import pandas as pd
import streamlit as st
import matplotlib.pyplot as plt
import matplotlib.font_manager as font_manager
from matplotlib.lines import Line2D
import io
import base64
import os
from datetime import datetime, timedelta
from pypinyin import lazy_pinyin, Style
from matplotlib.backends.backend_pdf import PdfPages

def get_font(size=14):
    """Loads a specific TrueType font, defaulting to a common Chinese font."""
    font_path = "simHei.ttc"
    if not os.path.exists(font_path):
        font_path = "SimHei.ttf"
    if os.path.exists(font_path):
        return font_manager.FontProperties(fname=font_path, size=size)
    else:
        st.warning("SimHei font not found. Display may not be correct. Please add simHei.ttc or SimHei.ttf.")
        return font_manager.FontProperties(family='sans-serif', size=size)

def get_pinyin_abbr(text):
    """Gets the first letter of the Pinyin for the first two Chinese characters of a text."""
    if not text:
        return ""
    chars = [c for c in text if '\u4e00' <= c <= '\u9fff'][:2]
    if not chars:
        return ""
    pinyin_list = lazy_pinyin(chars, style=Style.FIRST_LETTER)
    return ''.join(pinyin_list).upper()

def format_seq(n):
    """Converts an integer to a circled number string (e.g., 1 -> ①)."""
    if not isinstance(n, int) or n <= 0:
        return str(n)
    # Unicode characters for circled numbers 1-50
    circled_chars = "①②③④⑤⑥⑦⑧⑨⑩⑪⑫⑬⑭⑮⑯⑰⑱⑲⑳" \
                    "㉑㉒㉓㉔㉕㉖㉗㉘㉙㉚㉛㉜㉝㉞㉟" \
                    "㊱㊲㊳㊴㊵㊶㊷㊸㊹㊺㊻㊼㊽㊾㊿"
    if 1 <= n <= 50:
        return circled_chars[n-1]
    return f'({n})'  # Fallback for numbers greater than 50

def process_schedule(file):
    """
    Processes the uploaded Excel file to extract and clean the movie schedule data.
    Adds a sequence number for movies within each hall.
    """
    try:
        date_df = pd.read_excel(file, header=None, skiprows=7, nrows=1, usecols=[3])
        date_str = pd.to_datetime(date_df.iloc[0, 0]).strftime('%Y-%m-%d')
        base_date = pd.to_datetime(date_str).date()
    except Exception:
        date_str = datetime.today().strftime('%Y-%m-%d')
        base_date = datetime.today().date()

    try:
        df = pd.read_excel(file, header=9, usecols=[1, 2, 4, 5])
        df.columns = ['Hall', 'StartTime', 'EndTime', 'Movie']
        
        df['Hall'] = df['Hall'].ffill()
        df.dropna(subset=['StartTime', 'EndTime', 'Movie'], inplace=True)
        df['Hall'] = df['Hall'].astype(str).str.extract(r'(\d+号)')
        
        df['StartTime_dt'] = pd.to_datetime(df['StartTime'], format='%H:%M', errors='coerce').apply(
            lambda t: t.replace(year=base_date.year, month=base_date.month, day=base_date.day) if pd.notnull(t) else t
        )
        df['EndTime_dt'] = pd.to_datetime(df['EndTime'], format='%H:%M', errors='coerce').apply(
            lambda t: t.replace(year=base_date.year, month=base_date.month, day=base_date.day) if pd.notnull(t) else t
        )
        df.loc[df['EndTime_dt'] < df['StartTime_dt'], 'EndTime_dt'] += timedelta(days=1)
        df = df.sort_values(['Hall', 'StartTime_dt'])

        merged_rows = []
        for _, group in df.groupby('Hall'):
            current = None
            for _, row in group.sort_values('StartTime_dt').iterrows():
                if current is None:
                    current = row.copy()
                elif row['Movie'] == current['Movie']:
                    current['EndTime_dt'] = row['EndTime_dt']
                else:
                    merged_rows.append(current)
                    current = row.copy()
            if current is not None:
                merged_rows.append(current)
        
        merged_df = pd.DataFrame(merged_rows)
        
        merged_df['StartTime_dt'] -= timedelta(minutes=10)
        merged_df['EndTime_dt'] -= timedelta(minutes=5)
        
        merged_df['Seq'] = merged_df.groupby('Hall').cumcount() + 1
        
        merged_df['StartTime_str'] = merged_df['StartTime_dt'].dt.strftime('%H:%M')
        merged_df['EndTime_str'] = merged_df['EndTime_dt'].dt.strftime('%H:%M')
        
        return merged_df[['Hall', 'Seq', 'Movie', 'StartTime_str', 'EndTime_str']], date_str
    except Exception as e:
        st.error(f"Error processing schedule data: {e}. Please check the file format.")
        return None, date_str


def create_print_layout(data, date_str):
    """
    Generates PNG and PDF print layouts for the movie schedule based on a dynamic grid.
    """
    if data is None or data.empty:
        return None

    # --- 1. Layout and Column Calculation ---
    A4_width_in, A4_height_in = 8.27, 11.69
    dpi = 300

    total_content_rows = len(data)
    totalA = total_content_rows + 2
    row_height = A4_height_in / totalA

    # Prepare data strings for width calculation
    data = data.reset_index(drop=True)
    # Format Hall number with LaTeX for superscript
    data['hall_str'] = '$' + data['Hall'].str.replace('号', '') + '^{\#}$'
    # Format sequence number as circled character
    data['seq_str'] = data['Seq'].apply(format_seq)
    data['pinyin_abbr'] = data['Movie'].apply(get_pinyin_abbr)
    data['time_str'] = data['StartTime_str'] + ' - ' + data['EndTime_str']

    temp_fig = plt.figure(figsize=(A4_width_in, A4_height_in), dpi=dpi)
    renderer = temp_fig.canvas.get_renderer()

    base_font_size_pt = (row_height * 0.9) * 72
    # Specific font size for circled numbers (50% of row height)
    seq_font_size_pt = (row_height * 0.5) * 72
    
    def get_col_width_in(series, font_size_pt, is_math=False):
        """Calculates the required width for a column in inches."""
        if series.empty:
            return 0
        font_prop = get_font(font_size_pt)
        longest_str_idx = series.astype(str).str.len().idxmax()
        max_content = str(series.loc[longest_str_idx])
        text_width_px, _, _ = renderer.get_text_width_height_descent(max_content, font_prop, ismath=is_math)
        return (text_width_px / dpi) * 1.1

    # Calculate widths for all columns
    margin_col_width = row_height
    # Pass is_math=True for hall number width calculation
    hall_col_width = get_col_width_in(data['hall_str'], base_font_size_pt, is_math=True)
    # Use the smaller font size for sequence number width calculation
    seq_col_width = get_col_width_in(data['seq_str'], seq_font_size_pt)
    pinyin_col_width = get_col_width_in(data['pinyin_abbr'], base_font_size_pt)
    time_col_width = get_col_width_in(data['time_str'], base_font_size_pt)

    movie_col_width = A4_width_in - (margin_col_width * 2 + hall_col_width + seq_col_width + pinyin_col_width + time_col_width)
    
    plt.close(temp_fig)

    col_widths = {'hall': hall_col_width, 'seq': seq_col_width, 'movie': movie_col_width, 'pinyin': pinyin_col_width, 'time': time_col_width}
    col_x_starts = {}
    current_x = margin_col_width
    for col_name in ['hall', 'seq', 'movie', 'pinyin', 'time']:
        col_x_starts[col_name] = current_x
        current_x += col_widths[col_name]

    # --- 2. Drawing ---
    def draw_figure(fig, ax):
        renderer = fig.canvas.get_renderer()
        
        for col_name in ['hall', 'seq', 'movie', 'pinyin']:
            x_line = col_x_starts[col_name] + col_widths[col_name]
            line_top_y, line_bottom_y = A4_height_in - row_height, row_height
            ax.add_line(Line2D([x_line, x_line], [line_bottom_y, line_top_y], color='gray', linestyle=':', linewidth=0.5))

        last_hall_drawn = None
        for i, row in data.iterrows():
            y_bottom = A4_height_in - (i + 2) * row_height
            y_center = y_bottom + row_height / 2

            # --- Draw Cell Content ---
            # Hall Number (renders superscript)
            if row['Hall'] != last_hall_drawn:
                ax.text(col_x_starts['hall'] + col_widths['hall'] / 2, y_center, row['hall_str'],
                        fontproperties=get_font(base_font_size_pt), ha='center', va='center')
                last_hall_drawn = row['Hall']

            # Sequence Number (with smaller, specific font size)
            ax.text(col_x_starts['seq'] + col_widths['seq'] / 2, y_center, row['seq_str'],
                    fontproperties=get_font(seq_font_size_pt), ha='center', va='center')

            # Pinyin Abbreviation
            ax.text(col_x_starts['pinyin'] + col_widths['pinyin'] / 2, y_center, row['pinyin_abbr'],
                    fontproperties=get_font(base_font_size_pt), ha='center', va='center')

            # Time String
            ax.text(col_x_starts['time'] + col_widths['time'] / 2, y_center, row['time_str'],
                    fontproperties=get_font(base_font_size_pt), ha='center', va='center')

            # Movie Title (with font scaling)
            movie_font_size = base_font_size_pt
            movie_font_prop = get_font(movie_font_size)
            text_w_px, _, _ = renderer.get_text_width_height_descent(row['Movie'], movie_font_prop, ismath=False)
            text_w_in = text_w_px / dpi
            
            max_width_in = col_widths['movie'] * 0.9
            if text_w_in > max_width_in:
                movie_font_size *= (max_width_in / text_w_in)
                movie_font_prop = get_font(movie_font_size)
            
            ax.text(col_x_starts['movie'] + 0.05, y_center, row['Movie'],
                    fontproperties=movie_font_prop, ha='left', va='center')

            # --- Draw Horizontal Lines ---
            is_last_in_hall = (i == len(data) - 1) or (row['Hall'] != data.loc[i + 1, 'Hall'])
            
            line_start_x = margin_col_width
            line_end_x = A4_width_in - margin_col_width
            if is_last_in_hall:
                ax.add_line(Line2D([line_start_x, line_end_x], [y_bottom, y_bottom], color='black', linestyle='-', linewidth=0.8))
            else:
                ax.add_line(Line2D([line_start_x, line_end_x], [y_bottom, y_bottom], color='gray', linestyle=':', linewidth=0.5))

    # --- 3. Setup Figures and Generate Output ---
    outputs = {}
    for format_type in ['png', 'pdf']:
        fig = plt.figure(figsize=(A4_width_in, A4_height_in), dpi=dpi)
        ax = fig.add_axes([0, 0, 1, 1])
        ax.set_axis_off()
        ax.set_xlim(0, A4_width_in)
        ax.set_ylim(0, A4_height_in)
        
        ax.text(margin_col_width, A4_height_in - (row_height/2), date_str, 
                fontproperties=get_font(10), color='#A9A9A9', ha='left', va='center')

        draw_figure(fig, ax)
        
        buf = io.BytesIO()
        fig.savefig(buf, format=format_type, dpi=dpi, bbox_inches='tight', pad_inches=0)
        buf.seek(0)
        
        data_uri = base64.b64encode(buf.getvalue()).decode()
        mime_type = 'image/png' if format_type == 'png' else 'application/pdf'
        outputs[format_type] = f"data:{mime_type};base64,{data_uri}"
        
        plt.close(fig)

    return outputs


def display_pdf(base64_pdf):
    """Generates the HTML to embed a PDF in Streamlit."""
    return f'<iframe src="{base64_pdf}" width="100%" height="800" type="application/pdf"></iframe>'

# --- Streamlit App ---
st.set_page_config(page_title="LED Screen Schedule Printer", layout="wide")
st.title("LED Screen Schedule Printer")

uploaded_file = st.file_uploader("Select the '放映时间核对表.xls' file", accept_multiple_files=False, type=["xls", "xlsx"])

if uploaded_file:
    with st.spinner("Processing file, please wait..."):
        schedule, date_str = process_schedule(uploaded_file)
        if schedule is not None and not schedule.empty:
            output = create_print_layout(schedule, date_str)
            
            tab1, tab2 = st.tabs(["PDF Preview", "PNG Preview"])
            
            with tab1:
                st.markdown(display_pdf(output['pdf']), unsafe_allow_html=True)
            
            with tab2:
                st.image(output['png'], use_container_width=True)
        else:
            st.error("Could not process the file. Please check if the file format and content are correct.")