use crate::params::chat::ChatCompletionParameters;
use anyhow::{Result, anyhow};
use minijinja::{Environment, Value as MiniJinjaValue, context};

use crate::utils::{extract_metadata_value, string_to_static_str};

pub fn fix_template(chat_template: &str) -> String {
    chat_template
        .replace(
            "content.startswith('<tool_response>')",
            "content is startingwith('<tool_response>')", // 使用minijinja中的 is startingwith 替换
        )
        .replace(
            "content.endswith('</tool_response>')",
            "content is endingwith('</tool_response>')", // 使用minijinja中的 is endingwith 替换
        )
        .replace(
            "content.split('</think>')[0].rstrip('\\n').split('<think>')[-1].lstrip('\\n')",
            "((content | split('</think>'))[0] | rstrip('\\n') | split('<think>'))[-1] | lstrip('\\n')", // 使用自定义的split, rstrip, lstrip过滤器替换
        )
        .replace(
            "content.split('</think>')[-1].lstrip('\\n')",
            "(content | split('</think>'))[-1] | lstrip('\\n')", // 使用自定义的过滤器替换
        )
        .replace(
            "reasoning_content.strip('\\n')",
            "reasoning_content | strip('\\n')", // 使用自定义的过滤器替换
        )
        .replace(
            "content.lstrip('\\n')",
            "content | lstrip('\\n')", // 使用自定义的过滤器替换
        )
}

pub fn get_template(path: String) -> Result<String> {
    let tokenizer_config_file = path.clone() + "/tokenizer_config.json";
    let chat_template = if std::path::Path::new(&tokenizer_config_file).exists() {
        let tokenizer_config: serde_json::Value =
            serde_json::from_slice(&std::fs::read(tokenizer_config_file)?)
                .map_err(|e| anyhow!(format!("load tokenizer_config file error:{}", e)))?;
        let chat_template = tokenizer_config["chat_template"]
            .as_str()
            .map(|s| s.to_string());
        let chat_template = match chat_template {
            Some(tem) => Some(tem),
            None => {
                let chat_template_file = path.clone() + "/chat_template.json";
                if std::path::Path::new(&chat_template_file).exists() {
                    let chat_template_config: serde_json::Value =
                        serde_json::from_slice(&std::fs::read(chat_template_file)?)
                            .map_err(|e| anyhow!(format!("load chat_template file error:{}", e)))?;
                    chat_template_config["chat_template"]
                        .as_str()
                        .map(|s| s.to_string())
                } else {
                    None
                }
            }
        };
        match chat_template {
            Some(tem) => Some(tem),
            None => {
                let jinja_path = path + "/chat_template.jinja";
                if std::path::Path::new(&jinja_path).exists() {
                    let temp = std::fs::read_to_string(&jinja_path)
                        .map_err(|e| anyhow!("Failed to read chat_template.jinja: {}", e))?;
                    Some(temp)
                } else {
                    None
                }
            }
        }
    } else {
        None
    };
    let chat_template = chat_template.ok_or(anyhow!(format!("chat_template is none")))?;
    // 修复模板中的问题行
    let fixed_template = fix_template(&chat_template);
    Ok(fixed_template)
}

pub struct ChatTemplate<'a> {
    env: Environment<'a>,
}

impl<'a> ChatTemplate<'a> {
    fn setup_environment(env: &mut Environment<'a>) {
        env.add_filter("tojson", |v: MiniJinjaValue| {
            serde_json::to_string(&v).unwrap()
        });

        env.add_filter("split", |s: String, delimiter: String| {
            s.split(&delimiter)
                .map(|s| s.to_string())
                .collect::<Vec<String>>()
        });

        env.add_filter("lstrip", |s: String, chars: Option<String>| match chars {
            Some(chars_str) => s.trim_start_matches(chars_str.as_str()).to_string(),
            None => s.trim_start().to_string(),
        });

        env.add_filter("rstrip", |s: String, chars: Option<String>| match chars {
            Some(chars_str) => s.trim_end_matches(chars_str.as_str()).to_string(),
            None => s.trim_end().to_string(),
        });
    }
    pub fn init(path: &str) -> Result<Self> {
        let path: String = path.to_string();
        if !std::path::Path::new(&path).exists() {
            return Err(anyhow!("model path not found"));
        }
        let template = get_template(path.clone())?;
        let template = string_to_static_str(template);
        // 加载jinjaenv处理chat_template
        let mut env = Environment::new();
        Self::setup_environment(&mut env);
        let _ = env.add_template("chat", template);

        Ok(Self { env })
    }

    pub fn str_init(chat_template: &str) -> Result<Self> {
        let fixed_template = fix_template(chat_template);
        let template = string_to_static_str(fixed_template);
        // 加载jinjaenv处理chat_template
        let mut env = Environment::new();
        Self::setup_environment(&mut env);
        let _ = env.add_template("chat", template);

        Ok(Self { env })
    }

    pub fn apply_chat_template(&self, messages: &ChatCompletionParameters) -> Result<String> {
        let enable_thinking = extract_metadata_value::<bool>(&messages.metadata, "enable_thinking");
        let context = context! {
            messages => &messages.messages,
            tools => &messages.tools.as_ref(),
            add_generation_prompt => true,
            enable_thinking => enable_thinking,
        };
        let template = self
            .env
            .get_template("chat")
            .map_err(|e| anyhow!(format!("render template error {}", e)))?;
        let message_str = template
            .render(context)
            .map_err(|e| anyhow!(format!("render template error {}", e)))?;
        Ok(message_str)
    }
}