// Five FRB (Five Runtime Binary) Demo
// Shows all FRB capabilities: file-based, in-memory compile, one-shot
// Copyright (c) 2026 Charles KWON OhJun (charleskwonohjun@gmail.com)
//
// Build: five build examples/frb_demo.prg -o frb_demo
// Prep:  five frb examples/frb_mathlib.prg -o mathlib.frb
// Run:   ./frb_demo

FUNCTION Main()

   ? "========================================="
   ? "  Five FRB (Five Runtime Binary) Demo"
   ? "========================================="
   ? ""

   // -----------------------------------------------
   // 1. Load pre-compiled FRB from file
   // -----------------------------------------------
   ? "--- 1. File-based FRB ---"
   ? ""
   LOCAL pMath := FrbLoad("mathlib.frb")
   IF pMath = NIL
      ? "  (skipped: mathlib.frb not found)"
      ? "  Build it: five frb examples/frb_mathlib.prg -o mathlib.frb"
   ELSE
      ? "  Loaded mathlib.frb"
      ? "  CircleArea(5.0)  =", FrbDo(pMath, "CIRCLEAREA", 5.0)
      ? "  Fibonacci(10)    =", FrbDo(pMath, "FIBONACCI", 10)
      ? "  IsPrime(97)      =", FrbDo(pMath, "ISPRIME", 97)
      FrbUnload(pMath)
      ? "  Unloaded."
   ENDIF
   ? ""

   // -----------------------------------------------
   // 2. Compile PRG source at runtime (in-memory)
   // -----------------------------------------------
   ? "--- 2. In-Memory Compilation ---"
   ? ""
   LOCAL cSource := ;
      'FUNCTION Reverse(cStr)' + Chr(10) + ;
      '   LOCAL i, cResult := ""' + Chr(10) + ;
      '   FOR i := Len(cStr) TO 1 STEP -1' + Chr(10) + ;
      '      cResult += SubStr(cStr, i, 1)' + Chr(10) + ;
      '   NEXT' + Chr(10) + ;
      '   RETURN cResult' + Chr(10) + ;
      'FUNCTION Repeat(cStr, n)' + Chr(10) + ;
      '   RETURN Replicate(cStr, n)' + Chr(10)

   ? "  Compiling PRG source at runtime..."
   LOCAL pStr := FrbCompile(cSource)
   IF pStr != NIL
      ? "  Reverse('Hello') =", FrbDo(pStr, "REVERSE", "Hello")
      ? "  Repeat('Go!', 3) =", FrbDo(pStr, "REPEAT", "Go!", 3)
      FrbUnload(pStr)
      ? "  Unloaded."
   ELSE
      ? "  ERROR: Compile failed"
   ENDIF
   ? ""

   // -----------------------------------------------
   // 3. One-shot: compile + run + unload
   // -----------------------------------------------
   ? "--- 3. One-Shot FrbExec ---"
   ? ""
   LOCAL cProgram := ;
      'FUNCTION Main()' + Chr(10) + ;
      '   LOCAL i, nSum := 0' + Chr(10) + ;
      '   FOR i := 1 TO 100' + Chr(10) + ;
      '      nSum += i' + Chr(10) + ;
      '   NEXT' + Chr(10) + ;
      '   RETURN nSum' + Chr(10)

   ? "  Sum of 1..100 =", FrbExec(cProgram)
   ? ""

   // -----------------------------------------------
   // 4. Dynamic code with goroutine
   // -----------------------------------------------
   ? "--- 4. Dynamic Code + Goroutine ---"
   ? ""
   LOCAL cAsync := ;
      'FUNCTION Worker(ch, n)' + Chr(10) + ;
      '   ChSend(ch, n * n)' + Chr(10) + ;
      '   RETURN NIL' + Chr(10)

   LOCAL pAsync := FrbCompile(cAsync)
   IF pAsync != NIL
      LOCAL ch := Channel(1)
      Go("WORKER", ch, 7)
      ? "  7^2 from dynamic goroutine =", ChReceive(ch)
      FrbUnload(pAsync)
   ENDIF
   ? ""

   ? "========================================="
   ? "  Done! PRG code compiled at runtime"
   ? "  and executed at native Go speed."
   ? "========================================="

   RETURN NIL