"""
app.py
──────────────────────────────────────────────────────────────────────────────
VoiceVerse Pro — Streamlit Orchestrator  (2026 Stable Build)

This file is intentionally thin. Its only jobs are:
  1. Configure the Streamlit page
  2. Inject global CSS
  3. Render the header and stage tracker
  4. Delegate every pipeline stage to its own UI module
  5. Provide a debug panel for development

All business logic lives in  modules/
All UI rendering logic lives in  ui/

Pipeline flow:
  ui.sidebar         → SidebarConfig
  ui.stage_upload    → PipelineState.stage 0 → 1
  ui.stage_retrieve  → PipelineState.stage 1 → 2
  ui.stage_generate  → PipelineState.stage 2 → 3
  ui.stage_audio     → PipelineState.stage 3 → 4
"""

import logging
import os
import sys

# ── Path fix: ensure the project root is on sys.path regardless of where
#    `streamlit run` is invoked from. Without this, `import ui` and
#    `import modules` fail when the CWD is not the project root.
sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))

import streamlit as st
from dotenv import load_dotenv

load_dotenv()   # loads .env → os.environ before any module reads env vars

from ui import (
    get_pipeline_state,
    inject_css,
    render_header,
    render_stage_tracker,
    render_mode_selector,
    sidebar,
    stage_upload,
    stage_retrieve,
    stage_generate,
    stage_audio,
)

# ── Logging ───────────────────────────────────────────────────────────────────
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s | %(levelname)s | %(name)s | %(message)s",
)

# ── Page config (must be first Streamlit call) ────────────────────────────────
st.set_page_config(
    page_title="VoiceVerse Pro",
    page_icon="🎙️",
    layout="wide",
    initial_sidebar_state="expanded",
)

# ── Global styles ─────────────────────────────────────────────────────────────
inject_css()

# ── Session state ─────────────────────────────────────────────────────────────
state = get_pipeline_state()

# ── Sidebar → typed SidebarConfig ────────────────────────────────────────────
config = sidebar.render(current_stage=state.stage)

# ── Header + stage tracker ────────────────────────────────────────────────────
render_header()
render_stage_tracker(state.stage)

# ── Mode selector (prominent main-area toggle) ────────────────────────────────
selected_mode = render_mode_selector()

# Sync the session-state selection back into config so all stages see it
from ui.state import OutputMode
config.output_mode = OutputMode(selected_mode)

# ── Two-column layout ─────────────────────────────────────────────────────────
col_left, col_right = st.columns([1, 1.3], gap="large")

with col_left:
    stage_upload.render(state, config)
    stage_retrieve.render(state, config)

with col_right:
    stage_generate.render(state, config)
    stage_audio.render(state, config)

# ── Debug panel ───────────────────────────────────────────────────────────────
st.divider()
with st.expander("🛠️ Debug & System Info", expanded=False):
    import sys, platform
    st.markdown(
        f"**Python:** `{sys.version}`  \n"
        f"**Platform:** `{platform.platform()}`  \n"
        f"**Pipeline Stage:** `{state.stage}`  \n"
        f"**Chunks Indexed:** `{state.total_chunks}`  \n"
        f"**Context Retrieved:** `{state.has_context}`  \n"
        f"**Script Generated:** `{state.has_script}`  \n"
        f"**Audio Ready:** `{state.has_audio}`"
    )
    if st.button("🔄 Reset All State"):
        for k in list(st.session_state.keys()):
            del st.session_state[k]
        st.rerun()