"""
Automatic Time Table Generator (Improved)
- Gradio app for Hugging Face Spaces
- Exports: Word (.docx) and Text (.txt)
- Sunday = Holiday
- Languages: English, Sindhi, Urdu
"""

import io
import tempfile
import random
from typing import List, Dict
import gradio as gr
from docx import Document
from datetime import time, timedelta, datetime

# -------------------
# Localization labels
# -------------------
LANG = {
    "English": {
        "app_title": "Automatic Time Table Generator",
        "subtitle": "Generate timetables with subjects, teachers, rooms and period times.",
        "days_label": "Working days (comma-separated, omit Sunday; Sunday will be shown as Holiday)",
        "subjects_label": "Subjects (comma-separated, e.g. Math, English, Science)",
        "teachers_label": "Teachers (comma-separated, will cycle if fewer than subjects)",
        "rooms_label": "Rooms (comma-separated or single numbers, e.g. 1,2,3 ... 10)",
        "classes_label": "Class list (comma-separated, e.g. 1,2,3,4,5)",
        "periods_label": "Periods per day (integer)",
        "duration_label": "Period duration (hours, integer)",
        "start_label": "Start time (24h, e.g. 8 for 08:00)",
        "generate_btn": "Generate & Export (Word / Text)",
        "preview_label": "Generated Timetable Preview",
        "holiday_text": "Holiday",
        "word_label": "Download Word (.docx)",
        "text_label": "Download Text (.txt)",
        "doc_title": "Timetable"
    },
    "Sindhi": {
        "app_title": "خودڪار ٽائيم ٽيبل جنريٽر",
        "subtitle": "مضمون، استادن، ڪمري ۽ دورانيه سان ٽائيم ٽيبل ٺاهيو.",
        "days_label": "ڪم وارا ڏينهن (ڪاما سان الڳ، آچر شامل نه ڪريو؛ آچر موڪل ڏيکاريو ويندو)",
        "subjects_label": "مضمون (ڪاما سان الڳ ڪريو، مثال: Math, English, Science)",
        "teachers_label": "استاد (ڪاما سان الڳ ڪريو، جيڪڏهن گهٽ هجن ته ورجايا ويندا)",
        "rooms_label": "ڪمره (ڪاما سان يا انگ، مثال: 1,2,3 ... 10)",
        "classes_label": "ڪلاس لسٽ (ڪاما سان، مثال: 1,2,3,4,5)",
        "periods_label": "في ڏينهن دورا (عدد)",
        "duration_label": "هر دورو (گهنٽا)",
        "start_label": "شروعات جو وقت (24h، مثال: 8 لاءِ 08:00)",
        "generate_btn": "جنريٽ ۽ ٻاھ ڪڍو (Word / Text)",
        "preview_label": "پريوئو",
        "holiday_text": "موڪل",
        "word_label": "Word (.docx) ڊائونلوڊ ڪريو",
        "text_label": "Text (.txt) ڊائونلوڊ ڪريو",
        "doc_title": "ٽائيم ٽيبل"
    },
    "Urdu": {
        "app_title": "خودکار ٹائم ٹیبل جنریٹر",
        "subtitle": "مضامین، اساتذہ، کمروں اور دورانیوں کے ساتھ جدول بنائیں۔",
        "days_label": "کام کے دن (کاما سے جدا کریں، اتوار شامل نہ کریں؛ اتوار تعطیل دکھایا جائے گا)",
        "subjects_label": "مضامین (کاما سے جدا کریں، مثال: Math, English, Science)",
        "teachers_label": "اساتذہ (کاما سے جدا کریں، اگر کم ہوں گے تو دوبارہ آئیں گے)",
        "rooms_label": "کمروں کے نمبر (کاما سے یا نمبر، مثال: 1,2,3 ... 10)",
        "classes_label": "کلاس فہرست (کاما سے، مثال: 1,2,3,4,5)",
        "periods_label": "روزانہ دورانیے (عدد)",
        "duration_label": "ہر دورانیہ (گھنٹے)",
        "start_label": "شروع وقت (24h، مثال: 8 = 08:00)",
        "generate_btn": "جنریٹ کریں اور ایکسپورٹ کریں (Word / Text)",
        "preview_label": "پریویو",
        "holiday_text": "چھٹی",
        "word_label": "Word (.docx) ڈاؤن لوڈ کریں",
        "text_label": "Text (.txt) ڈاؤن لوڈ کریں",
        "doc_title": "ٹائم ٹیبل"
    }
}

HOLIDAY = "Sunday"

# -------------------
# Utilities
# -------------------
def parse_csv(s: str) -> List[str]:
    return [p.strip() for p in s.split(",") if p.strip()]

def ensure_days(days: List[str]) -> List[str]:
    # Normalize and ensure Sunday at end
    cleaned = []
    for d in days:
        d2 = d.strip().capitalize()
        if d2 and d2.lower() != HOLIDAY.lower():
            if d2 not in cleaned:
                cleaned.append(d2)
    cleaned.append(HOLIDAY)
    return cleaned

def compute_period_times(start_hour: int, duration_hours: int, periods: int) -> List[str]:
    times = []
    current = datetime(2000,1,1, start_hour, 0)
    delta = timedelta(hours=duration_hours)
    for _ in range(periods):
        end = current + delta
        times.append(f"{current.strftime('%H:%M')} - {end.strftime('%H:%M')}")
        current = end
    return times

# -------------------
# Timetable generation
# -------------------
def generate_timetable_for_class(days, subjects, teachers, rooms, period_times):
    """
    returns: dict day -> list of {time, subject, teacher, room}
    """
    mapping = {}
    # ensure rooms list has at least 1 item
    if not rooms:
        rooms = ["Room1"]
    if not teachers:
        teachers = ["TBD"]
    if not subjects:
        subjects = ["Free"]

    for day in days:
        if day.lower() == HOLIDAY.lower():
            mapping[day] = []  # Holiday marker
            continue

        # shuffle subjects for uniqueness
        order = subjects.copy()
        random.shuffle(order)

        day_slots = []
        for idx, t in enumerate(period_times):
            subj = order[idx % len(order)]
            teacher = teachers[idx % len(teachers)]
            room = rooms[idx % len(rooms)]
            day_slots.append({
                "time": t,
                "subject": subj,
                "teacher": teacher,
                "room": room
            })
        mapping[day] = day_slots
    return mapping

def generate_full_timetable(class_list, days, subjects, teachers, rooms, period_times):
    full = {}
    for cls in class_list:
        full[cls] = generate_timetable_for_class(days, subjects, teachers, rooms, period_times)
    return full

# -------------------
# Export helpers
# -------------------
def export_docx_bytes(full_tt: Dict[str, Dict], labels) -> str:
    """
    Create a temporary .docx file and return its path
    """
    doc = Document()
    doc.add_heading(labels["doc_title"], level=0)

    for cls, tt in full_tt.items():
        doc.add_heading(f"Class {cls}", level=1)
        for day, slots in tt.items():
            doc.add_heading(day, level=2)
            if not slots:
                doc.add_paragraph(labels["holiday_text"])
            else:
                table = doc.add_table(rows=1, cols=4)
                hdr = table.rows[0].cells
                hdr[0].text = "Time"
                hdr[1].text = "Subject"
                hdr[2].text = "Teacher"
                hdr[3].text = "Room"
                for s in slots:
                    row = table.add_row().cells
                    row[0].text = s["time"]
                    row[1].text = s["subject"]
                    row[2].text = s["teacher"]
                    row[3].text = s["room"]
                doc.add_paragraph("")  # small space

    tmp = tempfile.NamedTemporaryFile(delete=False, suffix=".docx")
    doc.save(tmp.name)
    tmp.close()
    return tmp.name

def export_text_bytes(full_tt: Dict[str, Dict], labels) -> str:
    lines = []
    for cls, tt in full_tt.items():
        lines.append(f"Class {cls}")
        lines.append("-" * (8 + len(str(cls))))
        for day, slots in tt.items():
            lines.append(f"{day}:")
            if not slots:
                lines.append(f"  {labels['holiday_text']}")
            else:
                for s in slots:
                    lines.append(f"  {s['time']} | {s['subject']} | {s['teacher']} | Room: {s['room']}")
        lines.append("")
    txt = "\n".join(lines)
    tmp = tempfile.NamedTemporaryFile(delete=False, suffix=".txt", mode="w", encoding="utf-8")
    tmp.write(txt)
    tmp.close()
    return tmp.name

# -------------------
# Main Gradio function
# -------------------
def build_and_export(
    language: str,
    days_input: str,
    subjects_input: str,
    teachers_input: str,
    rooms_input: str,
    classes_input: str,
    periods_per_day: int,
    duration_hours: int,
    start_hour: int,
    export_choice: str
):
    labels = LANG.get(language, LANG["English"])

    # parse inputs
    days = parse_csv(days_input)
    days = ensure_days(days)
    subjects = [s.strip() for s in parse_csv(subjects_input)]
    teachers = [t.strip() for t in parse_csv(teachers_input)]
    rooms = [r.strip() for r in parse_csv(rooms_input)] or [f"Room{i}" for i in range(1, 11)]
    class_list = [c.strip() for c in parse_csv(classes_input)] or ["1","2","3","4","5"]

    # validation
    if periods_per_day <= 0:
        return "⚠️ Periods per day must be a positive integer.", None, None

    if duration_hours <= 0:
        return "⚠️ Period duration must be a positive integer (hours).", None, None

    if start_hour < 0 or start_hour > 23:
        return "⚠️ Start hour must be between 0 and 23.", None, None

    period_times = compute_period_times(start_hour, duration_hours, periods_per_day)

    full_tt = generate_full_timetable(class_list, days, subjects, teachers, rooms, period_times)

    # Build preview text
    preview_lines = []
    for cls, tt in full_tt.items():
        preview_lines.append(f"Class {cls}")
        preview_lines.append("-" * (8 + len(str(cls))))
        for day, slots in tt.items():
            preview_lines.append(f"{day}:")
            if not slots:
                preview_lines.append(f"  {labels['holiday_text']}")
            else:
                for s in slots:
                    preview_lines.append(f"  {s['time']} | {s['subject']} | {s['teacher']} | Room: {s['room']}")
        preview_lines.append("")
    preview_text = "\n".join(preview_lines)

    # Exports
    docx_path = None
    txt_path = None
    if export_choice in ("Word", "Both"):
        docx_path = export_docx_bytes(full_tt, labels)
    if export_choice in ("Text", "Both"):
        txt_path = export_text_bytes(full_tt, labels)

    # return preview and file paths (Gradio File component accepts a filepath)
    # If a particular export wasn't requested, return None for its file output
    return preview_text, docx_path, txt_path

# -------------------
# Gradio UI
# -------------------
with gr.Blocks(title="Automatic Time Table Generator (Improved)") as demo:
    # Header
    with gr.Row():
        lang = gr.Dropdown(list(LANG.keys()), value="English", label="Language")
        gr.Markdown("<h2 style='margin-left:12px'>Automatic Time Table Generator (Improved)</h2>")

    with gr.Row():
        days_in = gr.Textbox(value="Monday, Tuesday, Wednesday, Thursday, Friday, Saturday", label=LANG["English"]["days_label"])
        classes_in = gr.Textbox(value="1,2,3,4,5", label=LANG["English"]["classes_label"])

    subjects_in = gr.Textbox(value="Math, English, Science, History, Art", label=LANG["English"]["subjects_label"])
    teachers_in = gr.Textbox(value="Mr. Ali, Ms. Fatima, Mr. Khan, Ms. Sara", label=LANG["English"]["teachers_label"])
    rooms_in = gr.Textbox(value="1,2,3,4,5,6,7,8,9,10", label=LANG["English"]["rooms_label"])

    with gr.Row():
        periods_in = gr.Number(value=6, label=LANG["English"]["periods_label"])
        duration_in = gr.Number(value=1, label=LANG["English"]["duration_label"])
        start_in = gr.Number(value=8, label=LANG["English"]["start_label"])

    export_choice = gr.Dropdown(choices=["Word", "Text", "Both"], value="Both", label="Export option")
    generate_btn = gr.Button(LANG["English"]["generate_btn"], variant="primary")

    preview = gr.Textbox(label=LANG["English"]["preview_label"], lines=20, interactive=False)
    download_docx = gr.File(label=LANG["English"]["word_label"])
    download_txt = gr.File(label=LANG["English"]["text_label"])

    # When language changes, update labels (client-side)
    def update_ui_labels(selected_lang):
        labels = LANG.get(selected_lang, LANG["English"])
        return (
            gr.update(label=labels["days_label"]),
            gr.update(label=labels["subjects_label"]),
            gr.update(label=labels["teachers_label"]),
            gr.update(label=labels["rooms_label"]),
            gr.update(label=labels["classes_label"]),
            gr.update(label=labels["periods_label"]),
            gr.update(label=labels["duration_label"]),
            gr.update(label=labels["start_label"]),
            gr.update(value=labels["generate_btn"]),
            gr.update(label=labels["preview_label"]),
            gr.update(label=labels["word_label"]),
            gr.update(label=labels["text_label"])
        )

    lang.change(
        fn=update_ui_labels,
        inputs=[lang],
        outputs=[days_in, subjects_in, teachers_in, rooms_in, classes_in, periods_in, duration_in, start_in, generate_btn, preview, download_docx, download_txt]
    )

    generate_btn.click(
        fn=build_and_export,
        inputs=[lang, days_in, subjects_in, teachers_in, rooms_in, classes_in, periods_in, duration_in, start_in, export_choice],
        outputs=[preview, download_docx, download_txt]
    )

if __name__ == "__main__":
    demo.launch(server_name="0.0.0.0", share=False)