use crate::error::{CliError, Result};
use serde_json::Value;
use std::{
    fs, io,
    path::{Path, PathBuf},
};

pub fn read_file_to_json(path: &PathBuf) -> Result<Value> {
    let content = fs::read_to_string(path).map_err(|e| io_error("读取文件", path, e))?;
    serde_json::from_str(&content).map_err(|e| {
        CliError::InvalidData(format!("解析 JSON '{}' 失败: {}", path.display(), e))
    })
}

pub fn write_json_to_file(path: &PathBuf, value: &Value) -> Result<()> {
    let content = serde_json::to_string_pretty(value).map_err(|e| {
        CliError::InvalidData(format!("序列化 JSON '{}' 失败: {}", path.display(), e))
    })?;
    fs::write(path, content).map_err(|e| io_error("写入文件", path, e))?;
    Ok(())
}

pub fn update_json_file<F>(path: &PathBuf, updater: F) -> Result<()>
where
    F: FnOnce(&mut Value) -> Result<()>,
{
    let mut json = read_file_to_json(path)?;
    updater(&mut json)?;
    write_json_to_file(path, &json)?;
    Ok(())
}

pub fn find_project_dir(path: &Option<String>) -> Result<PathBuf> {
    let path = path.as_deref().unwrap_or(".");
    Ok(PathBuf::from(path))
}

/// Wraps an [`io::Error`] with the operation name and path so error messages
/// stop being anonymous "os error 3" strings.
pub fn io_error(op: &str, path: &Path, err: io::Error) -> CliError {
    CliError::Io(io::Error::new(
        err.kind(),
        format!("{} '{}' 失败: {}", op, path.display(), err),
    ))
}