
    for f in FAILED:
        print(f"  - {f}")
    return 1 if FAILED else 0


if __name__ == "__main__":
    sys.exit(main())