"""
AI Subtitle & SRT Generator -- Studio Web Application
======================================================

A production-grade, cloud-deployable AI Subtitle and SRT Generator web app
powered by **Faster-Whisper** (`large-v3` model) and **FFmpeg**.

Designed with a high-end Olive & Crisp White studio aesthetic inspired by
modern SaaS creator platforms (VEED, Descript, Happy Scribe, Riverside, Rev).

Usage
-----
    python app.py          # starts at http://localhost:7860
"""

from __future__ import annotations

import logging
import sys
from pathlib import Path

import gradio as gr

# ---------------------------------------------------------------------------
# Logging Configuration
# ---------------------------------------------------------------------------

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s | %(levelname)-8s | %(name)s | %(message)s",
    datefmt="%Y-%m-%d %H:%M:%S",
    handlers=[logging.StreamHandler(sys.stdout)],
)
logger = logging.getLogger("app")

# ---------------------------------------------------------------------------
# Local Imports
# ---------------------------------------------------------------------------

from utils.helpers import (  # noqa: E402
    validate_uploaded_file,
    ensure_directories,
    cleanup_temp_file,
    format_duration,
)
from services.media_processor import extract_audio_to_wav, get_audio_duration  # noqa: E402
from services.transcription import transcribe_audio, LANGUAGE_MAP  # noqa: E402
from services.subtitle_generator import generate_srt_file, generate_preview_text  # noqa: E402

# ---------------------------------------------------------------------------
# Bootstrap Runtime Directories
# ---------------------------------------------------------------------------

ensure_directories()

LANGUAGE_CHOICES: list[str] = [
    "🌐 Auto-detect (Recommended)",
    "🇬🇧 English",
    "🇧🇩 Bangla (বাংলা)",
    "🔀 Mixed / Banglish",
]

_ACCEPTED_FILE_TYPES: list[str] = [
    ".mp4", ".mkv", ".avi", ".mov", ".webm", ".flv", ".wmv", ".m4v",
    ".mp3", ".wav", ".flac", ".aac", ".ogg", ".m4a", ".wma", ".opus",
]


# ═══════════════════════════════════════════════════════════════════════════
# Processing Pipeline
# ═══════════════════════════════════════════════════════════════════════════


def process_media(
    file_path: str | None,
    language: str,
    progress: gr.Progress = gr.Progress(),
) -> tuple[str, str | None]:
    """
    End-to-end subtitle generation pipeline.

    Steps: Validate -> FFmpeg 16kHz WAV -> Whisper large-v3 -> SRT Generation.

    Returns
    -------
    tuple[str, str | None]
        ``(preview_text, srt_file_path_or_none)``
    """
    wav_path: str | None = None

    try:
        # -- Step 1: Validate upload ------------------------------------
        progress(0.05, desc="📁 Validating media file ...")
        is_valid, message = validate_uploaded_file(file_path)
        if not is_valid:
            return f"❌ Validation Error:\n{message}", None

        logger.info("Processing media: %s | language=%s", file_path, language)
        original_name = Path(file_path).name

        # -- Step 2: Extract audio with FFmpeg --------------------------
        progress(0.15, desc="🎵 Extracting 16 kHz studio WAV via FFmpeg ...")
        wav_path = extract_audio_to_wav(file_path)

        duration = get_audio_duration(wav_path)
        if duration:
            logger.info("Audio duration: %s", format_duration(duration))

        # -- Step 3: Transcribe with Faster-Whisper large-v3 ------------
        progress(0.35, desc="⚡ Transcribing with Whisper large-v3 engine ...")
        result = transcribe_audio(wav_path, language=language)

        if not result.segments:
            return (
                "⚠️ No audible speech detected.\n\n"
                "💡 Helpful Tips:\n"
                "  • Ensure the file contains clear, audible spoken dialogue.\n"
                "  • For mixed speech, leave Language set to Auto-detect.\n"
                "  • Verify that the audio stream is not muted or heavily degraded.",
                None,
            )

        # -- Step 4: Generate SRT Subtitle file -------------------------
        progress(0.85, desc="📝 Formatting SRT timestamps & building file ...")
        srt_path, _ = generate_srt_file(result, original_name)

        # -- Step 5: Build preview text ---------------------------------
        progress(0.95, desc="✨ Subtitle generation complete!")
        preview = generate_preview_text(result)

        return preview, srt_path

    except EnvironmentError as exc:
        logger.error("Environment error: %s", exc)
        return f"❌ Environment Error:\n{exc}", None
    except FileNotFoundError as exc:
        logger.error("File not found: %s", exc)
        return f"❌ File Error:\n{exc}", None
    except RuntimeError as exc:
        logger.error("Runtime error: %s", exc)
        return f"❌ Processing Error:\n{exc}", None
    except Exception as exc:
        logger.exception("Unexpected error during subtitle processing")
        return (
            f"❌ Unexpected Error ({type(exc).__name__}):\n{exc}\n\n"
            "Please check the file format or try another media file.",
            None,
        )
    finally:
        if wav_path:
            cleanup_temp_file(wav_path)


# ═══════════════════════════════════════════════════════════════════════════
# Professional Custom CSS (Olive & Crisp White Creator Palette)
# ═══════════════════════════════════════════════════════════════════════════

CUSTOM_CSS = """
/* ========== Global Page Canvas & Olive/White Palette ========== */
:root {
    --olive-dark: #2B382A;
    --olive-primary: #3E4F3C;
    --olive-medium: #52674F;
    --olive-light: #6E846A;
    --olive-soft: #DDE8DA;
    --olive-tint: #EEF4EB;
    --olive-bg: #F3F7F1;
    --white-card: #FFFFFF;
    --text-charcoal: #1E281D;
    --text-muted: #576854;
    --border-subtle: rgba(62, 79, 60, 0.16);
    --border-strong: rgba(62, 79, 60, 0.28);
}

body, gradio-app {
    background: linear-gradient(180deg, #F3F7F1 0%, #E7EFE4 45%, #DCE7D9 100%) !important;
    color: var(--text-charcoal) !important;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif !important;
    min-height: 100vh;
}

.gradio-container {
    max-width: 1060px !important;
    margin: 0 auto !important;
    background: transparent !important;
    padding: 1rem !important;
}

/* ========== Hero Section (Deep Olive Banner with Crisp White Elements) ========== */
.studio-hero-card {
    background: linear-gradient(135deg, #243023 0%, #354433 50%, #465744 100%);
    border-radius: 20px;
    padding: 2.4rem 1.8rem;
    text-align: center;
    box-shadow: 0 12px 36px rgba(36, 48, 35, 0.18);
    border: 1px solid rgba(255, 255, 255, 0.12);
    margin-bottom: 1.4rem;
    position: relative;
    overflow: hidden;
}

.studio-pill-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    background: rgba(238, 244, 235, 0.16);
    border: 1px solid rgba(238, 244, 235, 0.35);
    color: #E2ECDSubtle;
    color: #EEF4EB;
    font-size: 0.84rem;
    font-weight: 700;
    padding: 0.38rem 1.1rem;
    border-radius: 9999px;
    margin-bottom: 1rem;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.studio-title {
    font-size: 2.5rem !important;
    font-weight: 800 !important;
    letter-spacing: -0.025em !important;
    color: #FFFFFF !important;
    margin: 0.2rem 0 0.7rem 0 !important;
    line-height: 1.2 !important;
}

.studio-subtitle {
    color: #DDE8DA !important;
    font-size: 1.05rem;
    max-width: 680px;
    margin: 0 auto 0.5rem auto;
    line-height: 1.6;
}

/* ========== 4-Step Workflow Cards (Crisp White + Olive Trim) ========== */
.workflow-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 0.85rem;
    margin: 0.5rem 0 1.5rem 0;
}

.step-card {
    background: var(--white-card);
    border: 1px solid var(--border-subtle);
    border-radius: 14px;
    padding: 1rem 1.1rem;
    display: flex;
    align-items: center;
    gap: 0.85rem;
    box-shadow: 0 4px 16px rgba(43, 56, 42, 0.05);
    transition: all 0.22s ease;
}

.step-card:hover {
    border-color: var(--olive-primary);
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(43, 56, 42, 0.1);
}

.step-icon-box {
    width: 44px;
    height: 44px;
    border-radius: 10px;
    background: var(--olive-tint);
    border: 1px solid var(--olive-soft);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.35rem;
    flex-shrink: 0;
}

.step-info {
    text-align: left;
}

.step-number {
    font-size: 0.72rem;
    font-weight: 800;
    text-transform: uppercase;
    color: var(--olive-medium);
    letter-spacing: 0.06em;
}

.step-label {
    font-size: 0.92rem;
    font-weight: 700;
    color: var(--text-charcoal);
}

/* ========== Content Cards (Crisp White Panels) ========== */
.card, .gr-box, .gr-panel, .gr-form {
    background: var(--white-card) !important;
    border: 1px solid var(--border-subtle) !important;
    border-radius: 16px !important;
    box-shadow: 0 4px 20px rgba(43, 56, 42, 0.05) !important;
}

.panel-title {
    font-size: 0.95rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--olive-dark);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin: 0.4rem 0 0.6rem 0;
}

/* ========== Format Chips (Olive Pastel Tags) ========== */
.chips-container {
    display: flex;
    flex-wrap: wrap;
    gap: 0.45rem;
    margin: 0.6rem 0 0.9rem 0;
}

.format-chip {
    background: var(--olive-tint);
    border: 1px solid rgba(62, 79, 60, 0.2);
    color: var(--olive-dark);
    font-size: 0.78rem;
    font-weight: 700;
    padding: 0.28rem 0.65rem;
    border-radius: 8px;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
}

/* ========== Action Button (Rich Deep Olive Gradient) ========== */
.generate-btn {
    background: linear-gradient(135deg, #2E3B2C 0%, #465843 50%, #2E3B2C 100%) !important;
    border: none !important;
    color: #FFFFFF !important;
    font-weight: 800 !important;
    font-size: 1.08rem !important;
    padding: 0.9rem 1.8rem !important;
    border-radius: 12px !important;
    box-shadow: 0 6px 24px rgba(46, 59, 44, 0.3) !important;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1) !important;
    width: 100% !important;
    cursor: pointer !important;
    margin-top: 0.6rem !important;
}

.generate-btn:hover {
    background: linear-gradient(135deg, #243023 0%, #3B4B38 50%, #243023 100%) !important;
    transform: translateY(-2px) !important;
    box-shadow: 0 10px 30px rgba(46, 59, 44, 0.45) !important;
}

.generate-btn:active {
    transform: translateY(0) !important;
}

/* ========== Input & Textarea Refinement ========== */
input, textarea, select, .gr-input, .gr-textarea {
    background: #FAFCF9 !important;
    border: 1px solid var(--border-strong) !important;
    color: var(--text-charcoal) !important;
    border-radius: 10px !important;
}

input:focus, textarea:focus, select:focus {
    border-color: var(--olive-primary) !important;
    box-shadow: 0 0 0 3px rgba(62, 79, 60, 0.15) !important;
}



/* ========== Studio Footer ========== */
.studio-footer {
    text-align: center;
    padding: 2rem 1rem 1rem;
    color: var(--text-muted);
    font-size: 0.85rem;
    border-top: 1px solid var(--border-subtle);
    margin-top: 2.2rem;
}

/* Hide default Gradio footer */
footer { display: none !important; }
"""


# ═══════════════════════════════════════════════════════════════════════════
# Gradio UI Construction
# ═══════════════════════════════════════════════════════════════════════════


def build_ui() -> gr.Blocks:
    """Construct and return the redesigned Olive & White Gradio Studio UI."""

    with gr.Blocks(title="AI Subtitle & SRT Generator | Studio") as app:

        # -- Hero Banner (Deep Olive + Crisp White) -----------------
        gr.HTML(
            '<div class="studio-hero-card">'
            '  <div class="studio-pill-badge">'
            "    🎬 AI Video &amp; Audio Subtitle Studio &middot; 2-Line Subtitle Standard 🎙️"
            "  </div>"
            '  <h1 class="studio-title">AI Subtitle &amp; SRT Generator</h1>'
            '  <p class="studio-subtitle">'
            "    Convert video and audio recordings into professional, broadcast-compliant "
            "<strong>.srt</strong> subtitles (strictly <strong>max 2 lines per timestamp</strong>) powered by "
            "<strong>Faster-Whisper large-v3</strong>. Engineered for creators, editors, and podcasters."
            "  </p>"
            "</div>"
        )

        # -- 4-Step Workflow Grid (Crisp White + Olive Trim) --------
        gr.HTML(
            '<div class="workflow-grid">'
            '  <div class="step-card">'
            '    <div class="step-icon-box">📁</div>'
            '    <div class="step-info">'
            '      <div class="step-number">Step 01</div>'
            '      <div class="step-label">Upload Media</div>'
            "    </div>"
            "  </div>"
            '  <div class="step-card">'
            '    <div class="step-icon-box">🌐</div>'
            '    <div class="step-info">'
            '      <div class="step-number">Step 02</div>'
            '      <div class="step-label">Select Language</div>'
            "    </div>"
            "  </div>"
            '  <div class="step-card">'
            '    <div class="step-icon-box">⚡</div>'
            '    <div class="step-info">'
            '      <div class="step-number">Step 03</div>'
            '      <div class="step-label">Whisper large-v3</div>'
            "    </div>"
            "  </div>"
            '  <div class="step-card">'
            '    <div class="step-icon-box">📥</div>'
            '    <div class="step-info">'
            '      <div class="step-number">Step 04</div>'
            '      <div class="step-label">Download .SRT</div>'
            "    </div>"
            "  </div>"
            "</div>"
        )

        # -- Main Dual-Pane Studio Layout ---------------------------
        with gr.Row(equal_height=False):

            # == Left Column: Media Inputs & Settings ===============
            with gr.Column(scale=1):

                gr.HTML(
                    '<div class="panel-title">'
                    "  <span>🎬 Media File Upload</span>"
                    "</div>"
                )

                file_input = gr.File(
                    label="Select Video or Audio File",
                    file_types=_ACCEPTED_FILE_TYPES,
                    type="filepath",
                )

                # Format chips in pastel olive tags
                gr.HTML(
                    '<div class="chips-container">'
                    '  <span class="format-chip">🎬 MP4</span>'
                    '  <span class="format-chip">🎞️ MKV</span>'
                    '  <span class="format-chip">📽️ MOV</span>'
                    '  <span class="format-chip">🎥 WebM</span>'
                    '  <span class="format-chip">🎵 MP3</span>'
                    '  <span class="format-chip">🎧 WAV</span>'
                    '  <span class="format-chip">🎼 FLAC</span>'
                    '  <span class="format-chip">🎙️ M4A</span>'
                    '  <span class="format-chip">🔊 AAC</span>'
                    '  <span class="format-chip">📦 Max 500 MB</span>'
                    "</div>"
                )

                gr.HTML(
                    '<div class="panel-title" style="margin-top: 1.1rem;">'
                    "  <span>🌐 Speech &amp; Language Configuration</span>"
                    "</div>"
                )

                language_dropdown = gr.Dropdown(
                    choices=LANGUAGE_CHOICES,
                    value="🌐 Auto-detect (Recommended)",
                    label="Spoken Language",
                    info="Supports English, Bangla, and Mixed Bangla-English (Banglish).",
                )

                generate_btn = gr.Button(
                    "✨ Generate Studio Subtitles 🎬",
                    variant="primary",
                    size="lg",
                    elem_classes=["generate-btn"],
                )

                # Engine badge
                gr.HTML(
                    '<div style="text-align: center; margin-top: 0.85rem; font-size: 0.8rem; color: #576854; font-weight: 600;">'
                    "  🎙️ Engine: <strong>Faster-Whisper large-v3</strong> (1.55B Parameters &middot; int8 Quantized)"
                    "</div>"
                )

            # == Right Column: Preview & Subtitle Download ==========
            with gr.Column(scale=1):

                gr.HTML(
                    '<div class="panel-title">'
                    "  <span>📝 Live Transcript &amp; Timestamps Preview</span>"
                    "</div>"
                )

                preview_box = gr.Textbox(
                    label="Studio Transcript",
                    placeholder="Transcription summary and timestamped subtitle blocks will appear here...",
                    lines=18,
                    max_lines=32,
                    interactive=False,
                )

                gr.HTML(
                    '<div class="panel-title" style="margin-top: 1rem;">'
                    "  <span>⬇️ Export &amp; Download</span>"
                    "</div>"
                )

                download_file = gr.File(
                    label="Download .SRT Subtitle File",
                    interactive=False,
                )

        # -- Interactive Workflow Wiring ----------------------------
        generate_btn.click(
            fn=process_media,
            inputs=[file_input, language_dropdown],
            outputs=[preview_box, download_file],
        )



        # -- Studio Footer ------------------------------------------
        gr.HTML(
            '<div class="studio-footer">'
            "  🎬 <strong>AI Subtitle &amp; SRT Generator Studio</strong> &middot; "
            "  🎵 Built for Creators, Podcasters &amp; Editors &middot; "
            "  ⚡ Powered by <strong>Faster-Whisper large-v3</strong> &amp; <strong>FFmpeg</strong>"
            "</div>"
        )

    return app


# ═══════════════════════════════════════════════════════════════════════════
# Application Entrypoint
# ═══════════════════════════════════════════════════════════════════════════

if __name__ == "__main__":
    application = build_ui()
    application.launch(
        server_name="0.0.0.0",
        server_port=7860,
        share=True,
        show_error=True,
        css=CUSTOM_CSS,
        theme=gr.themes.Soft(
            primary_hue="emerald",
            secondary_hue="stone",
            neutral_hue="stone",
        ),
    )