"""
Smart Study Planner — Group H6
Hugging Face Gradio App
"""

import gradio as gr
import pandas as pd
import matplotlib.pyplot as plt
import matplotlib
matplotlib.use("Agg")
from datetime import datetime, date
import io

# ── OOP CLASSES (same logic as original app) ──────────────────

class User:
    def __init__(self, name):
        self.name = name

class Student(User):
    def __init__(self, name, level):
        super().__init__(name)
        self.level = level

class Task:
    def __init__(self, title, subject, deadline, difficulty, duration):
        self.title = title
        self.subject = subject
        self.deadline = deadline  # datetime.date object
        self.difficulty = difficulty.lower()
        self.duration = duration
        self.completed = False

    def mark_completed(self):
        self.completed = True

    def is_overdue(self):
        return self.deadline < date.today() and not self.completed

    def get_priority(self):
        days_left = (self.deadline - date.today()).days
        if days_left <= 1:
            p = 3
        elif days_left <= 3:
            p = 2
        else:
            p = 1
        if self.difficulty == "hard":
            p += 3
        elif self.difficulty == "medium":
            p += 2
        else:
            p += 1
        return p

class StudyPlanner:
    def __init__(self):
        self._tasks = []

    def add_task(self, task):
        self._tasks.append(task)

    def get_tasks(self):
        return self._tasks

    def remove_task(self, index):
        if 0 <= index < len(self._tasks):
            self._tasks.pop(index)

    def mark_completed(self, index):
        if 0 <= index < len(self._tasks):
            self._tasks[index].mark_completed()

    def to_dataframe(self):
        if not self._tasks:
            return pd.DataFrame()
        rows = []
        for i, t in enumerate(self._tasks):
            rows.append({
                "#": i + 1,
                "Title": t.title,
                "Subject": t.subject,
                "Deadline": str(t.deadline),
                "Difficulty": t.difficulty.capitalize(),
                "Hours": t.duration,
                "Priority": t.get_priority(),
                "Status": "✅ Done" if t.completed else ("🔴 Overdue" if t.is_overdue() else "🕐 Pending"),
                "Urgent": "⚠️ URGENT" if t.get_priority() >= 5 and not t.completed else "",
            })
        return pd.DataFrame(rows)

    def study_plan_df(self):
        pending = [t for t in self._tasks if not t.completed]
        if not pending:
            return pd.DataFrame()
        rows = []
        for t in pending:
            rows.append({
                "Title": t.title,
                "Subject": t.subject,
                "Deadline": str(t.deadline),
                "Difficulty": t.difficulty.capitalize(),
                "Hours": t.duration,
                "Priority Score": t.get_priority(),
                "Status": "🔴 OVERDUE" if t.is_overdue() else "🕐 Pending",
            })
        df = pd.DataFrame(rows)
        return df.sort_values("Priority Score", ascending=False).reset_index(drop=True)

    def plot_by_subject(self):
        if not self._tasks:
            return None
        subjects = [t.subject for t in self._tasks]
        counts = pd.Series(subjects).value_counts()
        fig, ax = plt.subplots(figsize=(8, 4))
        colors = plt.cm.Set3.colors[:len(counts)]
        counts.plot(kind="bar", ax=ax, color=colors, edgecolor="black")
        ax.set_title("Number of Tasks by Subject", fontsize=14, fontweight="bold")
        ax.set_xlabel("Subject")
        ax.set_ylabel("Count")
        ax.tick_params(axis="x", rotation=30)
        plt.tight_layout()
        return fig

# ── GLOBAL STATE ──────────────────────────────────────────────
planner = StudyPlanner()
student = None

# ── GRADIO FUNCTIONS ──────────────────────────────────────────

def set_student(name, level):
    global student
    if not name.strip():
        return "❌ Please enter your name.", ""
    student = Student(name.strip(), level)
    return f"👋 Welcome, **{student.name}** ({student.level})! You can now add your tasks below.", ""

def add_task(title, subject, deadline_str, difficulty, duration):
    if not title.strip() or not subject.strip():
        return "❌ Title and subject are required.", planner.to_dataframe()
    try:
        deadline = datetime.strptime(deadline_str, "%Y-%m-%d").date()
    except ValueError:
        return "❌ Invalid date. Use format YYYY-MM-DD.", planner.to_dataframe()
    try:
        dur = float(duration)
    except ValueError:
        return "❌ Duration must be a number.", planner.to_dataframe()

    task = Task(title.strip(), subject.strip(), deadline, difficulty, dur)
    planner.add_task(task)
    p = task.get_priority()
    alert = " ⚠️ **URGENT task!**" if p >= 5 else ""
    return f"✅ Task **'{title}'** added! Priority score: **{p}**.{alert}", planner.to_dataframe()

def view_tasks():
    df = planner.to_dataframe()
    if df.empty:
        return "No tasks yet. Add your first task above!", df
    urgent_count = sum(1 for t in planner.get_tasks() if t.get_priority() >= 5 and not t.completed)
    msg = f"📋 **{len(planner.get_tasks())} task(s)** total."
    if urgent_count:
        msg += f" ⚠️ **{urgent_count} urgent task(s)!**"
    return msg, df

def generate_plan():
    df = planner.study_plan_df()
    if df.empty:
        return "🎉 No pending tasks — you're all caught up!", df
    urgent = df[df["Priority Score"] >= 5]
    msg = f"📅 Study plan generated — **{len(df)} pending task(s)**, sorted by priority."
    if not urgent.empty:
        msg += f" ⚠️ **{len(urgent)} URGENT** (score ≥ 5)!"
    return msg, df

def mark_done(task_num_str):
    try:
        idx = int(task_num_str) - 1
        planner.mark_completed(idx)
        return f"✅ Task #{int(task_num_str)} marked as completed!", planner.to_dataframe()
    except (ValueError, IndexError):
        return "❌ Invalid task number.", planner.to_dataframe()

def remove_task(task_num_str):
    try:
        idx = int(task_num_str) - 1
        planner.remove_task(idx)
        return f"🗑️ Task #{int(task_num_str)} removed.", planner.to_dataframe()
    except (ValueError, IndexError):
        return "❌ Invalid task number.", planner.to_dataframe()

def show_chart():
    fig = planner.plot_by_subject()
    if fig is None:
        return None
    return fig

# ── UI ────────────────────────────────────────────────────────

with gr.Blocks(theme=gr.themes.Soft(), title="Smart Study Planner") as demo:
    gr.Markdown("""
    # 📚 Smart Study Planner
    **Group H6 — ESCP Business School**
    Manage your tasks, track priorities, and never miss a deadline.
    """)

    # ── SECTION 1: Student Setup
    with gr.Accordion("👤 Step 1 — Enter your details", open=True):
        with gr.Row():
            name_input = gr.Textbox(label="Your Name", placeholder="e.g. Julia")
            level_input = gr.Dropdown(
                choices=["Bachelor", "Master", "MBA", "PhD", "Other"],
                value="Master",
                label="Study Level"
            )
        welcome_btn = gr.Button("Start Planning →", variant="primary")
        welcome_msg = gr.Markdown("")

    welcome_btn.click(set_student, inputs=[name_input, level_input], outputs=[welcome_msg, gr.Textbox(visible=False)])

    # ── SECTION 2: Add Task
    with gr.Accordion("➕ Step 2 — Add a Task", open=True):
        with gr.Row():
            t_title = gr.Textbox(label="Task Title", placeholder="e.g. Chapter 5 Revision")
            t_subject = gr.Textbox(label="Subject", placeholder="e.g. Mathematics")
        with gr.Row():
            t_deadline = gr.Textbox(label="Deadline (YYYY-MM-DD)", placeholder=f"{date.today().strftime('%Y-%m-%d')}")
            t_difficulty = gr.Dropdown(choices=["Easy", "Medium", "Hard"], value="Medium", label="Difficulty")
            t_duration = gr.Number(label="Duration (hours)", value=2, minimum=0.5, maximum=20)
        add_btn = gr.Button("Add Task", variant="primary")
        add_msg = gr.Markdown("")

    task_table = gr.DataFrame(label="Your Tasks", wrap=True)
    add_btn.click(add_task, inputs=[t_title, t_subject, t_deadline, t_difficulty, t_duration], outputs=[add_msg, task_table])

    # ── SECTION 3: View / Plan / Actions
    with gr.Accordion("📋 Step 3 — View & Manage Tasks", open=False):
        with gr.Row():
            view_btn = gr.Button("🔍 View All Tasks")
            plan_btn = gr.Button("📅 Generate Study Plan", variant="primary")
        action_msg = gr.Markdown("")
        plan_table = gr.DataFrame(label="Study Plan / Task List", wrap=True)

        view_btn.click(view_tasks, outputs=[action_msg, plan_table])
        plan_btn.click(generate_plan, outputs=[action_msg, plan_table])

        gr.Markdown("---")
        with gr.Row():
            task_num_done = gr.Textbox(label="Task # to mark done", placeholder="e.g. 2")
            done_btn = gr.Button("✅ Mark as Completed")
            task_num_remove = gr.Textbox(label="Task # to remove", placeholder="e.g. 3")
            remove_btn = gr.Button("🗑️ Remove Task", variant="stop")

        done_msg = gr.Markdown("")
        done_table = gr.DataFrame(wrap=True)
        done_btn.click(mark_done, inputs=[task_num_done], outputs=[done_msg, done_table])
        remove_btn.click(remove_task, inputs=[task_num_remove], outputs=[done_msg, done_table])

    # ── SECTION 4: Chart
    with gr.Accordion("📊 Step 4 — Visualise Tasks by Subject", open=False):
        chart_btn = gr.Button("📊 Show Chart")
        chart_output = gr.Plot()
        chart_btn.click(show_chart, outputs=[chart_output])

    gr.Markdown("""
    ---
    **Priority Score Guide:**
    | Score | Meaning |
    |-------|---------|
    | 2 | Low priority — Easy + far deadline |
    | 4 | Medium priority |
    | 5–6 | ⚠️ URGENT — Act now! |

    *Built with Python + Gradio · Group H6 ESCP*
    """)

demo.launch()