// SPDX-FileCopyrightText: Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
// SPDX-License-Identifier: Apache-2.0

pub mod base_json_parser;
pub mod deepseek_v3_1_parser;
pub mod deepseek_v3_parser;

pub use super::{config, response};
pub use base_json_parser::{detect_tool_call_start_basic_json, try_tool_call_parse_basic_json};
pub use deepseek_v3_1_parser::{
    detect_tool_call_start_deepseek_v3_1, parse_tool_calls_deepseek_v3_1,
};
pub use deepseek_v3_parser::{detect_tool_call_start_deepseek_v3, parse_tool_calls_deepseek_v3};

pub use super::config::JsonParserConfig;
pub use super::response::ToolCallResponse;

#[derive(Clone, Debug, serde::Serialize, serde::Deserialize, Default)]
pub enum JsonParserType {
    // Basic is generic json parser which can handle most of the cases
    #[default]
    Basic,
    // Model Specific JSON Parsers
    DeepseekV3,
    DeepseekV31,
}

pub fn try_tool_call_parse_json(
    message: &str,
    config: &JsonParserConfig,
    tools: Option<&[super::ToolDefinition]>,
) -> anyhow::Result<(Vec<ToolCallResponse>, Option<String>)> {
    match config.parser_type {
        JsonParserType::Basic => try_tool_call_parse_basic_json(message, config, tools),
        JsonParserType::DeepseekV3 => parse_tool_calls_deepseek_v3(message, config, tools),
        JsonParserType::DeepseekV31 => parse_tool_calls_deepseek_v3_1(message, config, tools),
    }
}

pub fn detect_tool_call_start_json(chunk: &str, config: &JsonParserConfig) -> bool {
    match config.parser_type {
        JsonParserType::Basic => detect_tool_call_start_basic_json(chunk, config),
        JsonParserType::DeepseekV3 => detect_tool_call_start_deepseek_v3(chunk, config),
        JsonParserType::DeepseekV31 => detect_tool_call_start_deepseek_v3_1(chunk, config),
    }
}

pub fn find_tool_call_end_position_json(
    chunk: &str,
    parser: &str,
    config: &JsonParserConfig,
) -> usize {
    match parser {
        "hermes" | "nemotron_deci" => {
            let start_token = config.tool_call_start_tokens.first().map(|s| s.as_str());
            if let Some(end_token) = config.tool_call_end_tokens.first() {
                let Some(first_end) = chunk.find(end_token.as_str()) else {
                    return chunk.len();
                };
                let mut cursor = first_end + end_token.len();

                // Advance past any additional consecutive start→end blocks
                // so that parallel tool calls are captured as one jailed region.
                if let Some(start_tok) = start_token {
                    loop {
                        let rest = &chunk[cursor..];
                        let trimmed = rest.trim_start();
                        if !trimmed.starts_with(start_tok) {
                            break;
                        }
                        let trim_offset = rest.len() - trimmed.len();
                        let search_from = cursor + trim_offset + start_tok.len();
                        if let Some(end_pos) = chunk[search_from..].find(end_token.as_str()) {
                            cursor = search_from + end_pos + end_token.len();
                        } else {
                            break;
                        }
                    }
                }
                cursor
            } else {
                chunk.len()
            }
        }
        "mistral" | "phi4" => {
            if let Some(pos) = chunk.rfind(']') {
                pos + 1
            } else {
                chunk.len()
            }
        }
        _ => chunk.len(),
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    /// Regression test for issue #6822: parallel tool calls in a single chunk must
    /// all be captured by find_tool_call_end_position_json so that the jail passes the
    /// entire group to the parser rather than emitting the second (and later) calls
    /// as raw trailing text.
    #[test]
    fn test_find_tool_call_end_position_parallel_calls() {
        let config = JsonParserConfig {
            tool_call_start_tokens: vec!["<tool_call>".to_string()],
            tool_call_end_tokens: vec!["</tool_call>".to_string()],
            ..Default::default()
        };

        // Two parallel calls with no whitespace between them.
        let two_calls = concat!(
            "<tool_call>{\"name\": \"foo\", \"arguments\": {\"x\": 1}}</tool_call>",
            "<tool_call>{\"name\": \"bar\", \"arguments\": {\"y\": 2}}</tool_call>",
            "trailing"
        );
        let pos = find_tool_call_end_position_json(two_calls, "hermes", &config);
        assert!(
            two_calls[..pos].ends_with("</tool_call>"),
            "should end at last </tool_call>, got: {:?}",
            &two_calls[..pos]
        );
        assert_eq!(&two_calls[pos..], "trailing");

        // Three parallel calls separated by whitespace / newlines.
        let three_calls = concat!(
            "<tool_call>{\"name\": \"a\"}</tool_call>\n",
            "<tool_call>{\"name\": \"b\"}</tool_call>\n",
            "<tool_call>{\"name\": \"c\"}</tool_call> done"
        );
        let pos3 = find_tool_call_end_position_json(three_calls, "hermes", &config);
        assert!(
            three_calls[..pos3].ends_with("</tool_call>"),
            "should end at last </tool_call>, got: {:?}",
            &three_calls[..pos3]
        );
        assert_eq!(three_calls[pos3..].trim(), "done");

        // Incomplete second call — should stop after the first complete one.
        let incomplete = concat!(
            "<tool_call>{\"name\": \"a\"}</tool_call>",
            "<tool_call>{\"name\": \"b\""
        );
        let pos_inc = find_tool_call_end_position_json(incomplete, "hermes", &config);
        let first_end = "<tool_call>{\"name\": \"a\"}</tool_call>".len();
        assert_eq!(
            pos_inc, first_end,
            "should stop at end of first complete call when second is incomplete"
        );
    }
}