"""Storybook Generator Application.

This application generates a children's storybook using the OpenAI API.

The user can select a theme, specify the main character's name, and choose a
setting. The app generates a 10-page storybook with images.

The tech stack is: Python, Ludic, and HTMX. All of the code is in
this single file.

"""

# : out storybook
# : dep ludic
# : dep openai
# : dep uvicorn
# : dep starlette
# : dep sqids
# : dep requests
# : dep types-requests
import json
import logging
import ludic
import ludic.catalog.buttons as buttons
import ludic.catalog.forms as forms
import ludic.catalog.headers as headers
import ludic.catalog.layouts as layouts
import ludic.catalog.pages as pages
import ludic.catalog.typography as typography
import ludic.web
import Omni.Log as Log
import openai
import pathlib
import requests
import sqids
import starlette.testclient
import sys
import time
import typing
import unittest
import uvicorn

MOCK = True
DEBUG = False
DATA_DIR = pathlib.Path("_/var/storybook/")

app = ludic.web.LudicApp(debug=DEBUG)
Sqids = sqids.Sqids()


def main() -> None:
    """Run the Ludic application."""
    if sys.argv[1] == "test":
        test()
    else:
        move()


def move() -> None:
    """Run the application."""
    Log.setup(logging.DEBUG if DEBUG else logging.ERROR)
    local = "127.0.0.1"
    uvicorn.run(app, host=local)


def test() -> None:
    """Run the unittest suite manually."""
    Log.setup(logging.DEBUG if DEBUG else logging.ERROR)
    suite = unittest.TestSuite()
    tests = [StorybookTest, IndexTest, StoryTest, ImagesTest]
    suite.addTests([
        unittest.defaultTestLoader.loadTestsFromTestCase(tc) for tc in tests
    ])
    unittest.TextTestRunner(verbosity=2).run(suite)


def const(s: str) -> str:
    """Just returns the input."""
    return s


class PageContent(ludic.attrs.Attrs):
    """Represents the content of a single page in the storybook."""

    image_prompt: str
    text: str


class Page(ludic.attrs.Attrs):
    """Represents a single page in the storybook."""

    story_id: str
    page_number: int
    content: PageContent


class Image(ludic.attrs.Attrs):
    """Represents an image associated with a story page."""

    story_id: str
    page: int
    prompt: typing.Annotated[str, const]
    original_url: typing.Annotated[str, const]
    path: pathlib.Path


class Prompt(ludic.attrs.Attrs):
    """Represents a prompt for generating an image."""

    text: typing.Annotated[str, const]


class StoryInputs(ludic.attrs.Attrs):
    """Represents story inputs from the user."""

    theme: typing.Annotated[str, const]
    character: typing.Annotated[str, const]
    setting: typing.Annotated[str, const]
    moral: typing.Annotated[str, const]


example_story: dict[str, str] = {
    "theme": "Christian",
    "character": "Lia and her pet bunny",
    "setting": "A suburban park",
    "moral": "Honor thy mother and father",
}


class Story(ludic.attrs.Attrs):
    """Represents a full generated story."""

    id: typing.Annotated[str, const]
    pages: typing.Annotated[list[Page], const]


system_prompt: str = (
    "You are an author and illustrator of childrens books. "
    "Each book is 10 pages long. "
    "All output must be in valid JSON. "
    "Don't add explanation or markdown formatting beyond the JSON. "
    "In your output, include the text on the page and a description of the "
    "image to be generated with an AI image generator."
)


def user_prompt(story: StoryInputs) -> str:
    """Generate the user prompt based on the story details."""
    return " ".join([
        "Write a story with the following details.",
        "Output must be in valid JSON where each page is an array of text and"
        "image like the following example:",
        """[{"text": "<text of the story>",""",
        """"image": "<description of illustration>"}...],""",
        f"Character: {story['character']}\n",
        f"Setting: {story['setting']}\n",
        f"Theme: {story['theme']}\n",
        f"Moral: {story['moral']}\n",
    ])


def _openai_generate_text(
    story: StoryInputs,
) -> openai.types.chat.ChatCompletion:
    """Generate story text using the OpenAI API."""
    messages: list[
        openai.types.chat.ChatCompletionUserMessageParam
        | openai.types.chat.ChatCompletionSystemMessageParam
    ] = [
        {"role": "system", "content": system_prompt},
        {"role": "user", "content": user_prompt(story)},
    ]
    client = openai.OpenAI()
    return client.chat.completions.create(
        model="gpt-4o-mini",
        messages=messages,
        max_tokens=1500,
    )


def generate_pages(inputs: StoryInputs) -> list[PageContent]:
    """Generate the text for a story and update its pages.

    Raises:
        ValueError: when openAI response is bad
    """
    # when developing, don't run up the OpenAI tab
    if MOCK:
        name = inputs["character"]
        return [
            PageContent(
                text=f"A story about {name}...",
                image_prompt="Lorem ipsum..",
            )
            for n in range(10)
        ]
    response = _openai_generate_text(inputs)
    content = response.choices[0].message.content
    if content is None:
        msg = "content is none"
        raise ValueError(msg)
    response_messages = json.loads(content)
    return [
        PageContent(
            text=msg["text"],
            image_prompt=msg["image"],
        )
        for msg in response_messages
    ]


class StoryTest(unittest.TestCase):
    """Unit test case for the Story class and related functions."""

    def test_story_creation(self) -> None:
        """Creates a story with 10 pages."""
        s = StoryInputs(example_story)  # type: ignore[misc]
        pages = generate_pages(s)
        self.assertIsNotNone(pages)
        self.assertEqual(len(pages), 10)


class AppPage(
    ludic.components.Component[ludic.types.AnyChildren, ludic.attrs.NoAttrs],
):
    """HTML wrapper for the app."""

    @typing.override
    def render(self) -> pages.HtmlPage:
        return pages.HtmlPage(
            pages.Head(
                ludic.html.meta(charset="utf-8"),
                ludic.html.meta(
                    name="viewport",
                    content="width=device-width, initial-scale=1",
                ),
                ludic.html.style.load(),
                title="Storybook",
                favicon="favicon.ico",
                load_styles=True,
            ),
            pages.Body(
                layouts.Center(layouts.Stack(*self.children)),
                htmx_version="latest",
            ),
        )


@app.get("/")
def index(_: ludic.web.Request) -> AppPage:
    """Render the main page."""
    return AppPage(
        headers.H1("Storybook Generator"),
        StoriesForm(),
        ludic.html.div(id="story"),
    )


class IndexTest(unittest.TestCase):
    """Test the home page."""

    def setUp(self) -> None:
        """Create test client."""
        self.client = starlette.testclient.TestClient(app)

    def test_index(self) -> None:
        """The index page loads successfully."""
        response = self.client.get("/")
        self.assertEqual(response.status_code, 200)
        self.assertIn("Storybook Generator", response.text)


db_last_story_id: str = "bM"  # sqid.encode([0])


class Database(ludic.attrs.Attrs):
    """Represents a simple in-memory database for storing stories and images."""

    stories: dict[str, Story]
    images: dict[str, Image]


db: Database = Database(stories={}, images={})


@app.endpoint("/pages/{story_id:str}/{page:int}")
class Pages(ludic.web.Endpoint[Page]):
    """Resource for retrieving individual pages in a story."""

    @classmethod
    def get(cls, story_id: str, page: int) -> typing.Self:
        """Get a single page."""
        story = Stories.get(story_id)
        story_page = Page(**story.attrs["pages"][page])
        return cls(**story_page)

    @typing.override
    def render(self) -> ludic.base.BaseElement:
        """Render a single page as HTML."""
        return layouts.Box(
            layouts.Stack(
                ludic.html.img(
                    src="//placehold.co/256/000000/FFFFFF",
                    hx_post=app.url_path_for(
                        "Images",
                        story_id=self.attrs["story_id"],
                        page=self.attrs["page_number"],
                    ),
                    hx_trigger="load",
                    hx_swap="outerHTML:beforeend",
                    hx_vals=json.dumps(
                        Prompt(text=self.attrs["content"]["image_prompt"]),
                    ),
                    width=256,
                    height=256,
                ),
                typography.Paragraph(self.attrs["content"]["text"]),
            ),
        )


@app.endpoint("/images/{story_id:str}/{page:int}")
class Images(ludic.web.Endpoint[Image]):
    """Endpoint for handling image-related operations."""

    @classmethod
    def get(cls, story_id: str, page: int) -> ludic.web.responses.Response:
        """Load the image from the database, if not found return 404.

        Raises:
            NotFoundError: If the image is not found.
        """
        if image := Images.load_by_id(story_id, page):
            return ludic.web.responses.FileResponse(image["path"])
        msg = "no image found"
        logging.error(msg)
        raise ludic.web.exceptions.NotFoundError(msg)

    @classmethod
    def post(
        cls,
        story_id: str,
        page: int,
        data: ludic.web.parsers.Parser[Prompt],
    ) -> ludic.web.responses.Response:
        """Create a new image, or retrieve an existing one."""
        Prompt(**data.validate())
        path = cls.gen_path(story_id, page)
        if path.exists():
            return cls.get(story_id, page)
        return cls.put(story_id, page, data)

    @classmethod
    def put(
        cls,
        story_id: str,
        page: int,
        data: ludic.web.parsers.Parser[Prompt],
    ) -> ludic.web.responses.Response:
        """Create a new image, overwriting if one exists.

        Raises:
            InternalServerError: If there is an error getting the image from the
                OpenAI API.
        """
        if MOCK:
            # Simulate slow image generation
            time.sleep(3)
            return ludic.web.responses.FileResponse(
                DATA_DIR / "images" / "placeholder.jpg",
            )
        client = openai.OpenAI()
        prompt = Prompt(**data.validate())
        image_response = client.images.generate(
            prompt=prompt["text"],
            n=1,
            size="256x256",
        )
        url = image_response.data[0].url
        if url is None:
            msg = "error getting image from OpenAI"
            logging.error(msg)
            raise ludic.web.exceptions.InternalServerError(msg)
        image = Image(
            story_id=story_id,
            page=page,
            prompt=prompt["text"],
            original_url=url,
            path=cls.gen_path(story_id, page),
        )
        cls.save(image)
        return ludic.web.responses.FileResponse(image["path"])

    @classmethod
    def gen_image_id(cls, story_id: str, page: int) -> str:
        """Generate a unique image ID based on the story ID and page number."""
        story_id_num = Sqids.decode(story_id)[0]
        return Sqids.encode([story_id_num, page])

    @classmethod
    def load_by_id(cls, story_id: str, page: int) -> Image | None:
        """Load an image by its story ID and page number."""
        cls.gen_image_id(story_id, page)
        path = cls.gen_path(story_id, page)
        if path.exists():
            return Image(
                story_id=story_id,
                page=page,
                path=path,
                # Consider storing prompt and original_url in sqlite
                prompt="",
                original_url="",
            )
        return None

    @classmethod
    def gen_path(cls, story_id: str, page: int) -> pathlib.Path:
        """Generate the file path for an image."""
        image_id = cls.gen_image_id(story_id, page)
        return pathlib.Path(
            DATA_DIR / "images" / story_id / image_id,
        ).with_suffix(".jpg")

    @classmethod
    def save(cls, image: Image) -> None:
        """Save an image to the file system."""
        response = requests.get(image["original_url"], timeout=10)
        pathlib.Path(image["path"]).write_bytes(response.content)

    @classmethod
    def read(cls, image: Image) -> bytes:
        """Read an image from the file system."""
        return pathlib.Path(image["path"]).read_bytes()

    @typing.override
    def render(self) -> ludic.base.BaseElement:
        return ludic.html.img(
            src=app.url_path_for(
                "Images",
                story_id=self.attrs["story_id"],
                page=self.attrs["page"],
            ),
        )


class ImagesTest(unittest.TestCase):
    """Test the Images endpoint."""

    def setUp(self) -> None:
        """Create test client."""
        self.client = starlette.testclient.TestClient(app)

    def test_image_post(self) -> None:
        """Can POST an Image successfully."""
        response = self.client.post(
            app.url_path_for(
                "Images",
                story_id="Uk",
                page=1,
            ),
            data={"text": "lorem ipsum"},
        )
        self.assertEqual(response.status_code, 200)


@app.endpoint("/stories/{story_id:str}")
class Stories(ludic.web.Endpoint[Story]):
    """Resource for accessing a Story."""

    @classmethod
    def get(cls, story_id: str) -> typing.Self:
        """Get a single story.

        Raises:
            NotFoundError: if the story doesn't exist.
        """
        story = db["stories"].get(story_id)
        if story is None:
            msg = f"story {story_id} not found"
            raise ludic.web.exceptions.NotFoundError(msg)
        return cls(**story)

    @classmethod
    def put(cls, story_id: str, data: list[PageContent]) -> typing.Self:
        """Upsert a new story."""
        pages = [
            Page(story_id=story_id, page_number=n, content=page_content)
            for n, page_content in enumerate(data)
        ]
        story = Story(id=story_id, pages=pages)
        # save to the 'database'
        db["stories"][story_id] = story
        return cls(**story)

    @typing.override
    def render(self) -> ludic.base.BaseElement:
        return layouts.Stack(
            headers.H1(str(self.attrs["id"])),
            *(Pages(**page) for page in self.attrs["pages"]),
        )


@app.endpoint("/stories")
class StoriesForm(ludic.web.Endpoint[StoryInputs]):
    """Form for generating new stories."""

    @classmethod
    def post(cls, data: ludic.web.parsers.Parser[StoryInputs]) -> Stories:
        """Upsert a new story."""
        inputs = StoryInputs(**data.validate())
        # generate story pages
        # Consider calling Pages.put for each one after generating the text
        pages = generate_pages(inputs)
        # calculate sqid
        next_id_num = 1 + Sqids.decode(db_last_story_id)[0]
        next_id = Sqids.encode([next_id_num])
        return Stories.put(next_id, pages)

    @typing.override
    def render(self) -> ludic.base.BaseElement:
        """Render the story as HTML."""
        return layouts.Box(
            forms.Form(
                forms.SelectField(
                    forms.Option("Christian", value="Christian"),
                    forms.Option("Secular", value="Secular"),
                    id="theme",
                    name="theme",
                    label="Select Theme:",
                    for_="theme",
                ),
                forms.InputField(
                    label="Main Character's Name:",
                    for_="character",
                    type="text",
                    id="character",
                    name="character",
                    required=True,
                    value="Alice",
                ),
                forms.SelectField(
                    forms.Option("Rural", value="rural"),
                    forms.Option("Urban", value="urban"),
                    forms.Option("Beach", value="beach"),
                    forms.Option("Forest", value="forest"),
                    label="Select Setting:",
                    for_="setting",
                    id="setting",
                    name="setting",
                ),
                forms.InputField(
                    label="Moral:",
                    for_="moral",
                    type="text",
                    id="moral",
                    name="moral",
                    required=True,
                    value="Honor thy mother and father",
                ),
                buttons.ButtonSuccess(
                    "Generate Story",
                    type="submit",
                    classes=["large"],
                ),
                hx_post=self.url_for(StoriesForm),
                hx_target="#story",
            ),
        )


class StorybookTest(unittest.TestCase):
    """Unit test case for the Storybook application."""

    def setUp(self) -> None:
        """Set up the test client and seed database."""
        self.client = starlette.testclient.TestClient(app)
        self.character = "Alice"
        self.data = example_story | {"character": self.character}
        self.client.post("/stories/", data=self.data)
        self.story = next(iter(db["stories"].values()))
        self.story_id = self.story["id"]

    def test_stories_post(self) -> None:
        """User can create a story."""
        response = self.client.post("/stories/", data=self.data)
        self.assertEqual(response.status_code, 200)
        self.assertIn(self.character, response.text)

    def test_stories_post_invalid_data(self) -> None:
        """Invalid POST data."""
        response = self.client.post(
            app.url_path_for("StoriesForm"),
            data={"bad": "data"},
        )
        self.assertNotEqual(response.status_code, 200)

    def test_stories_get(self) -> None:
        """User can access the story directly."""
        response = self.client.get(
            app.url_path_for("Stories", story_id=self.story_id),
        )
        self.assertEqual(response.status_code, 200)
        self.assertIn(self.character, response.text)

    def test_stories_get_nonexistent(self) -> None:
        """Returns 404 when a story is not found."""
        response = self.client.get(
            app.url_path_for("Stories", story_id="nonexistent"),
        )
        self.assertEqual(response.status_code, 404)

    def test_pages_get(self) -> None:
        """User can access one page at a time."""
        page_num = 1
        _story = self.story["pages"][page_num]
        response = self.client.get(
            app.url_path_for("Pages", story_id=self.story_id, page=page_num),
        )
        self.assertEqual(response.status_code, 200)
        self.assertIn(self.character, response.text)


if __name__ == "__main__":
    main()