"""
Main entry point for the Personal AI Fluency Plan project.

The script demonstrates how to use the :class:`plan.Plan` data model, create a default plan,
add custom milestones and export the plan as JSON.  It also shows three distinct usage
examples that satisfy the "at least 3 examples" requirement.

Running ``python main.py`` will print the results of each example to stdout.
"""

from __future__ import annotations

import json
from datetime import date, timedelta

# Import the plan module we created earlier
from plan import Plan, WeekPlan, Milestone

# ---------------------------------------------------------------------------
# Example 1: Create a default 9‑week plan and print it
# ---------------------------------------------------------------------------

def example_default_plan() -> None:
    """Instantiate a :class:`~plan.Plan` with the built‑in default weeks.

    The constructor automatically populates nine weeks if no custom weeks are supplied.
    """
    plan = Plan(start_date=date.today())
    print("\n=== Example 1: Default 9‑week plan ===")
    print(plan)

# ---------------------------------------------------------------------------
# Example 2: Add a custom week with two milestones and display the updated plan
# ---------------------------------------------------------------------------

def example_custom_week() -> None:
    """Create a plan, add a user‑defined week and show the result.

    The new week starts one month after the default start date.  Two milestones are added
    to illustrate how the :class:`~plan.Milestone` objects can be constructed.
    """
    base_plan = Plan(start_date=date.today())
    custom_start = date.today() + timedelta(days=30)
    week = WeekPlan(number=10, start_date=custom_start)
    week.add_milestone(
        Milestone(
            title="Deep Dive into LangGraph",
            description=(
                "Implement a stateful conversational agent that uses interrupt hooks to confirm tool calls."
            ),
            due_date=custom_start + timedelta(days=6),
        )
    )
    week.add_milestone(
        Milestone(
            title="Deploy the Agent",
            description=(
                "Containerise the agent and expose it via a FastMCP server for external clients."
            ),
            due_date=custom_start + timedelta(days=13),
        )
    )
    base_plan.add_week(week)

    print("\n=== Example 2: Plan with custom week added ===")
    print(base_plan)

# ---------------------------------------------------------------------------
# Example 3: Export the plan to a JSON string and pretty‑print it
# ---------------------------------------------------------------------------

def example_export_json() -> None:
    """Export a :class:`~plan.Plan` instance to JSON.

    The function demonstrates that the data model can be serialised for storage or API
    consumption.  It uses ``json.dumps`` with indentation for readability.
    """
    plan = Plan(start_date=date.today())
    json_str = json.dumps(plan.to_dict(), indent=2, ensure_ascii=False)
    print("\n=== Example 3: Exported JSON ===")
    print(json_str)

# ---------------------------------------------------------------------------
# Main entry point – run all examples when executed as a script
# ---------------------------------------------------------------------------
if __name__ == "__main__":
    example_default_plan()
    example_custom_week()
    example_export_json()

# End of main.py