use std::collections::BTreeMap;

use forge_json_repair::json_repair;
use serde::{Deserialize, Serialize};
use serde_json::value::RawValue;
use serde_json::{Map, Value};

use crate::Error;

#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ToolCallArguments {
    Unparsed(String),
    Parsed(Value),
}

impl Serialize for ToolCallArguments {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: serde::Serializer,
    {
        match self {
            ToolCallArguments::Unparsed(value) => {
                // Use RawValue to serialize the JSON string without double serialization
                match RawValue::from_string(value.clone()) {
                    Ok(raw) => raw.serialize(serializer),
                    Err(_) => value.serialize(serializer), // Fallback if not valid JSON
                }
            }
            ToolCallArguments::Parsed(value) => value.serialize(serializer),
        }
    }
}
impl<'de> Deserialize<'de> for ToolCallArguments {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        let value = Value::deserialize(deserializer)?;

        // Handle case where API sends arguments as a string containing JSON
        // e.g., "{\"key\": \"value\"}" instead of {"key": "value"}
        if let Value::String(json_str) = &value {
            if let Ok(repaired) = json_repair(json_str) {
                return Ok(ToolCallArguments::Parsed(repaired));
            }
            // If json_repair fails, fall back to storing as Unparsed
            return Ok(ToolCallArguments::Unparsed(json_str.clone()));
        }

        Ok(ToolCallArguments::Parsed(value))
    }
}

impl Default for ToolCallArguments {
    fn default() -> Self {
        ToolCallArguments::Parsed(Value::Object(Map::new()))
    }
}

impl ToolCallArguments {
    pub fn into_string(self) -> String {
        match self {
            ToolCallArguments::Unparsed(str) => str,
            ToolCallArguments::Parsed(value) => value.to_string(),
        }
    }

    /// Normalizes the arguments by converting `Unparsed` strings into
    /// structured JSON values when possible.
    ///
    /// This is used for persisted conversations that may contain tool call
    /// arguments saved as raw strings. If repair succeeds, the arguments become
    /// `Parsed`. If repair fails, the raw content is preserved inside a
    /// fallback object so downstream request builders always receive
    /// structured JSON.
    pub fn normalize(self) -> Self {
        match self {
            ToolCallArguments::Unparsed(json_str) => {
                // Try to parse the string as JSON
                if let Ok(repaired) = json_repair(&json_str) {
                    ToolCallArguments::Parsed(repaired)
                } else {
                    // If it's not valid JSON, create a fallback object with the raw content
                    // This ensures we always send valid JSON to the API
                    let mut map = Map::new();
                    map.insert("_raw_content".to_string(), Value::String(json_str));
                    ToolCallArguments::Parsed(Value::Object(map))
                }
            }
            ToolCallArguments::Parsed(_) => self,
        }
    }

    pub fn parse(&self) -> Result<Value, Error> {
        match self {
            ToolCallArguments::Unparsed(json) => {
                Ok(
                    json_repair(json).map_err(|error| crate::Error::ToolCallArgument {
                        error,
                        args: json.to_owned(),
                    })?,
                )
            }
            ToolCallArguments::Parsed(value) => Ok(value.to_owned()),
        }
    }

    pub fn from_json(str: &str) -> Self {
        ToolCallArguments::Unparsed(str.to_string())
    }

    pub fn from_parameters(object: BTreeMap<String, String>) -> ToolCallArguments {
        let mut map = Map::new();

        for (key, value) in object {
            map.insert(key, convert_string_to_value(&value));
        }

        ToolCallArguments::Parsed(Value::Object(map))
    }
}

fn convert_string_to_value(value: &str) -> Value {
    // Try to parse as boolean first
    match value.trim().to_lowercase().as_str() {
        "true" => return Value::Bool(true),
        "false" => return Value::Bool(false),
        _ => {}
    }

    // Try to parse as number
    if let Ok(int_val) = value.parse::<i64>() {
        return Value::Number(int_val.into());
    }

    if let Ok(float_val) = value.parse::<f64>() {
        // Create number from float, handling special case where float is actually an
        // integer
        return if float_val.fract() == 0.0 {
            Value::Number(serde_json::Number::from(float_val as i64))
        } else if let Some(num) = serde_json::Number::from_f64(float_val) {
            Value::Number(num)
        } else {
            Value::String(value.to_string())
        };
    }

    // Default to string if no other type matches
    Value::String(value.to_string())
}

impl From<Value> for ToolCallArguments {
    fn from(value: Value) -> Self {
        ToolCallArguments::Parsed(value)
    }
}

#[cfg(test)]
mod tests {
    use pretty_assertions::assert_eq;
    use serde_json::json;

    use super::*;

    #[test]
    fn test_serialize_unparsed_valid_json() {
        let fixture = ToolCallArguments::from_json(r#"{"param": "value", "count": 42}"#);
        let actual = serde_json::to_string(&fixture).unwrap();
        // The RawValue preserves the original JSON string when it's valid
        let expected = r#"{"param": "value", "count": 42}"#;
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_serialize_unparsed_valid_json_array() {
        let fixture = ToolCallArguments::from_json(r#"["item1", "item2", 123]"#);
        let actual = serde_json::to_string(&fixture).unwrap();
        // The RawValue preserves the original JSON string when it's valid
        let expected = r#"["item1", "item2", 123]"#;
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_serialize_unparsed_valid_json_nested() {
        let fixture = ToolCallArguments::from_json(
            r#"{"user": {"name": "John", "settings": {"theme": "dark"}}}"#,
        );
        let actual = serde_json::to_string(&fixture).unwrap();
        // The RawValue preserves the original JSON string when it's valid
        let expected = r#"{"user": {"name": "John", "settings": {"theme": "dark"}}}"#;
        assert_eq!(actual, expected);
    }
    #[test]
    fn test_serialize_unparsed_valid_json_compact() {
        let fixture = ToolCallArguments::from_json(r#"{"param":"value","count":42}"#);
        let actual = serde_json::to_string(&fixture).unwrap();
        // The RawValue preserves the original JSON string when it's valid
        let expected = r#"{"param":"value","count":42}"#;
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_serialize_unparsed_invalid_json() {
        let fixture = ToolCallArguments::from_json(r#"{"param": "value", invalid}"#);
        let actual = serde_json::to_string(&fixture).unwrap();
        let expected = r#""{\"param\": \"value\", invalid}""#;
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_serialize_unparsed_malformed_json() {
        let fixture = ToolCallArguments::from_json("not json at all");
        let actual = serde_json::to_string(&fixture).unwrap();
        let expected = r#""not json at all""#;
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_deserialize_stringified_json_object() {
        // Simulates kimi-k2p5-turbo sending "arguments": "{\"key\": \"value\"}"
        // The outer quotes make it a JSON string, inside we have escaped JSON
        let json_str = r#""{\"file_path\": \"/test\", \"content\": \"hello\"}""#;
        let actual: ToolCallArguments = serde_json::from_str(json_str).unwrap();
        let expected = ToolCallArguments::Parsed(json!({
            "file_path": "/test",
            "content": "hello"
        }));
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_roundtrip_stringified_json() {
        // Start with stringified JSON, deserialize, then serialize back
        let original = r#""{\"param\": \"value\", \"count\": 42}""#;
        let deserialized: ToolCallArguments = serde_json::from_str(original).unwrap();

        // After roundtrip, should be a proper JSON object (not a string)
        let serialized = serde_json::to_string(&deserialized).unwrap();
        let reparsed: Value = serde_json::from_str(&serialized).unwrap();

        // Should be an object, not a string
        assert!(
            reparsed.is_object(),
            "Should be JSON object, got: {}",
            serialized
        );
        assert_eq!(reparsed["param"], "value");
        assert_eq!(reparsed["count"], 42);
    }

    #[test]
    fn test_serialize_unparsed_empty_string() {
        let fixture = ToolCallArguments::from_json("");
        let actual = serde_json::to_string(&fixture).unwrap();
        // Empty string is not valid JSON, so it falls back to string serialization
        // which produces a JSON string (quoted)
        assert_eq!(actual, "\"\"");
    }

    #[test]
    fn test_serialize_parsed_object() {
        let fixture = ToolCallArguments::Parsed(json!({
            "name": "test",
            "value": 42,
            "enabled": true
        }));
        let actual = serde_json::to_string(&fixture).unwrap();
        let expected = r#"{"enabled":true,"name":"test","value":42}"#;
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_serialize_parsed_array() {
        let fixture = ToolCallArguments::Parsed(json!(["a", "b", 123, true, null]));
        let actual = serde_json::to_string(&fixture).unwrap();
        let expected = r#"["a","b",123,true,null]"#;
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_serialize_parsed_primitive_string() {
        let fixture = ToolCallArguments::Parsed(json!("simple string"));
        let actual = serde_json::to_string(&fixture).unwrap();
        let expected = r#""simple string""#;
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_serialize_parsed_primitive_number() {
        let fixture = ToolCallArguments::Parsed(json!(42));
        let actual = serde_json::to_string(&fixture).unwrap();
        let expected = "42";
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_serialize_parsed_primitive_boolean() {
        let fixture = ToolCallArguments::Parsed(json!(true));
        let actual = serde_json::to_string(&fixture).unwrap();
        let expected = "true";
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_serialize_parsed_null() {
        let fixture = ToolCallArguments::Parsed(json!(null));
        let actual = serde_json::to_string(&fixture).unwrap();
        let expected = "null";
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_deserialize_valid_json_object() {
        let json_str = r#"{"param": "value", "count": 42}"#;
        let actual: ToolCallArguments = serde_json::from_str(json_str).unwrap();
        let expected = ToolCallArguments::Parsed(json!({
            "param": "value",
            "count": 42
        }));
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_deserialize_valid_json_array() {
        let json_str = r#"["item1", "item2", 123]"#;
        let actual: ToolCallArguments = serde_json::from_str(json_str).unwrap();
        let expected = ToolCallArguments::Parsed(json!(["item1", "item2", 123]));
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_deserialize_primitive_string() {
        let json_str = r#""simple string""#;
        let actual: ToolCallArguments = serde_json::from_str(json_str).unwrap();
        let expected = ToolCallArguments::Parsed(json!("simple string"));
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_roundtrip_unparsed_valid_json() {
        let original_json = r#"{"param": "value", "count": 42}"#;
        let fixture = ToolCallArguments::from_json(original_json);
        let serialized = serde_json::to_string(&fixture).unwrap();
        let deserialized: ToolCallArguments = serde_json::from_str(&serialized).unwrap();
        let expected = ToolCallArguments::Parsed(json!({
            "param": "value",
            "count": 42
        }));
        assert_eq!(deserialized, expected);
    }

    #[test]
    fn test_roundtrip_parsed_value() {
        let fixture = ToolCallArguments::Parsed(json!({
            "name": "test",
            "value": 42,
            "enabled": true
        }));
        let serialized = serde_json::to_string(&fixture).unwrap();
        let actual: ToolCallArguments = serde_json::from_str(&serialized).unwrap();
        let expected = fixture;
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_parse_unparsed_valid_json() {
        let fixture = ToolCallArguments::from_json(r#"{"param": "value"}"#);
        let actual = fixture.parse().unwrap();
        let expected = json!({"param": "value"});
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_parse_unparsed_invalid_json_with_repair() {
        let fixture = ToolCallArguments::from_json(r#"{"param": "value", "missing_quote": true"#);
        let actual = fixture.parse().unwrap();
        let expected = json!({"param": "value", "missing_quote": true});
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_parse_parsed_value() {
        let value = json!({"param": "value"});
        let fixture = ToolCallArguments::Parsed(value.clone());
        let actual = fixture.parse().unwrap();
        let expected = value;
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_from_parameters() {
        let mut params = BTreeMap::new();
        params.insert("name".to_string(), "John".to_string());
        params.insert("age".to_string(), "30".to_string());
        params.insert("active".to_string(), "true".to_string());
        params.insert("score".to_string(), "95.5".to_string());

        let actual = ToolCallArguments::from_parameters(params);
        let expected = ToolCallArguments::Parsed(json!({
            "name": "John",
            "age": 30,
            "active": true,
            "score": 95.5
        }));
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_normalize_unparsed_json_string() {
        // Test that stringified JSON gets normalized to Parsed
        let fixture = ToolCallArguments::from_json(r#"{"file_path": "/test", "content": "hello"}"#);
        let normalized = fixture.normalize();

        // Should be converted to Parsed
        match normalized {
            ToolCallArguments::Parsed(value) => {
                assert_eq!(value["file_path"], "/test");
                assert_eq!(value["content"], "hello");
            }
            ToolCallArguments::Unparsed(_) => panic!("Should be Parsed after normalization"),
        }
    }

    #[test]
    fn test_normalize_parsed_value_unchanged() {
        // Test that already Parsed values stay as Parsed
        let fixture = ToolCallArguments::Parsed(json!({"key": "value"}));
        let normalized = fixture.normalize();

        match normalized {
            ToolCallArguments::Parsed(value) => assert_eq!(value["key"], "value"),
            ToolCallArguments::Unparsed(_) => panic!("Should remain Parsed"),
        }
    }

    #[test]
    fn test_normalize_malformed_json_from_dump() {
        // Test the exact malformed JSON from the kimi dump
        let fixture = ToolCallArguments::from_json(r#"{" ,"replace_all": false}"#);
        let normalized = fixture.normalize();

        // When JSON can't be repaired, it should create a fallback object
        match normalized {
            ToolCallArguments::Parsed(value) => {
                // Should contain the raw content in a fallback object
                assert!(
                    value.get("_raw_content").is_some(),
                    "Expected fallback object with _raw_content, got: {:?}",
                    value
                );
            }
            ToolCallArguments::Unparsed(_) => {
                panic!("Should be Parsed (with fallback) even for malformed JSON")
            }
        }
    }

    #[test]
    fn test_normalize_real_kimi_string() {
        // Test with a realistic kimi-k2p5-turbo stringified argument
        let json_str = r#"{"file_path": "/home/kassie/projects/test.ts", "new_string": "import { parseArgs } from \"util\";\nimport { aiCommand } from \"./commands/ai\";", "old_string": "old", "replace_all": false}"#;
        let fixture = ToolCallArguments::from_json(json_str);
        let normalized = fixture.normalize();

        match &normalized {
            ToolCallArguments::Parsed(value) => {
                assert_eq!(value["file_path"], "/home/kassie/projects/test.ts");
                assert_eq!(value["replace_all"], false);
            }
            ToolCallArguments::Unparsed(s) => {
                panic!("Should have parsed valid JSON, but got Unparsed: {}", s);
            }
        }
    }

    #[test]
    fn test_into_string_unparsed() {
        let fixture = ToolCallArguments::from_json(r#"{"param": "value"}"#);
        let actual = fixture.into_string();
        let expected = r#"{"param": "value"}"#;
        assert_eq!(actual, expected);
    }

    #[test]
    fn test_into_string_parsed() {
        let fixture = ToolCallArguments::Parsed(json!({"param": "value"}));
        let actual = fixture.into_string();
        let expected = r#"{"param":"value"}"#;
        assert_eq!(actual, expected);
    }
}