from os.path import exists
from typing import Literal, Optional, Union

import numpy as np
from dynamicprompts.generators import CombinatorialPromptGenerator, RandomPromptGenerator
from pydantic import validator

from invokeai.app.invocations.primitives import StringCollectionOutput

from .baseinvocation import BaseInvocation, InputField, InvocationContext, UIComponent, tags, title


@title("Dynamic Prompt")
@tags("prompt", "collection")
class DynamicPromptInvocation(BaseInvocation):
    """Parses a prompt using adieyal/dynamicprompts' random or combinatorial generator"""

    type: Literal["dynamic_prompt"] = "dynamic_prompt"

    # Inputs
    prompt: str = InputField(description="The prompt to parse with dynamicprompts", ui_component=UIComponent.Textarea)
    max_prompts: int = InputField(default=1, description="The number of prompts to generate")
    combinatorial: bool = InputField(default=False, description="Whether to use the combinatorial generator")

    def invoke(self, context: InvocationContext) -> StringCollectionOutput:
        if self.combinatorial:
            generator = CombinatorialPromptGenerator()
            prompts = generator.generate(self.prompt, max_prompts=self.max_prompts)
        else:
            generator = RandomPromptGenerator()
            prompts = generator.generate(self.prompt, num_images=self.max_prompts)

        return StringCollectionOutput(collection=prompts)


@title("Prompts from File")
@tags("prompt", "file")
class PromptsFromFileInvocation(BaseInvocation):
    """Loads prompts from a text file"""

    type: Literal["prompt_from_file"] = "prompt_from_file"

    # Inputs
    file_path: str = InputField(description="Path to prompt text file")
    pre_prompt: Optional[str] = InputField(
        default=None, description="String to prepend to each prompt", ui_component=UIComponent.Textarea
    )
    post_prompt: Optional[str] = InputField(
        default=None, description="String to append to each prompt", ui_component=UIComponent.Textarea
    )
    start_line: int = InputField(default=1, ge=1, description="Line in the file to start start from")
    max_prompts: int = InputField(default=1, ge=0, description="Max lines to read from file (0=all)")

    @validator("file_path")
    def file_path_exists(cls, v):
        if not exists(v):
            raise ValueError(FileNotFoundError)
        return v

    def promptsFromFile(
        self,
        file_path: str,
        pre_prompt: Union[str, None],
        post_prompt: Union[str, None],
        start_line: int,
        max_prompts: int,
    ):
        prompts = []
        start_line -= 1
        end_line = start_line + max_prompts
        if max_prompts <= 0:
            end_line = np.iinfo(np.int32).max
        with open(file_path) as f:
            for i, line in enumerate(f):
                if i >= start_line and i < end_line:
                    prompts.append((pre_prompt or "") + line.strip() + (post_prompt or ""))
                if i >= end_line:
                    break
        return prompts

    def invoke(self, context: InvocationContext) -> StringCollectionOutput:
        prompts = self.promptsFromFile(
            self.file_path, self.pre_prompt, self.post_prompt, self.start_line, self.max_prompts
        )
        return StringCollectionOutput(collection=prompts)