import streamlit as st
import streamlit_ace as st_ace
from utils import execute_code
from chatbot import render_chatbot
from layout import init_session_state, apply_theme

# Page Setup
st.set_page_config(page_title="Pro Code Playground", page_icon="💻", layout="wide")
init_session_state()

# Header
st.title("Pro Code Playground")
st.markdown("Write, execute & export multi-language snippets, with built‑in AI assistance.")

# Define default code snippets
DEFAULT_SNIPPETS = {
    "Python": '''# default code\na = int(input())\nb = int(input())\nprint("Sum:", a + b)''',
    "C": '''// default code\n#include <stdio.h>\nint main() {\n    int a, b;\n    scanf("%d %d", &a, &b);\n    printf("Sum: %d\\n", a + b);\n    return 0;\n}''',
    "C++": '''// default code\n#include <iostream>\nusing namespace std;\nint main() {\n    int a, b;\n    cin >> a >> b;\n    cout << "Sum: " << a + b << endl;\n    return 0;\n}''',
    "Java": '''// default code\nimport java.util.Scanner;\npublic class Program {\n    public static void main(String[] args) {\n        Scanner sc = new Scanner(System.in);\n        int a = sc.nextInt();\n        int b = sc.nextInt();\n        System.out.println("Sum: " + (a + b));\n    }\n}''',
    "JavaScript": '''// default code\nconst readline = require('readline');\nconst rl = readline.createInterface({ input: process.stdin, output: process.stdout });\nlet inputs = [];\nrl.on('line', (line) => {\n  inputs.push(parseInt(line));\n  if (inputs.length === 2) {\n    console.log("Sum:", inputs[0] + inputs[1]);\n    rl.close();\n  }\n});''',
    "C#": '''// default code\nusing System;\npublic class Program {\n    public static void Main(string[] args) {\n        int a = Convert.ToInt32(Console.ReadLine());\n        int b = Convert.ToInt32(Console.ReadLine());\n        Console.WriteLine("Sum: " + (a + b));\n    }\n}'''
}

# Language + Theme selection
lang_col, spacer, theme_col = st.columns([3, 6, 1])
with lang_col:
    selected_lang = st.selectbox("Language", list(DEFAULT_SNIPPETS.keys()), index=0)

with theme_col:
    theme_choice = st.radio("Theme", options=["☀️", "🌙"], horizontal=True, label_visibility="collapsed")
    st.session_state.dark_mode = (theme_choice == "🌙")

# Apply theme
colors, ace_theme = apply_theme()

# Initialize code for language
prev_lang = st.session_state.get("prev_language", None)
if (
    selected_lang != prev_lang
    or st.session_state.get("code") is None
    or st.session_state.code.strip() == ""
    or st.session_state.code.strip() == DEFAULT_SNIPPETS.get(prev_lang, "")
):
    st.session_state.code = DEFAULT_SNIPPETS[selected_lang]
st.session_state.prev_language = selected_lang

# Generate dynamic editor key so it refreshes
editor_key = f"editor_{selected_lang}"

# Layout: Editor + Chatbot
gen, bot = st.columns((2, 1), gap="large")
with gen:
    st.subheader("Editor")

    code = st_ace.st_ace(
        value=st.session_state.code,
        placeholder=f"Start typing your {selected_lang} code…",
        language=selected_lang.lower() if selected_lang != "C++" else "c_cpp",
        theme=ace_theme,
        keybinding="vscode",
        font_size=14,
        min_lines=20,
        show_gutter=True,
        wrap=True,
        auto_update=True,
        key=editor_key  # key now varies with language
    )

    if code != st.session_state.code:
        st.session_state.code = code

    user_input = st.text_area(
        label="📥 Input (stdin)",
        value=st.session_state.stdin,
        placeholder="Enter input() values here, one per line",
        height=100,
        key="stdin_input"
    )
    if user_input != st.session_state.stdin:
        st.session_state.stdin = user_input

    if st.button("▶️ Run"):
        out, err, exc = execute_code(
            code=st.session_state.code,
            stdin=st.session_state.stdin,
            language=selected_lang
        )
        st.session_state.code_output = out
        st.session_state.error_output = err or exc

    if st.session_state.get("code_output"):
        st.text_area("Output", st.session_state.code_output, height=120)

    if st.session_state.get("error_output"):
        st.error(st.session_state.error_output)

with bot:
    st.subheader("Code Assistant")
    render_chatbot(
        st.session_state.code,
        st.session_state.get("code_output", ""),
        st.session_state.get("error_output", "")
    )

# Footer
st.markdown("""
<div style='text-align:center; margin-top:1rem; opacity:0.6;'>
  Built with ❤️ & Streamlit by Vaibhav
</div>
""", unsafe_allow_html=True)