#!/usr/bin/env python3
"""migrate-columns — move each orbit's effect knobs into that orbit's column.

The other half of #46. See tools/surface-columns.py for the survey that prices
the work and explains the grid; this tool performs it.

THE TARGET GRID (settled with PLN 2026-07-29)

      col        1       2       3       4       5       6       7       8
  A 13-20    d9 lvl  d10 lvl d11 lvl d12 lvl d9 fx   d10 fx  d11 fx  d12 fx
  B 29-36    d1 fx   d2 fx   d3 fx   d4 fx   d5 fx   d6 fx   d7 fx   d8 fx
  C 49-56    gF1     gF2     gF3     d4 fx2  d5 fx2  d6 fx2  d7 fx2  d8 fx2
  D 77-84    d1 lvl  d2 lvl  d3 lvl  d4 lvl  d5 lvl  d6 lvl  d7 lvl  d8 lvl

So each of d1-d8 gets its FADER for level and its B knob for one effect;
d4-d8 also get their C knob for a second. d1-d3 do NOT, because C1/C2/C3 are
the three family DJ filters (gF1 drums, gF2 bass, gF3 leads) — measured to be
applied per-FAMILY across the whole corpus, and deliberately left alone.

WHAT THIS TOOL WILL NOT TOUCH

  * faders 77-84 and knobs 13-16 — MIDI-learned to Ardour track gains. Writing
    or renumbering into that range is the CC77-goes-to-silence footgun.
  * the 8 helper CCs (gF1-3, gMask, gMute1-3, gPanic) — BootTidal owns them.
  * buttons (41-44, 57-60, 73-76, 89-92) — gates and mutes are a separate axis
    with their own collisions against gMask/gMute, and retraining a gate is more
    disruptive than retraining a knob. Phase 2, after the gig.

WHY THE PERMUTATION MUST BE APPLIED SIMULTANEOUSLY

Computing the moves one at a time makes the corpus look like a minefield: 34
"destination already taken" clashes. They are phantom. The corpus is uniformly
off by one column, so each orbit's knob wants the slot of the orbit below it,
which is occupied *only until that one also moves*. Build the whole map, then
rewrite in a single pass, and the clashes vanish. Applying moves sequentially
would corrupt the file.

WHY THE REWRITE IS SCOPED PER ORBIT

Two orbits can legitimately share a CC today (desire.tidal had ^19 driving both
d7 and d9) and they migrate to DIFFERENT destinations. A file-wide
search-and-replace would send both to the same place and silently merge two
gestures into one. So the substitution walks orbit by orbit, applying only that
orbit's own map to that orbit's own lines.

OVERFLOW -> gSel

An orbit with three or more knobs has more effects than the grid has slots.
Those are NOT renumbered into a neighbour's column; they are left in place with
a FIXME(#54) pointing at gSel, the clamped knob-selector that folds a multi-knob
stack onto one control. PLN: "if we have two effects, we consolidate via gSel
indeed. mark FIXMEs in code in there".

Usage:
    tools/migrate-columns.py --plan  TRACK [...]    # show, change nothing
    tools/migrate-columns.py --apply TRACK [...]    # rewrite in place
    tools/migrate-columns.py --plan                 # whole OPAL setlist

Always --plan first. Always pvlint + silent-eval after --apply.
"""
from __future__ import annotations

import argparse
import re
import sys
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parent))
from pvlint.core import load, strip_comment  # noqa: E402

ROOT = Path(__file__).resolve().parent.parent
SETLIST = ROOT / "armada" / "setlist_opal2026.txt"

CC_REF = re.compile(r'"\^(\d+)"')

KNOB_A = set(range(13, 21))
KNOB_B = set(range(29, 37))
KNOB_C = set(range(49, 57))
KNOBS = KNOB_A | KNOB_B | KNOB_C
# Hands off, for the reasons in the docstring.
ARDOUR = set(range(77, 85)) | {13, 14, 15, 16}
BUTTONS = set(range(41, 45)) | set(range(57, 61)) | set(range(73, 77)) | set(range(89, 93))


def helper_ccs() -> set[int]:
    """CCs BootTidal's helpers own. Comment-stripped — see surface-columns."""
    boot = ROOT / "BootTidal.hs"
    if not boot.exists():
        return set()
    text = boot.read_text()
    i = text.find("let -- DPV specific parameters")
    if i >= 0:
        j = text.find("\n:}", i)
        text = text[i:j if j > 0 else len(text)]
    text = "\n".join(strip_comment(l) for l in text.splitlines())
    return {int(m) for m in CC_REF.findall(text)}


def label(cc: int) -> str:
    """'^35' -> 'B7'. The one place CC->physical-control naming lives here."""
    for base, row in ((12, "A"), (28, "B"), (48, "C"),
                      (40, "BT"), (52, "BT"), (72, "BL"), (84, "BL")):
        col = cc - base
        if 1 <= col <= 8:
            if row == "BT" and not (41 <= cc <= 44 or 57 <= cc <= 60):
                continue
            if row == "BL" and not (73 <= cc <= 76 or 89 <= cc <= 92):
                continue
            if row in ("A", "B", "C") and col > 8:
                continue
            return f"{row}{col}"
    return f"cc{cc}"


def knob_slots(orbit: int) -> list[int]:
    """The knob destinations an orbit owns, in order of reachability.

    B<col> first (row B is per-orbit for all 8 columns), then C<col> — but C1/C2/C3
    are gF1/gF2/gF3, the per-FAMILY DJ filters, so d1..d3 own exactly one knob.
    """
    slots = [28 + orbit]
    if orbit >= 4:
        slots.append(48 + orbit)
    return slots


def button_slots(orbit: int) -> list[int]:
    """The button destinations an orbit owns, in order of reachability.

    BT (top button row) is per-orbit across all 8 columns: 41-44 then 57-60.
    BL (bottom row) columns 1-3 are gMute1/gMute2/gMute3, the per-family mutes,
    so d1..d3 own exactly ONE button. That is the structural reason a two-button
    gesture on d1 cannot survive column alignment — see the clash report.
    """
    slots = [40 + orbit if orbit <= 4 else 52 + orbit]        # 41..44, 57..60
    if orbit >= 4:
        slots.append(72 + orbit if orbit <= 4 else 84 + orbit)  # 76, 89..92
    return slots


def _seen_ccs(blocks: list, pool: set[int], helpers: set[int]) -> list[tuple[int, int]]:
    """CCs of one kind an orbit drives, in first-appearance order.

    Takes ALL BLOCKS of that orbit, not one. A track routinely declares the same
    orbit several times as section alternates — perfect.tidal has six `d1 $ …`
    blocks. Planning per block and keying by orbit number silently dropped every
    block but the last, which is why perfect.tidal kept ^42 on d1 while d2 also
    owned ^42: d1's move was computed and then overwritten. An orbit's control
    set is the UNION across its blocks.

    First-appearance order matters: the first control written is the one most
    likely to be the primary gesture, so it gets the most reachable slot.
    """
    seen: list[tuple[int, int]] = []
    for orb in blocks:
        for off, raw in enumerate(orb.lines):
            for m in CC_REF.finditer(strip_comment(raw)):
                cc = int(m.group(1))
                if cc in pool and cc not in helpers and cc not in ARDOUR:
                    if cc not in [c for c, _ in seen]:
                        seen.append((cc, orb.start + off))
    return seen


def segment(lines: list[str], i: int, last: int) -> list[int]:
    """The whole `$`-chain segment starting at 1-indexed line i.

    Commenting out a single LINE is wrong, and it produced a parse error the
    first time: a Tidal chain step routinely spans several lines —

        $ midiOn ("^53" - "^18") (        <- comment only this
          slice 4 "<0 1 0 1 2 2 [2 2] 3>"   and the body stays live
          )                                 and this ) is orphaned

    In this codebase a chain step starts with `$` or `#` (or `d<N>` for a new
    orbit), so the segment runs from i up to just before the next such line.
    Verified afterwards by paren balance: if the segment does not close, we
    refuse rather than write syntactically broken Haskell.
    """
    out = [i]
    j = i + 1
    while j <= last:
        s = lines[j - 1].strip()
        if not s or re.match(r"(\$|#|d\d+\b|let\b|--\s*(FIXME|TODO))", s):
            break
        out.append(j)
        j += 1
    depth = 0
    for k in out:
        code = strip_comment(lines[k - 1])
        code = re.sub(r'"[^"]*"', '""', code)      # parens inside strings don't count
        depth += code.count("(") - code.count(")")
        depth += code.count("[") - code.count("]")
    if depth != 0:
        raise SystemExit(
            f"migrate-columns: segment at line {i} does not close (depth {depth}); "
            f"refusing to comment it out — this would produce broken Haskell.")
    return out


def plan_track(path: Path, helpers: set[int]) -> dict:
    """Per-orbit {src cc -> dest cc}, plus overflow and cross-orbit clashes."""
    track = load(path)
    blocks: dict[int, list] = {}
    for o in track.orbits():
        if 1 <= o.number <= 8:
            blocks.setdefault(o.number, []).append(o)

    # Pass 1: what each orbit WANTS, planned over ALL of that orbit's blocks.
    wants: dict[int, list[tuple[int, int, int]]] = {}   # orbit -> [(cc,line,dest)]
    overflow: list[tuple[int, int, int]] = []           # (orbit, cc, line)
    for number, orbs in blocks.items():
        pairs: list[tuple[int, int, int]] = []
        for pool, slots in ((KNOBS, knob_slots(number)),
                            (BUTTONS, button_slots(number))):
            for i, (cc, line) in enumerate(_seen_ccs(orbs, pool, helpers)):
                if i < len(slots):
                    pairs.append((cc, line, slots[i]))
                else:
                    overflow.append((number, cc, line))
        wants[number] = pairs

    # Pass 2: a destination is only free if NO overflow CC is squatting it. An
    # overflow CC does not move, so moving another orbit onto it would put two
    # orbits on one physical control — the failure this guard exists to prevent.
    # OVERFLOW IS COMMENTED OUT, NOT LEFT IN PLACE — so it does NOT squat.
    #
    # The first version left an over-budget control where it was. That looks
    # conservative and is actually a bug generator: once ^42 becomes d2's button,
    # any d1 line still referencing ^42 means pressing d2's gate also fires d1's
    # kick variant. Measured on the real setlist, that is exactly what happened:
    # perfect.tidal ended up with ^42 driving BOTH d1 and d2.
    #
    # It was also a cascade: d1's stuck ^42 blocked d2, which blocked d3, which
    # blocked d4, which blocked d5 — bombe_dj could only reach 4/8 aligned. PLN:
    # "we need finish the job. why half moved? cant you move all-but then comment
    # out with fixme?" Commenting the line out frees the control, so the rest of
    # the row aligns, and nothing is lost: the original is one line above under
    # two dashes, re-enableable the moment gSel (#54) can fold it onto one knob.
    #
    # A clashed control still stays put, so it IS sticky, and discovering a clash
    # changes the answer for orbits already processed. Hence the fixed point.
    base_sticky: set[int] = set()
    sticky = set(base_sticky)
    per_orbit: dict[int, dict[int, int]] = {}
    clashes: list[tuple[int, int, int, int, str]] = []
    for _round in range(len(wants) + 2):
        per_orbit, clashes = {}, []
        claimed: dict[int, int] = {}                     # dest -> orbit
        for orbit, pairs in wants.items():
            m: dict[int, int] = {}
            for cc, line, dest in pairs:
                if dest == cc:
                    claimed[dest] = orbit                # already home
                    continue
                if dest in sticky:
                    clashes.append((orbit, cc, line, dest,
                                    f"^{dest} is held by a control that cannot move"))
                elif dest in claimed and claimed[dest] != orbit:
                    clashes.append((orbit, cc, line, dest,
                                    f"^{dest} already claimed by d{claimed[dest]}"))
                else:
                    m[cc] = dest
                    claimed[dest] = orbit
            # Guard: within one orbit two sources must never share a destination.
            if len(set(m.values())) != len(m):
                raise SystemExit(f"migrate-columns: internal collision in "
                                 f"{path.name} d{orbit}: {m}")
            per_orbit[orbit] = m
        grown = base_sticky | {cc for _o, cc, _l, _d, _w in clashes}
        if grown == sticky:
            break
        sticky = grown
    else:
        raise SystemExit(f"migrate-columns: {path.name} did not converge — "
                         f"report this, do not --apply")
    return dict(track=track, per_orbit=per_orbit,
                overflow=overflow, clashes=clashes)


def rewrite(path: Path, res: dict) -> tuple[int, list[str]]:
    """Apply the plan. Returns (substitutions made, notes)."""
    lines = path.read_text().splitlines(keepends=True)
    # line number (1-indexed) -> that orbit's map
    line_map: dict[int, dict[int, int]] = {}
    for orb in res["track"].orbits():
        m = res["per_orbit"].get(orb.number)
        if not m:
            continue
        for off in range(len(orb.lines)):
            line_map[orb.start + off] = m

    n = 0
    for idx in range(len(lines)):
        m = line_map.get(idx + 1)
        if not m:
            continue
        code_end = len(lines[idx])
        # Only rewrite live code, never a comment: a commented-out ^NN is an
        # ALTERNATIVE PLN may re-enable, and renumbering it would silently
        # rewire that alternative to a different orbit's knob.
        c = lines[idx].find("--")
        if c >= 0:
            code_end = c

        def sub(mo, _m=m):
            nonlocal n
            cc = int(mo.group(1))
            if mo.start() >= code_end or cc not in _m or _m[cc] == cc:
                return mo.group(0)
            n += 1
            return f'"^{_m[cc]}"'

        lines[idx] = CC_REF.sub(sub, lines[idx])

    notes = []
    # Overflow: COMMENT OUT every live line of that orbit which references the
    # over-budget control, and head the group with one FIXME. Every such line
    # must go, not just the ones mentioning the control alone — the control now
    # belongs to a DIFFERENT orbit, so any surviving reference is a cross-orbit
    # trigger (the perfect.tidal ^42-drives-d1-and-d2 bug).
    #
    # Clashes: annotate only. A clashed control keeps its own CC, so it is still
    # correct code; it is simply not where the grid wants it.
    edits: list[tuple[int, str, list[int], str]] = []   # (anchor, fixme, lines, note)
    # ALL blocks of each orbit, not just the last — see _seen_ccs.
    ranges: dict[int, list[tuple[int, int]]] = {}
    for o in res["track"].orbits():
        ranges.setdefault(o.number, []).append((o.start, o.start + len(o.lines) - 1))
    for orbit, cc, line in res["overflow"]:
        hits: set[int] = set()
        for start, end in ranges.get(orbit, [(line, line)]):
            for i in range(start, min(end, len(lines)) + 1):
                if (not lines[i - 1].lstrip().startswith("--")
                        and f'"^{cc}"' in strip_comment(lines[i - 1])):
                    # Expand to the whole chain segment, or the closing parens of
                    # a multi-line step are left dangling.
                    hits.update(segment(lines, i, end))
        hits = sorted(hits) if hits else [line]
        slots = (f"BT{orbit}" + (f" + BL{orbit}" if orbit >= 4
                                 else " only — BL1-3 are the family mutes")
                 if cc in BUTTONS
                 else f"B{orbit}" + (f" + C{orbit}" if orbit >= 4
                                     else " only (C1-3 are the family gF filters)"))
        tag = "#94" if cc in BUTTONS else "#54"
        fixme = (f"-- FIXME({tag}) d{orbit} drives more controls than the grid gives it "
                 f"({slots}). ^{cc} now belongs to another orbit, so the line(s) below "
                 f"are COMMENTED OUT rather than left firing across columns. Nothing is "
                 f"lost — restore by removing the dashes once gSel folds this onto "
                 f"d{orbit}'s own control.")
        edits.append((hits[0], fixme, hits, f"d{orbit} ^{cc} commented out ({len(hits)} line(s))"))
    for orbit, cc, line, dest, reason in res.get("clashes", []):
        edits.append((line,
                      f"-- FIXME(#94) d{orbit}: ^{cc} should become ^{dest} ({label(dest)}) "
                      f"but {reason}. Left on ^{cc} — moving it would put two orbits on "
                      f"one physical control.",
                      [], f"d{orbit} ^{cc} CLASH -> ^{dest} at line {line}"))

    # Bottom-up so earlier line numbers stay valid as we insert.
    for anchor, fixme, hits, note in sorted(edits, key=lambda e: e[0], reverse=True):
        for i in sorted(hits, reverse=True):
            stripped = lines[i - 1].rstrip("\n")
            indent = stripped[: len(stripped) - len(stripped.lstrip())]
            nl = "\n" if lines[i - 1].endswith("\n") else ""
            lines[i - 1] = f"{indent}-- {stripped.lstrip()}{nl}"
        indent = re.match(r"\s*", lines[anchor - 1]).group(0)
        lines.insert(anchor - 1, f"{indent}{fixme}\n")
        notes.append(note)
    path.write_text("".join(lines))
    return n, notes


def resolve(names: list[str]) -> list[Path]:
    if not names:
        names = [l.strip() for l in SETLIST.read_text().splitlines()
                 if l.strip() and not l.startswith("#")]
    out = []
    for nm in names:
        p = Path(nm)
        if p.exists():
            out.append(p); continue
        hits = sorted(ROOT.glob(f"live/**/{Path(nm).stem}.tidal"))
        if hits:
            out.append(hits[0])
        else:
            print(f"  ?? no .tidal for {nm}", file=sys.stderr)
    return out


def main() -> int:
    ap = argparse.ArgumentParser(description=__doc__,
                                 formatter_class=argparse.RawDescriptionHelpFormatter)
    ap.add_argument("tracks", nargs="*")
    g = ap.add_mutually_exclusive_group(required=True)
    g.add_argument("--plan", action="store_true")
    g.add_argument("--apply", action="store_true")
    ap.add_argument("--force-partial", action="store_true",
                    help="apply even to a track with clashes (leaves it HALF aligned)")
    a = ap.parse_args()

    helpers = helper_ccs()
    total_moves = total_over = total_clash = 0
    for p in resolve(a.tracks):
        res = plan_track(p, helpers)
        moves = [(s, d, o) for o, m in res["per_orbit"].items()
                 for s, d in m.items() if s != d]
        keeps = sum(1 for m in res["per_orbit"].values()
                    for s, d in m.items() if s == d)
        print(f"== {p.name}   {len(moves)} move  {keeps} keep  "
              f"{len(res['overflow'])} overflow  {len(res['clashes'])} clash")
        for s, d, o in sorted(moves, key=lambda x: x[2]):
            kind = "btn " if s in BUTTONS else "knob"
            print(f"     d{o:<2} {kind} ^{s:<3} {label(s):<4}  ->  ^{d:<3} {label(d)}")
        for o, cc, line in res["overflow"]:
            print(f"     d{o:<2} ^{cc:<3} {label(cc):<4} line {line}  -> FIXME (no slot)")
        for o, cc, line, dest, reason in res["clashes"]:
            print(f"     d{o:<2} ^{cc:<3} {label(cc):<4} line {line}  -> CLASH: {reason}")
        total_moves += len(moves); total_over += len(res["overflow"])
        total_clash += len(res["clashes"])
        if a.apply and res["clashes"] and not a.force_partial:
            # A track with clashes cannot be FULLY aligned, and applying only the
            # movable half is the worst outcome for muscle memory: the player
            # then has to remember which orbits moved and which did not. A
            # consistently-old track beats an inconsistently-new one. Skip it,
            # name it, and let the blocking decision be made deliberately.
            print(f"     SKIPPED — {len(res['clashes'])} clash(es); this track cannot be "
                  f"fully aligned. Resolve the blocking gesture first, or "
                  f"--force-partial to half-migrate it on purpose.")
            continue
        if a.apply:
            n, notes = rewrite(p, res)
            print(f"     APPLIED: {n} substitution(s), {len(notes)} FIXME(s)")
    print(f"\n  {total_moves} move(s), {total_over} overflow -> gSel")
    if a.apply:
        print("  NOW RUN: cd tools && python3 -m pvlint ...   then  "
              "tools/silent-eval.py --seeded ...")
    return 0


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