// Selfhost Compiler MVP (Phase 15.3)
// Reads tmp/ny_parser_input.ny and prints a minimal JSON v0 program.
// Components are split under boxes/ and included here.

// Prefer using for module declaration (Runner strips and registers)
using "apps/selfhost-compiler/boxes/debug_box.nyash" as DebugBoxMod
using "apps/selfhost-compiler/boxes/parser_box.nyash" as ParserBoxMod
using "apps/selfhost-compiler/boxes/emitter_box.nyash" as EmitterBoxMod
using "apps/selfhost-compiler/boxes/mir_emitter_box.nyash" as MirEmitterBoxMod

// (removed) Transitional duplicate using lines to avoid resolver duplicate-import error

static box Main {
  // ---- IO helper ----
  read_all(path) {
    local fb = new FileBox()
    fb.open(path, "r")
    local s = fb.read()
    fb.close()
    if s == null { return "return 1+2*3" }
    return s
  }

  // ---- JSON helpers ----
  esc_json(s) {
    local out = ""
    local i = 0
    local n = s.length()
    loop(i < n) {
      local ch = s.substring(i, i+1)
      if ch == "\\" { out = out + "\\\\" } else {
        if ch == "\"" { out = out + "\\\"" } else { out = out + ch }
      }
      i = i + 1
    }
    return out
  }

  // Parser delegation
  parse_program(src, stage3_flag) {
    local parser = new ParserBox()
    if stage3_flag == 1 { parser.stage3_enable(1) }
    // Collect using metadata (no-op acceptance in Stage‑15)
    parser.extract_usings(src)
    me._usings = parser.get_usings_json()
    return parser.parse_program2(src)
  }

  main(args) {
    // Debug setup
    me.dbg = new DebugBox()
    me.dbg.set_enabled(0)

    // Source selection (EXE-first friendly)
    // - default: safe constant
    // - positional arg: treat as input file path
    // - --read-tmp: use tmp/ny_parser_input.ny (requires FileBox plugin)
    local src = "return 1+2*3"
    local read_tmp = 0
    local input_path = null
    local stage3_mode = 0
    if args != null {
      local alen = args.length()
      local i = 0
      loop(i < alen) {
        local a = args.get(i)
        if a == "--read-tmp" {
          read_tmp = 1
        } else {
          if a == "--min-json" {
            /* handled later */
          } else {
            if a == "--stage3" {
              stage3_mode = 1
            } else {
              if input_path == null { input_path = a }
            }
          }
        }
        i = i + 1
      }
    }
    if input_path != null {
      // Prefer explicit file when provided (requires FileBox plugin)
      local s1 = me.read_all(input_path)
      if s1 != null { src = s1 }
    } else {
      if read_tmp == 1 {
        // Optional: read tmp/ny_parser_input.ny (requires FileBox plugin; do not use in CI)
        local s2 = me.read_all("tmp/ny_parser_input.ny")
        if s2 != null { src = s2 }
      }
    }

    // Gate: minimal JSON when requested via script arg
    local min_mode = 0
    local emit_mir = 0
    if args != null {
      local alen = args.length()
      local i = 0
      loop(i < alen) {
        local arg = args.get(i)
        if arg == "--min-json" { min_mode = 1 }
        if arg == "--emit-mir" { emit_mir = 1 }
        i = i + 1
      }
    }
    local json = null
    local ast_json = null
    if min_mode == 1 {
      ast_json = "{\"version\":0,\"kind\":\"Program\",\"body\":[{\"type\":\"Return\",\"expr\":{\"type\":\"Int\",\"value\":0}}]}"
    } else {
      ast_json = me.parse_program(src, stage3_mode)
    }

    if emit_mir == 1 {
      // Lower minimal AST to MIR JSON (Return(Int) only for MVP)
      local mir = new MirEmitterBox()
      json = mir.emit_mir_min(ast_json)
    } else {
      // Emit Stage‑1 JSON with metadata
      local emitter = new EmitterBox()
      json = emitter.emit_program(ast_json, me._usings)
    }

    // Output JSON
    local console = new ConsoleBox()
    console.println(json)
    return 0
  }
}