app.py

# app.py
"""Minimal Flask blog with file-based JSON storage.

Features:
- Display all posts
- Add / Update / Delete posts
- Like posts
- JSON API endpoints

Run:
    pip install flask
    python app.py
"""
from __future__ import annotations

from typing import Any, Dict

from flask import (
    Flask,
    abort,
    jsonify,
    redirect,
    render_template,
    request,
    url_for,
)

import storage  # JSON storage helper for posts.json

app = Flask(__name__)


# ---------------------------- Pages -----------------------------------------
@app.get("/")
def index():
    """Render the index page with all posts."""
    posts = storage.load_posts()
    return render_template("index.html", posts=posts)


@app.route("/add", methods=["GET", "POST"])
def add():
    """Render and handle the add-post form."""
    if request.method == "POST":
        author = (request.form.get("author") or "").strip()
        title = (request.form.get("title") or "").strip()
        content = (request.form.get("content") or "").strip()

        if not author or not title or not content:
            return (
                render_template(
                    "add.html",
                    error="All fields are required.",
                    form={
                        "author": author,
                        "title": title,
                        "content": content,
                    },
                ),
                400,
            )

        storage.add_post(author, title, content)
        return redirect(url_for("index"))

    return render_template("add.html")


@app.route("/update/<int:post_id>", methods=["GET", "POST"])
def update(post_id: int):
    """Render and handle the update-post form."""
    post = storage.get_post(post_id)
    if not post:
        abort(404, description="Post not found")

    if request.method == "POST":
        author = (request.form.get("author") or "").strip()
        title = (request.form.get("title") or "").strip()
        content = (request.form.get("content") or "").strip()

        if not author or not title or not content:
            # Re-render with the values the user just submitted
            return (
                render_template(
                    "update.html",
                    error="All fields are required.",
                    post={
                        "id": post_id,
                        "author": author,
                        "title": title,
                        "content": content,
                    },
                ),
                400,
            )

        storage.update_post(post_id, author=author, title=title, content=content)
        return redirect(url_for("index"))

    # GET -> show form prefilled with current post
    return render_template("update.html", post=post)


@app.route("/delete/<int:post_id>")
def delete(post_id: int):
    """Delete a post by ID and redirect to index."""
    ok = storage.delete_post(post_id)
    if not ok:
        abort(404, description="Post not found")
    return redirect(url_for("index"))


@app.route("/like/<int:post_id>")
def like(post_id: int):
    """Increment like counter for a post and redirect to index."""
    updated = storage.like_post(post_id)
    if not updated:
        abort(404, description="Post not found")
    return redirect(url_for("index"))


# ----------------------------- JSON API -------------------------------------
@app.get("/health")
def health():
    """Lightweight health endpoint."""
    return jsonify(status="ok")


@app.get("/posts")
def list_posts():
    """Return all posts as JSON."""
    return jsonify(storage.load_posts())


@app.get("/posts/<int:post_id>")
def get_post(post_id: int):
    """Return a single post as JSON or 404."""
    post = storage.get_post(post_id)
    if not post:
        abort(404, description="Post not found")
    return jsonify(post)


@app.post("/posts")
def create_post():
    """Create a post from JSON body."""
    data: Dict[str, Any] = request.get_json(silent=True) or {}
    author = data.get("author")
    title = data.get("title")
    content = data.get("content")

    if not all([author, title, content]):
        abort(400, description="author, title, and content are required")

    new_post = storage.add_post(str(author), str(title), str(content))
    return jsonify(new_post), 201


@app.patch("/posts/<int:post_id>")
def patch_post(post_id: int):
    """Partially update a post by ID."""
    data: Dict[str, Any] = request.get_json(silent=True) or {}
    updated = storage.update_post(
        post_id,
        author=data.get("author"),
        title=data.get("title"),
        content=data.get("content"),
    )
    if not updated:
        abort(404, description="Post not found")
    return jsonify(updated)


@app.delete("/posts/<int:post_id>")
def remove_post(post_id: int):
    """Delete a post by ID via API."""
    ok = storage.delete_post(post_id)
    if not ok:
        abort(404, description="Post not found")
    return jsonify({"deleted": post_id})


if __name__ == "__main__":
    # Bind on all interfaces for local containers/dev; use a non-privileged port.
    app.run(host="0.0.0.0", port=4999, debug=True)