import asyncio
from typing import Optional

from fastapi import HTTPException
from llmai import get_client
from llmai.shared import JSONSchemaResponse, Message, SystemMessage, UserMessage
from models.presentation_layout import PresentationLayoutModel
from models.presentation_outline_model import PresentationOutlineModel
from utils.llm_config import get_llm_config
from utils.llm_client_error_handler import handle_llm_client_exceptions
from utils.llm_utils import extract_structured_content, get_generate_kwargs
from utils.llm_provider import get_model
from utils.get_dynamic_models import get_presentation_structure_model_with_n_slides
from models.presentation_structure_model import PresentationStructureModel


STRUCTURE_FROM_SLIDES_MARKDOWN_SYSTEM_PROMPT = """
You will be given available slide layouts and content for each slide.
You need to select a layout for each slide based on the mentioned guidelines.

# Steps
1. Analyze all available slide layouts.
2. Analyze content for each slide.
3. Select a layout for each slide one by one by following the selection rules.

# Analyzing Slide Layouts
- Identify what each layout contains based on provided schema markdown.

# Analyzing Content
- Identify how the content is structured.
- Identify if the content contains tables.

# Selection Rules
- If content contains table, then select either table layout or graph layout.
- Don't select layout with image unless content contains image.
- Don't select table layout if content does not contain table.
- You are allowed to select same layout for multiple slides.

# Table Layout Selection Rules
- Must select table layout if the content contains table with text data.
- Must only select a layout with table if the table only contains text data.

# Graph Layout Selection Rules
- Must only select a layout with chart if the content contains table with numeric data.
- Identify how many columns are present in the table.
- Must select a layout that supports n-1 charts for n columns.
- Must prioritize layouts that support multiple charts.
- Don't select metrics layout for content containing table with numeric data.
- For example, if content contains table with 3 columns, then select a layout that supports 2 charts.

{user_instructions}

# Output Rules: 
- One layout index for each slide.
- Example: [0, 1, 2, 3, 4]

{presentation_layout}
"""


GET_MESSAGES_SYSTEM_PROMPT = """
You're a professional presentation designer with creative freedom to design engaging presentations.

# DESIGN PHILOSOPHY
- Create visually compelling and varied presentations
- Match layout to content purpose and audience needs

# Layout Selection Guidelines
1. **Content-driven choices**: Let the slide's purpose guide layout selection
- Opening/closing → Title layouts
- Processes/workflows → Visual process layouts  
- Comparisons/contrasts → Side-by-side layouts
- Data/metrics → Chart/graph layouts
- Concepts/ideas → Image + text layouts
- Key insights → Emphasis layouts

2. **Visual variety**: Aim for diverse slide layouts across the presentation. 
- Don't use same layout for multiple slides unless necessary.
- Mix text-heavy and visual-heavy slides naturally
- Use your judgment on when repetition serves the content
- Balance information density across slides
- Adjacent slide layouts should be different unless instructed/necessary otherwise.

3. **Audience experience**: Consider how slides work together
- Create natural transitions between topics

4. **Table of contents**:
- Must only use table of contents layout if slide content contains table of contents.

{user_instruction_header}

User instruction should be taken into account while creating the presentation structure, except for number of slides.

Select layout index for each of the {n_slides} slides based on what will best serve the presentation's goals.

"""


def get_messages(
    presentation_layout: PresentationLayoutModel,
    n_slides: int,
    data: str,
    instructions: Optional[str] = None,
) -> list[Message]:
    system_prompt = GET_MESSAGES_SYSTEM_PROMPT.format(
        user_instruction_header="# User Instruction:" if instructions else "",
        n_slides=n_slides,
    )

    return [
        SystemMessage(content=system_prompt),
        UserMessage(
            content=(
                f"{presentation_layout.to_string()}\n\n"
                "--------------------------------------\n\n"
                f"{data}"
            )
        ),
    ]


def get_messages_for_slides_markdown(
    presentation_layout: PresentationLayoutModel,
    n_slides: int,
    data: str,
    instructions: Optional[str] = None,
) -> list[Message]:
    system_prompt = STRUCTURE_FROM_SLIDES_MARKDOWN_SYSTEM_PROMPT.format(
        user_instructions=instructions or "",
        presentation_layout=presentation_layout.to_string(with_schema=True),
    )

    return [SystemMessage(content=system_prompt), UserMessage(content=data)]


async def generate_presentation_structure(
    presentation_outline: PresentationOutlineModel,
    presentation_layout: PresentationLayoutModel,
    instructions: Optional[str] = None,
    using_slides_markdown: bool = False,
) -> PresentationStructureModel:
    client = get_client(config=get_llm_config())
    model = get_model()
    response_model = get_presentation_structure_model_with_n_slides(
        len(presentation_outline.slides)
    )

    try:
        messages = (
            get_messages_for_slides_markdown(
                presentation_layout,
                len(presentation_outline.slides),
                presentation_outline.to_string(),
                instructions,
            )
            if using_slides_markdown
            else get_messages(
                presentation_layout,
                len(presentation_outline.slides),
                presentation_outline.to_string(),
                instructions,
            )
        )
        response_format = JSONSchemaResponse(
            name="response",
            json_schema=response_model.model_json_schema(),
            strict=True,
        )

        for attempt in range(3):
            response = await asyncio.to_thread(
                client.generate,
                **get_generate_kwargs(
                    model=model,
                    messages=messages,
                    response_format=response_format,
                ),
            )
            content = extract_structured_content(response.content)
            if content is not None:
                return PresentationStructureModel(**content)

            if attempt < 2:
                await asyncio.sleep(0.5 * (attempt + 1))

        raise HTTPException(status_code=400, detail="LLM did not return any content")
    except Exception as e:
        raise handle_llm_client_exceptions(e)