import math
import re
from datetime import datetime
from typing import Optional


from open_webui.utils.misc import get_last_user_message, get_messages_content


def prompt_template(
    template: str, user_name: Optional[str] = None, user_location: Optional[str] = None
) -> str:
    # Get the current date
    current_date = datetime.now()

    # Format the date to YYYY-MM-DD
    formatted_date = current_date.strftime("%Y-%m-%d")
    formatted_time = current_date.strftime("%I:%M:%S %p")

    template = template.replace("{{CURRENT_DATE}}", formatted_date)
    template = template.replace("{{CURRENT_TIME}}", formatted_time)
    template = template.replace(
        "{{CURRENT_DATETIME}}", f"{formatted_date} {formatted_time}"
    )

    if user_name:
        # Replace {{USER_NAME}} in the template with the user's name
        template = template.replace("{{USER_NAME}}", user_name)
    else:
        # Replace {{USER_NAME}} in the template with "Unknown"
        template = template.replace("{{USER_NAME}}", "Unknown")

    if user_location:
        # Replace {{USER_LOCATION}} in the template with the current location
        template = template.replace("{{USER_LOCATION}}", user_location)
    else:
        # Replace {{USER_LOCATION}} in the template with "Unknown"
        template = template.replace("{{USER_LOCATION}}", "Unknown")

    return template


def replace_prompt_variable(template: str, prompt: str) -> str:
    def replacement_function(match):
        full_match = match.group(0)
        start_length = match.group(1)
        end_length = match.group(2)
        middle_length = match.group(3)

        if full_match == "{{prompt}}":
            return prompt
        elif start_length is not None:
            return prompt[: int(start_length)]
        elif end_length is not None:
            return prompt[-int(end_length) :]
        elif middle_length is not None:
            middle_length = int(middle_length)
            if len(prompt) <= middle_length:
                return prompt
            start = prompt[: math.ceil(middle_length / 2)]
            end = prompt[-math.floor(middle_length / 2) :]
            return f"{start}...{end}"
        return ""

    template = re.sub(
        r"{{prompt}}|{{prompt:start:(\d+)}}|{{prompt:end:(\d+)}}|{{prompt:middletruncate:(\d+)}}",
        replacement_function,
        template,
    )
    return template


def title_generation_template(
    template: str, prompt: str, user: Optional[dict] = None
) -> str:
    template = replace_prompt_variable(template, prompt)
    template = prompt_template(
        template,
        **(
            {"user_name": user.get("name"), "user_location": user.get("location")}
            if user
            else {}
        ),
    )

    return template


def replace_messages_variable(template: str, messages: list[str]) -> str:
    def replacement_function(match):
        full_match = match.group(0)
        start_length = match.group(1)
        end_length = match.group(2)
        middle_length = match.group(3)

        # Process messages based on the number of messages required
        if full_match == "{{MESSAGES}}":
            return get_messages_content(messages)
        elif start_length is not None:
            return get_messages_content(messages[: int(start_length)])
        elif end_length is not None:
            return get_messages_content(messages[-int(end_length) :])
        elif middle_length is not None:
            mid = int(middle_length)

            if len(messages) <= mid:
                return get_messages_content(messages)
            # Handle middle truncation: split to get start and end portions of the messages list
            half = mid // 2
            start_msgs = messages[:half]
            end_msgs = messages[-half:] if mid % 2 == 0 else messages[-(half + 1) :]
            formatted_start = get_messages_content(start_msgs)
            formatted_end = get_messages_content(end_msgs)
            return f"{formatted_start}\n{formatted_end}"
        return ""

    template = re.sub(
        r"{{MESSAGES}}|{{MESSAGES:START:(\d+)}}|{{MESSAGES:END:(\d+)}}|{{MESSAGES:MIDDLETRUNCATE:(\d+)}}",
        replacement_function,
        template,
    )

    return template


def search_query_generation_template(
    template: str, messages: list[dict], user: Optional[dict] = None
) -> str:
    prompt = get_last_user_message(messages)
    template = replace_prompt_variable(template, prompt)
    template = replace_messages_variable(template, messages)

    template = prompt_template(
        template,
        **(
            {"user_name": user.get("name"), "user_location": user.get("location")}
            if user
            else {}
        ),
    )
    return template


def moa_response_generation_template(
    template: str, prompt: str, responses: list[str]
) -> str:
    def replacement_function(match):
        full_match = match.group(0)
        start_length = match.group(1)
        end_length = match.group(2)
        middle_length = match.group(3)

        if full_match == "{{prompt}}":
            return prompt
        elif start_length is not None:
            return prompt[: int(start_length)]
        elif end_length is not None:
            return prompt[-int(end_length) :]
        elif middle_length is not None:
            middle_length = int(middle_length)
            if len(prompt) <= middle_length:
                return prompt
            start = prompt[: math.ceil(middle_length / 2)]
            end = prompt[-math.floor(middle_length / 2) :]
            return f"{start}...{end}"
        return ""

    template = re.sub(
        r"{{prompt}}|{{prompt:start:(\d+)}}|{{prompt:end:(\d+)}}|{{prompt:middletruncate:(\d+)}}",
        replacement_function,
        template,
    )

    responses = [f'"""{response}"""' for response in responses]
    responses = "\n\n".join(responses)

    template = template.replace("{{responses}}", responses)
    return template


def tools_function_calling_generation_template(template: str, tools_specs: str) -> str:
    template = template.replace("{{TOOLS}}", tools_specs)
    return template