import re
import pandas as pd
import gradio as gr

# ====================== CONFIG ======================
CSV_FILE = "game_data.csv"

df = pd.read_csv(CSV_FILE)
TOTAL_STAGES = len(df)

# ====================== HELPER ======================
def extract_start_seconds(url_str: str, default_seconds: int = 78) -> int:
    """
    Try to extract start time from:
      - t=78
      - start=78
    If not found, fall back to default_seconds (78).
    Supports URLs like: ...&t=78 or ...?t=78
    """
    if not url_str:
        return default_seconds

    s = str(url_str)

    # Common patterns: t=78 or start=78 (allow ?t=78 or &t=78)
    m = re.search(r"(?:[?&](?:t|start))=(\d+)", s)
    if m:
        return int(m.group(1))

    return default_seconds


def get_embed_url(youtube_url: str, start_seconds: int) -> str:
    """
    Converts a standard YouTube watch/share link into an embed link.
    Adds start time using ?start=...
    """
    url_str = str(youtube_url).strip()
    if not url_str:
        return ""

    video_id = ""

    if "youtu.be/" in url_str:
        video_id = url_str.split("youtu.be/")[1].split("?")[0].split("&")[0]
    elif "v=" in url_str:
        video_id = url_str.split("v=")[1].split("&")[0].split("?")[0]
    elif "embed/" in url_str:
        # If it's already an embed link, keep it but normalize start
        # (best effort: do not try to re-parse ID)
        base = url_str.split("?")[0]
        return f"{base}?start={start_seconds}"

    else:
        return ""

    return f"https://www.youtube.com/embed/{video_id}?start={start_seconds}"


def generate_iframe_html(embed_url: str) -> str:
    """Wraps an embed link inside a responsive HTML iframe."""
    if not embed_url:
        return "<p style='color:red;'>⚠️ Invalid YouTube link found in CSV!</p>"

    return f"""
    <div style="display: flex; justify-content: center; margin-bottom: 15px;">
        <iframe
            width="100%"
            height="315"
            src="{embed_url}"
            title="YouTube video player"
            frameborder="0"
            allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share"
            allowfullscreen>
        </iframe>
    </div>
    """


def get_stage_data(stage_index: int):
    if stage_index < 0 or stage_index >= TOTAL_STAGES:
        return None

    row = df.iloc[stage_index]

    raw_url = row.get("youtube_link", "")
    start_seconds = extract_start_seconds(raw_url, default_seconds=78)
    embed_url = get_embed_url(raw_url, start_seconds=start_seconds)
    iframe_code = generate_iframe_html(embed_url)

    title = row.get("title", f"Stage {stage_index + 1}")

    return {
        "stage_no": row.get("stage_no", stage_index + 1),
        "title": title,
        "song_name": str(row["song_name"]).strip(),
        "iframe_html": iframe_code,
        "lyrics": row.get("lyrics", "No lyrics available."),
    }


# ====================== GAME LOGIC ======================
def start_game():
    """
    Initializes stage but hides the YouTube iframe until user clicks Play Clip.
    """
    stage = get_stage_data(0)
    if stage is None:
        return (
            0,  # current_stage_idx
            0,  # current_score
            "",  # video_html_ui (empty -> hidden)
            f"",  # stage_title_ui
            "",  # lyrics_ui (content)
            "",  # guess_input value
            "",  # feedback_ui
            gr.update(visible=False),  # video_box visible
            gr.update(visible=True),   # game_box visible
            gr.update(visible=False),  # game_over_box visible
            gr.update(visible=True),   # play_btn visible
            gr.update(visible=False),  # next_btn visible
        )

    return (
        0,
        0,
        "",  # hide video until play
        f"## 🎵 {stage['title']}",
        stage["lyrics"],
        "",
        "",
        gr.update(visible=False),  # video_box hidden
        gr.update(visible=True),   # game_box visible
        gr.update(visible=False),  # game_over_box hidden
        gr.update(visible=True),   # show Play button
        gr.update(visible=False),  # next hidden
    )


def play_clip(current_idx: int):
    """
    Generates and shows the iframe for the current stage.
    """
    stage = get_stage_data(current_idx)
    if not stage:
        return (
            "",  # video_html_ui
            gr.update(visible=False),  # video_box
        )

    return (
        stage["iframe_html"],
        gr.update(visible=True),   # show video
    )


def show_lyrics():
    return gr.update(visible=True)


def check_guess(guess, current_idx, score):
    stage = get_stage_data(current_idx)
    if not stage:
        return (
            score,
            "Error: invalid stage.",
            gr.update(visible=False),  # next_btn
            gr.update(visible=False),  # game_over_box
        )

    is_correct = guess.strip().lower() == stage["song_name"].lower()

    if is_correct:
        score += 1
        feedback = "🎉 **Correct!**"
    else:
        feedback = f"❌ **Incorrect.** Correct answer: **{stage['song_name']}**"

    next_idx = current_idx + 1
    is_last = next_idx >= TOTAL_STAGES

    return (
        score,
        feedback,
        gr.update(visible=not is_last),  # show next if not last
        gr.update(visible=is_last),      # show game over if last
    )


def next_stage(current_idx):
    """
    Advances to next stage, hides iframe again, and shows Play button.
    """
    next_idx = current_idx + 1
    stage = get_stage_data(next_idx)

    if not stage:
        # End: keep iframe hidden, hide next
        return (
            current_idx,
            "",  # video_html_ui cleared
            f"",
            "",  # lyrics_ui content
            "",
            "",
            gr.update(visible=False),  # video_box hidden
            gr.update(visible=False),  # next_btn hidden
        )

    return (
        next_idx,
        "",  # clear video_html_ui
        f"## 🎵 {stage['title']}",
        stage["lyrics"],
        "",
        "",
        gr.update(visible=False),  # hide video again
        gr.update(visible=False),  # next_btn hidden until correct
    )


def end_game_summary(score):
    return f"## 🏆 Game Over!\n\nYou scored **{score}/{TOTAL_STAGES}**!"


# ====================== UI ======================
with gr.Blocks() as demo:
    gr.Markdown("# 🎧 Ultimate YouTube Music Guessing Game")
    gr.Markdown("Click ▶️ Play Clip to start. Then guess the song name!")

    current_stage_idx = gr.State(0)
    current_score = gr.State(0)

    with gr.Column(visible=True) as game_box:
        stage_title_ui = gr.Markdown()

        with gr.Row():
            with gr.Column():
                # Video area (we toggle visibility)
                with gr.Column(visible=False) as video_box:
                    video_html_ui = gr.HTML()

                play_btn = gr.Button("▶️ Play Clip", variant="secondary")

                lyrics_btn = gr.Button("💡 Show Lyrics")
                lyrics_ui = gr.Markdown(visible=False)

            with gr.Column():
                score_display = gr.Markdown("### Score: 0")
                guess_input = gr.Textbox(label="Your Guess", placeholder="Enter song name...")
                submit_btn = gr.Button("Submit", variant="primary")
                feedback_ui = gr.Markdown()
                next_btn = gr.Button("Next Stage ➡️", visible=False)

    with gr.Column(visible=False) as game_over_box:
        summary_ui = gr.Markdown()
        restart_btn = gr.Button("Play Again 🔄")

    # Start/load
    demo.load(
        fn=start_game,
        outputs=[
            current_stage_idx,
            current_score,
            video_html_ui,     # hidden (empty)
            stage_title_ui,
            lyrics_ui,         # lyrics content
            guess_input,
            feedback_ui,
            video_box,         # hide video
            game_box,          # show/hide game panel
            game_over_box,    # show/hide over panel
            play_btn,          # show play button
            next_btn,          # next hidden
        ],
    )

    # Play button (show iframe)
    play_btn.click(
        fn=play_clip,
        inputs=[current_stage_idx],
        outputs=[video_html_ui, video_box],
    )

    # Lyrics visibility
    lyrics_btn.click(
        fn=show_lyrics,
        outputs=lyrics_ui
    )

    # Submit guess
    submit_btn.click(
        fn=check_guess,
        inputs=[guess_input, current_stage_idx, current_score],
        outputs=[current_score, feedback_ui, next_btn, game_over_box],
    ).then(
        fn=lambda s: f"### Score: {s}",
        inputs=current_score,
        outputs=score_display
    ).then(
        fn=end_game_summary,
        inputs=current_score,
        outputs=summary_ui
    )

    # Next stage
    next_btn.click(
        fn=next_stage,
        inputs=[current_stage_idx],
        outputs=[
            current_stage_idx,  # stage idx
            video_html_ui,      # clear video html
            stage_title_ui,     # update title
            lyrics_ui,          # update lyrics content (still hidden unless user clicks)
            guess_input,        # clear guess
            feedback_ui,        # clear feedback
            video_box,          # hide video again
            next_btn,           # keep next hidden until correct guess
        ],
    ).then(
        fn=lambda: gr.update(visible=True),  # show play btn again
        inputs=[],
        outputs=[play_btn]
    )

    # Restart
    restart_btn.click(
        fn=start_game,
        outputs=[
            current_stage_idx,
            current_score,
            video_html_ui,
            stage_title_ui,
            lyrics_ui,
            guess_input,
            feedback_ui,
            video_box,
            game_box,
            game_over_box,
            play_btn,
            next_btn,
        ],
    ).then(
        fn=lambda s: f"### Score: {s}",
        inputs=current_score,
        outputs=score_display
    )

demo.launch()