from dataclasses import dataclass, field
from datetime import datetime
from typing import Any, Dict, List


@dataclass
class StatsModel:
    """Class that models the output of the Tumblr stats script."""
    # The operation that was used to output stats.
    operation: str

    # The blog in question.
    blog_name: str

    # Contains original posts, indexed by post ID.
    original_post_map: Dict[str, Any]

    # Contains posts that are not original, indexed by post ID.
    unoriginal_post_map: Dict[str, Any]

    # Any tags used.
    tags: List[str] = field(default_factory=list)

    # Total count of posts processed.
    total_posts: int = field(init=False)

    # Total original posts (for blog_name) processed.
    total_original_posts: int = field(init=False)

    # Total original post (for blog_name) notes processed.
    total_original_post_notes: int = field(init=False)

    # Total notes for original posts within each month and year.
    total_original_post_notes_by_month_and_year: Dict[str, int] = field(
        init=False)

    def __post_init__(self):
        self.total_posts = self.calculate_total_posts()
        self.total_original_posts = self.calculate_total_original_posts()
        self.total_original_post_notes = self.calculate_total_original_post_notes()
        self.total_original_post_notes_by_month_and_year = self.calculate_total_original_post_notes_by_month_and_year()

    def calculate_total_posts(self) -> int:
        return len(self.original_post_map) + len(self.unoriginal_post_map)

    def calculate_total_original_posts(self) -> int:
        return len(self.original_post_map)

    def calculate_total_original_post_notes(self) -> int:
        total = 0
        for post_key in self.original_post_map:
            total += self.original_post_map[post_key]['note_count']
        return total

    def calculate_total_original_post_notes_by_month_and_year(self) -> Dict[str, int]:
        date_map: Dict[str, int] = {}
        for post_key in self.original_post_map:
            post = self.original_post_map[post_key]
            # Format is like 2025-12-28 20:00:34 GMT
            post_date: datetime = datetime.strptime(
                post['date'], '%Y-%m-%d %H:%M:%S %Z')
            post_date_key = f"{post_date.year}-{post_date.month:02}"
            if post_date_key in date_map:
                date_map[post_date_key] += post['note_count']
            else:
                date_map[post_date_key] = post['note_count']
        return date_map