//! 宪法状态文件加载工具

use serde::{Deserialize, Serialize};
use std::fs;
use std::path::Path;

/// 宪法状态文件结构
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ConstitutionalState {
    pub version: String,
    #[serde(default)]
    pub timestamp: Option<String>,
    #[serde(default)]
    pub constitutional_hash: Option<String>,
    pub parameters: Vec<Parameter>,
    pub clauses: Vec<Clause>,
    #[serde(default)]
    pub predicates: serde_json::Value,
}

/// 宪法参数
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Parameter {
    pub name: String,
    #[serde(default)]
    pub value: serde_json::Value,
    pub rust_type: String,
    pub clause: String,
    #[serde(default)]
    pub description: Option<String>,
}

/// 宪法条款
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Clause {
    pub id: String,
    pub level: String,
    pub title: String,
    #[serde(default)]
    pub predicate_hash: Option<String>,
    #[serde(default)]
    pub depends_on: Vec<String>,
}

/// 加载宪法状态文件
pub fn load_constitutional_state<P: AsRef<Path>>(path: P) -> Result<ConstitutionalState, String> {
    let content = fs::read_to_string(path).map_err(|e| e.to_string())?;
    serde_json::from_str(&content).map_err(|e| e.to_string())
}

/// 查找宪法状态文件
pub fn find_constitutional_state_file<P: AsRef<Path>>(start_dir: P) -> Option<std::path::PathBuf> {
    let mut current = start_dir.as_ref().to_path_buf();

    loop {
        let state_file = current.join("constitutional_state.json");
        if state_file.exists() {
            return Some(state_file);
        }

        // 向上查找父目录
        if !current.pop() {
            break;
        }
    }

    None
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::io::Write;
    use tempfile::NamedTempFile;

    #[test]
    fn test_load_constitutional_state() {
        let json = r#"{
            "version": "1.0.0",
            "parameters": [
                {
                    "name": "CBPP_DT_MIN",
                    "value": 100,
                    "rust_type": "u64",
                    "clause": "CONS_FLUID_BLOCK"
                }
            ],
            "clauses": [
                {
                    "id": "CONS_FLUID_BLOCK",
                    "level": "eternal",
                    "title": "流动区块生产"
                }
            ]
        }"#;

        let mut temp_file = NamedTempFile::new().unwrap();
        temp_file.write_all(json.as_bytes()).unwrap();

        let state = load_constitutional_state(temp_file.path()).unwrap();
        assert_eq!(state.version, "1.0.0");
        assert_eq!(state.parameters.len(), 1);
        assert_eq!(state.clauses.len(), 1);
    }
}