from flask import Flask, jsonify, request, render_template
from datetime import datetime
import uuid

app = Flask(__name__)

# In-memory task store (no DB needed — works out of the box)
tasks = {}

def make_task(title, priority="medium", due_date=None, category="general"):
    return {
        "id": str(uuid.uuid4())[:8],
        "title": title,
        "priority": priority,        # low | medium | high
        "category": category,
        "due_date": due_date,
        "done": False,
        "created_at": datetime.now().strftime("%Y-%m-%d %H:%M"),
    }

# Seed with sample tasks
for t in [
    make_task("Design the landing page", "high", "2026-06-25", "work"),
    make_task("Buy groceries", "low", "2026-06-22", "personal"),
    make_task("Review pull request #42", "high", "2026-06-23", "work"),
    make_task("Read Clean Code book", "medium", "2026-06-30", "learning"),
    make_task("Call the dentist", "medium", "2026-06-24", "personal"),
]:
    tasks[t["id"]] = t


# ── HTML ──────────────────────────────────────────────────────────────────────

@app.route("/")
def index():
    return render_template("index.html")


# ── REST API ──────────────────────────────────────────────────────────────────

@app.route("/api/tasks", methods=["GET"])
def get_tasks():
    filter_done = request.args.get("done")
    filter_priority = request.args.get("priority")
    filter_category = request.args.get("category")

    result = list(tasks.values())

    if filter_done is not None:
        result = [t for t in result if t["done"] == (filter_done == "true")]
    if filter_priority:
        result = [t for t in result if t["priority"] == filter_priority]
    if filter_category:
        result = [t for t in result if t["category"] == filter_category]

    # Sort: undone first, then by priority
    priority_order = {"high": 0, "medium": 1, "low": 2}
    result.sort(key=lambda t: (t["done"], priority_order.get(t["priority"], 9)))

    return jsonify({"tasks": result, "total": len(result)})


@app.route("/api/tasks", methods=["POST"])
def create_task():
    data = request.get_json() or {}
    title = data.get("title", "").strip()
    if not title:
        return jsonify({"error": "Title is required"}), 400

    task = make_task(
        title=title,
        priority=data.get("priority", "medium"),
        due_date=data.get("due_date"),
        category=data.get("category", "general"),
    )
    tasks[task["id"]] = task
    return jsonify(task), 201


@app.route("/api/tasks/<task_id>", methods=["PATCH"])
def update_task(task_id):
    task = tasks.get(task_id)
    if not task:
        return jsonify({"error": "Task not found"}), 404

    data = request.get_json() or {}
    for field in ("title", "priority", "due_date", "category", "done"):
        if field in data:
            task[field] = data[field]

    return jsonify(task)


@app.route("/api/tasks/<task_id>", methods=["DELETE"])
def delete_task(task_id):
    if task_id not in tasks:
        return jsonify({"error": "Task not found"}), 404
    del tasks[task_id]
    return jsonify({"deleted": task_id})


@app.route("/api/stats", methods=["GET"])
def stats():
    all_tasks = list(tasks.values())
    return jsonify({
        "total": len(all_tasks),
        "done": sum(1 for t in all_tasks if t["done"]),
        "pending": sum(1 for t in all_tasks if not t["done"]),
        "high_priority": sum(1 for t in all_tasks if t["priority"] == "high" and not t["done"]),
    })


if __name__ == "__main__":
    print("\n  TaskMaster running → http://127.0.0.1:5000\n")
    app.run(debug=True)