// We use a progress file to keep track of where the user is
let progress_file = "tutorial/.sesi_tutorial_progress.json"

fn load_progress() {
  try {
    let content = read_file(progress_file)
    return from_json(content)
  } catch (err) {
    // Default progress state
    return {"step": 0, "name": "Developer"}
  }
}

fn save_progress(state) {
  try {
    write_file(progress_file, to_json(state))
  } catch (err) {
    print "Error saving progress:" err
  }
}

let state = load_progress()
let cmd = ""

// Sesi accepts args natively through the global `args` array!
if len(args) > 0 {
  cmd = args[0]
}

if cmd == "reset" {
  state["step"] = 0
  save_progress(state)
  print "Tutorial reset! Run 'npm run tutorial:cli' to start over."
  // Stop early
  let early_exit = true
} else if cmd == "next" {
  state["step"] = state["step"] + 1
  save_progress(state)
  print "Moving to step" str(state["step"]) "...\n"
} else if cmd == "name" {
  if len(args) > 1 {
    state["name"] = args[1]
    save_progress(state)
    print "Nice to meet you," state["name"] "!\n"
  } else {
    print "Please provide a name: npm run tutorial:cli name <your_name>"
    let early_exit = true
  }
}

let step = state["step"]

if cmd != "reset" && len(args) == 0 || cmd == "next" || cmd == "name" {
  if step == 0 {
    print "======================================"
    print "   Welcome to the Sesi CLI Tutorial!  "
    print "======================================"
    print "Hello," state["name"] "!"
    print "Sesi scripts accept arguments natively via the global 'args' array."
    print "To move forward, pass the 'next' argument:"
    print ""
    print "  👉 npm run tutorial:cli next"
    print ""
    print "Want to change your name? Run:"
    print "  👉 npm run tutorial:cli name Alice"
  } else if step == 1 {
    print "--- Step 1: Variables & Printing ---"
    print "In Sesi, you declare variables using 'let'."
    print "  let x = 10"
    print "  let msg = \"Hello\""
    print "  print msg x"
    print ""
    print "Notice how 'print' automatically spaces out arguments!"
    print ""
    print "  👉 npm run tutorial:cli next"
  } else if step == 2 {
    print "--- Step 2: Arrays and Loops ---"
    print "Sesi has modern collections and loops."
    print "  let items = [1, 2, 3]"
    print "  for item in items {"
    print "    print item"
    print "  }"
    print ""
    print "You can also use 'while' and numeric 'for' loops."
    print "  for i = 0 to 5 { ... }"
    print ""
    print "  👉 npm run tutorial:cli next"
  } else if step == 3 {
    print "--- Step 3: Optional Reasoning ---"
    print "Sesi has built-in Reasoning blocks. You don't need to set up anything."
    print "  prompt request {"
    print "    \"Summarize this text:\" text"
    print "  }"
    print "  let answer = model(\"gemini-3.1-flash-lite\") {request}"
    print ""
    print "It feels just like writing native code."
    print ""
    print "  👉 npm run tutorial:cli next"
  } else if step >= 4 {
    print "======================================"
    print "          Tutorial Complete!          "
    print "======================================"
    print "Great job," state["name"] "! You learned how to:"
    print "1. Pass native CLI args (using the args array)"
    print "2. Manage variables and loops"
    print "3. Read/write files (this script saved your progress!)"
    print "4. Use native AI blocks"
    print ""
    print "Check docs/WRITING_SCRIPTS.md to build your own tools."
    print ""
    print "To restart:"
    print "  👉 npm run tutorial:cli reset"
  }
}
