#!/usr/bin/env bash
set -euo pipefail

ROOT_DIR="$PWD"

if [ -d "$ROOT_DIR/MG5_aMC_v2_9_27" ]; then
    echo "[skip] MG5_aMC_v2_9_27 already exists -> skipping download"
else
    wget https://launchpad.net/mg5amcnlo/lts/2.9.x/+download/MG5_aMC_v2.9.27.tar.gz
    tar -axvf MG5_aMC_v2.9.27.tar.gz
    rm MG5_aMC_v2.9.27.tar.gz
fi
cd "$ROOT_DIR/MG5_aMC_v2_9_27/models"

if [ -d "SMEFTsim_topU3l_MwScheme_UFO" ]; then
    echo "[skip] SMEFTsim_topU3l_MwScheme_UFO already exists -> skipping clone"
else
    rm -rf SMEFTsim
    git clone git@github.com:SMEFTsim/SMEFTsim.git
    mv SMEFTsim/UFO_models/SMEFTsim_topU3l_MwScheme_UFO .
    rm -rf SMEFTsim
fi
cd SMEFTsim_topU3l_MwScheme_UFO/

BASE="restrict_SMlimit_massless.dat"
COEFF="cHWB"
# The trick: this must be a generic, non-special value -- NOT exactly 0 or 1.
# MG5 hardcodes/prunes a parameter restricted to 0 or 1 (dropping its Block
# SMEFT entry from param_card.dat), but leaves any other value -- like this
# one -- external/settable. create.sh depends on that: it reuses this same
# restriction card for PROC_cHWB_NP1, whose reweight_card.dat needs cHWB to
# still be a settable parameter.
VALUE="9.999999e-01"
OUT="restrict_${COEFF}_massless.dat"

if [ -f "$OUT" ]; then
    echo "[skip] $OUT already exists"
else
    sed -E "s/^(.*)0\.000000e\+00( # ${COEFF}[[:space:]]*)\$/\1${VALUE}\2/" \
        "$BASE" > "$OUT"
fi


# ---------------------------------------------------------------------------
# Portability fix: MG5's f2py toolchain. Local only -- no downloads, no
# execution of remote code. Safe to rerun.
#
# MG5's "f2py_compiler_py3" config option can only ever hold a single
# executable token: do_set() in madgraph/interface/common_run_interface.py
# tokenizes the config line on whitespace and keeps only args[1], and
# misc.which() can't resolve a value containing spaces either way -- so a
# multi-word command like "python3 -m numpy.f2py" can never be set directly.
# On macOS specifically, Homebrew's f2py/f2py3/f2py3.10/f2py3.11 binaries are
# commonly stale symlinks into an old numpy Cellar path whose shebang points
# at a python3.x Homebrew has since removed -> compile fails with "f2py: No
# such file or directory".
#
# Fix: generate a single-token wrapper script around a python3 this script
# has actually verified has a working numpy.f2py, and point MG5's config at
# that wrapper instead of the real (multi-word) command.
MG5_DIR="$ROOT_DIR/MG5_aMC_v2_9_27"

echo "==> Looking for a working python3 + numpy.f2py ..."
PYTHON3=""
for CAND in python3 /usr/bin/python3 /opt/homebrew/bin/python3 /usr/local/bin/python3 \
            python3.13 python3.12 python3.11 python3.10 python3.9; do
    command -v "$CAND" >/dev/null 2>&1 || continue
    RESOLVED="$(command -v "$CAND")"
    if "$RESOLVED" -c "import numpy.f2py" >/dev/null 2>&1; then
        PYTHON3="$RESOLVED"
        break
    fi
done

if [ -z "$PYTHON3" ]; then
    echo "ERROR: no python3 on PATH has a working numpy.f2py module." >&2
    echo "       fix with, e.g.: python3 -m pip install --user numpy" >&2
    exit 1
fi
NUMPY_VER="$("$PYTHON3" -c 'import numpy; print(numpy.__version__)')"
echo "    using $PYTHON3 (numpy $NUMPY_VER)"

WRAPPER="$MG5_DIR/f2py_wrapper.sh"
cat > "$WRAPPER" <<WRAPEOF
#!/usr/bin/env bash
# Auto-generated by setup.sh -- do not edit by hand, rerun setup.sh instead.
exec "$PYTHON3" -m numpy.f2py "\$@"
WRAPEOF
chmod +x "$WRAPPER"
echo "==> Wrote $WRAPPER"

echo "==> Checking compilers ..."
HAVE_FORTRAN=1
check_tool() {
    local tool="$1" hint="$2"
    if command -v "$tool" >/dev/null 2>&1; then
        echo "    OK      $tool -> $(command -v "$tool")"
    else
        echo "    MISSING $tool -- install with: $hint"
        if [ "$tool" = "gfortran" ]; then HAVE_FORTRAN=0; fi
    fi
}
case "$(uname -s)" in
    Darwin) check_tool gfortran "brew install gcc"; check_tool clang "xcode-select --install" ;;
    Linux)  check_tool gfortran "sudo apt-get install gfortran"; check_tool g++ "sudo apt-get install g++" ;;
    *)      check_tool gfortran "install a Fortran compiler"; check_tool g++ "install a C++ compiler" ;;
esac

if [ "$HAVE_FORTRAN" = "1" ]; then
    echo "==> Smoke-testing f2py wrapper ..."
    TMPD="$(mktemp -d)"
    trap 'rm -rf "$TMPD"' EXIT
    cat > "$TMPD/hello.f" <<'FORTRAN_EOF'
      subroutine hello(x, y)
      real*8 x, y
Cf2py intent(in) x
Cf2py intent(out) y
      y = x * 2.0d0
      end
FORTRAN_EOF
    if ( cd "$TMPD" && "$WRAPPER" -c -m hello hello.f ) >"$TMPD/f2py.log" 2>&1; then
        echo "    OK: wrapper compiles Fortran extensions."
    else
        echo "ERROR: f2py smoke test failed:" >&2
        cat "$TMPD/f2py.log" >&2
        exit 1
    fi
else
    echo "==> Skipping f2py smoke test (no gfortran) -- install it, then rerun setup.sh."
fi

# Generic "set key = value in this mg5_configuration.txt" helper -- strips
# any existing (commented-out or live) line for that key and appends the new
# value, so reruns are idempotent no matter what state the file was in.
# Shared below by both the f2py_compiler_py3 patch and the lhapdf patch.
patch_config() {
    local cfg="$1" key="$2" value="$3"
    [ -f "$cfg" ] || return 0
    if grep -qF "$key = $value" "$cfg" 2>/dev/null; then
        echo "[skip] $cfg already points $key at $value"; return 0
    fi
    local tmp="$cfg.tmp.$$"
    grep -v -E "^#?[[:space:]]*${key}[[:space:]]*=" "$cfg" > "$tmp"
    printf '%s = %s\n' "$key" "$value" >> "$tmp"
    mv "$tmp" "$cfg"
    echo "==> Patched $cfg ($key)"
}

# Only the master template + user-level override -- deliberately NOT touching
# any already-generated PROC_*/ output, since those may belong to a run of
# create.sh that's still in flight.
patch_config "$MG5_DIR/input/mg5_configuration.txt" "f2py_compiler_py3" "$WRAPPER"
patch_config "$HOME/.mg5/mg5_configuration.txt" "f2py_compiler_py3" "$WRAPPER"

echo "==> f2py toolchain fix complete."

# ---------------------------------------------------------------------------
# LHAPDF6 install, via MG5's own "install lhapdf6" command. Local compile,
# one network fetch of source -- reproducible, idempotent, safe to rerun.
#
# Why via MG5's installer and not e.g. Homebrew: the systematics module
# (QCD scale + PDF uncertainty reweighting, madgraph/various/systematics.py)
# does `import lhapdf` *inside whatever python3 process is already running
# MG5* -- madgraph/various/misc.py's import_python_lhapdf() does the import
# in-process, not via a subprocess (verified by reading it). A compiled
# lhapdf python extension is ABI-locked to the exact python3 minor version
# it was built against. Installing LHAPDF6 via Homebrew would build it
# against Homebrew's own python (currently python@3.10 here) while MG5 runs
# under whatever `env python3` resolves to (the system python3 on this
# machine) -- a cross-interpreter mismatch that would leave `import lhapdf`
# failing even with a perfectly good install. MG5's own "install lhapdf6"
# instead builds LHAPDF6's python bindings against the exact python3
# already running MG5 at install time, sidestepping the ABI problem
# entirely -- and it's the officially-supported path (madgraph_interface.py
# even offers it interactively when e.g. installing pythia8's lhapdf
# dependency). Since create.sh invokes MG5's bin/* scripts the same way
# (`env python3`), the interpreter at install time and at run time matches.
#
# This does need network access once, to fetch LHAPDF6's source and MG5's
# HEPToolsInstaller manifest from MG5's own package servers, then compiles
# LHAPDF6 from source (C++, a few minutes) -- there's no vendored/offline
# tarball for it under MG5_aMC_v2_9_27/vendor/ (unlike CutTools/StdHEP/etc,
# which do ship offline copies).
LHAPDF_CONFIG="$MG5_DIR/HEPTools/lhapdf6_py3/bin/lhapdf-config"
if [ -x "$LHAPDF_CONFIG" ]; then
    echo "[skip] $LHAPDF_CONFIG already exists -> skipping LHAPDF6 install"
else
    echo "==> Installing LHAPDF6 via MG5's own installer (compiles from source, can take several minutes) ..."
    INSTALL_CMD="$(mktemp "${TMPDIR:-/tmp}/install_lhapdf6.XXXXXX")"
    printf 'install lhapdf6\n' > "$INSTALL_CMD"

    # LHAPDF's own ./configure auto-detects where to install its python
    # bindings by asking the running python3's sysconfig for its "platlib"
    # scheme dir. On this machine python3 resolves to Xcode's bundled
    # framework python (sys.executable lands under
    # /Applications/Xcode.app/.../Python3.framework/...), whose sysconfig
    # reports the *system*, root-owned /Library/Python/3.X/site-packages --
    # so an unprivileged `make install` fails there with "Permission
    # denied" partway through (the C++ library/lhapdf-config/PDF-set
    # machinery all install fine; only this last step needs root, verified
    # by hitting exactly this failure on a first attempt here).
    # LHAPDF's configure.ac explicitly supports overriding this via the
    # LHAPDF_PYTHONPATH env variable (its own notice says so: "override
    # with LHAPDF_PYTHONPATH env variable") -- point it at a directory
    # *inside* our own install prefix instead. This isn't just a
    # workaround: it's exactly the layout MG5's own madgraph/various/
    # misc.py import_python_lhapdf() already knows how to find on its own
    # (it scans <lhapdf-config --libdir>/*/site-packages), so no further
    # wiring is needed for MG5 to pick it up at runtime. Scoped to a
    # subshell so it doesn't leak into the rest of this script.
    PYVER="$(python3 -c 'import sys; print("%d.%d" % sys.version_info[:2])')"
    LHAPDF_INSTALL_DIR="$MG5_DIR/HEPTools/lhapdf6_py3"
    (
        export LHAPDF_PYTHONPATH="$LHAPDF_INSTALL_DIR/lib/python$PYVER/site-packages"
        "$MG5_DIR/bin/mg5_aMC" "$INSTALL_CMD"
    )
    rm -f "$INSTALL_CMD"

    if [ ! -x "$LHAPDF_CONFIG" ]; then
        echo "ERROR: LHAPDF6 install finished but $LHAPDF_CONFIG is missing." >&2
        echo "       Check the mg5_aMC output above for the actual failure." >&2
        exit 1
    fi
fi
echo "    using $("$LHAPDF_CONFIG" --version 2>&1) at $LHAPDF_CONFIG"

# Belt-and-braces: MG5's own "install lhapdf6" already persists this path
# under the *lhapdf_py3* key (via its internal `save options ... lhapdf_py3`
# call), but madevent's `systematics` command (do_systematics(), in
# madgraph/interface/common_run_interface.py) reads the *lhapdf* key -- no
# _py3 suffix -- which is only ever set in-memory during the install session
# itself and never written back to mg5_configuration.txt. Patch it in
# ourselves, same mechanism as f2py_compiler_py3 above, so a *fresh* MG5
# process (like the ones create.sh launches later for event generation and
# systematics) resolves it too, not just the one running this install.
patch_config "$MG5_DIR/input/mg5_configuration.txt" "lhapdf" "$LHAPDF_CONFIG"
patch_config "$HOME/.mg5/mg5_configuration.txt" "lhapdf" "$LHAPDF_CONFIG"

echo "==> LHAPDF6 install complete."