#!/usr/bin/env python3
# Bundles the root *.lua (library + imgui_demo.lua), backends/ and fonts/ into ONE ModuleScript: build/ImGui.luau
# --no-demo: library only (imgui_demo.lua left out, like not compiling imgui_demo.cpp)
# Why: ModuleScripts don't share globals, and the setfenv() alternative turns off Luau's fast paths / native codegen.
# Each source file becomes a function in __FILES; IM_INCLUDE(name) runs it once and caches the result.
# The module returns a table with every global the library defines (ImGui, ImVec2, ImGuiConfigFlags, ImGui_ImplRoblox, ...).
import os, re

ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
import sys
NO_DEMO = "--no-demo" in sys.argv
sys.argv = [a for a in sys.argv if a != "--no-demo"]
FILES = {}
for d in (ROOT, os.path.join(ROOT, "backends"), os.path.join(ROOT, "fonts")):
    for f in sorted(os.listdir(d)):
        if f.endswith(".lua") and not (NO_DEMO and f == "imgui_demo.lua"):
            FILES[f] = open(os.path.join(d, f)).read()

ENTRY = ["imgui.lua", "imgui_impl_roblox.lua"] + ([] if NO_DEMO else ["imgui_demo.lua"])  # run order

names = set()
for src in FILES.values():
    names.update(re.findall(r"^function ([A-Za-z_]\w*)\s*\(", src, re.M))
    names.update(re.findall(r"^([A-Za-z_]\w*)\s*=[^=]", src, re.M))

out = ["--!optimize 2", "-- GENERATED by tools/bundle.py from *.lua, backends/, fonts/ - do not edit", "",
       "local __FILES, __LOADED = {}, {}",
       "function IM_INCLUDE(name)",
       "    local r = __LOADED[name]",
       "    if r == nil then r = __FILES[name](); if r == nil then r = true end; __LOADED[name] = r end",
       "    return r",
       "end", ""]
linemap = []  # (first bundle line, file) for error -> source mapping (tools/test/run.py)
for name, src in sorted(FILES.items()):
    out.append("__FILES[%r] = function()" % name)
    linemap.append((sum(x.count("\n") + 1 for x in out) + 1, name))
    out.append(src.rstrip("\n"))
    out.append("end")
    out.append("")
for name in ENTRY:
    out.append("IM_INCLUDE(%r)" % name)
out.append("")
out.append("return {")
for n in sorted(names):
    out.append("    %s = %s," % (n, n))
out.append("}")

import sys
OUT = sys.argv[1] if len(sys.argv) > 1 else os.path.join(ROOT, "build")
os.makedirs(OUT, exist_ok=True)
open(os.path.join(OUT, "ImGui.luau"), "w").write("\n".join(out) + "\n")
import json
json.dump(linemap, open(os.path.join(OUT, "ImGui.linemap.json"), "w"))
print("wrote build/ImGui.luau (%d files, %d exports)" % (len(FILES), len(names)))