todo-tree 1.1.0

//! JSON rendering.

use super::options::PrintOptions;
use super::utils::format_path;
use crate::core::ScanResult;
use serde::Serialize;
use std::collections::HashMap;
use std::io::{self, Write};

/// The top-level JSON document written by [`print_json`].
#[derive(Debug, Serialize)]
pub struct JsonOutput {
    /// Files with at least one TODO item, sorted by path.
    pub files: Vec<JsonFileEntry>,
    /// Aggregate counts for the scan.
    pub summary: JsonSummary,
}

/// A single file's TODO items in the JSON output.
#[derive(Debug, Serialize)]
pub struct JsonFileEntry {
    /// The file's display path.
    pub path: String,
    /// The TODO items found in the file.
    pub items: Vec<JsonTodoItem>,
}

/// A single TODO item in the JSON output.
#[derive(Debug, Serialize)]
pub struct JsonTodoItem {
    /// The tag that matched.
    pub tag: String,
    /// The comment text following the tag.
    pub message: String,
    /// 1-based line number.
    pub line: usize,
    /// 1-based column.
    pub column: usize,
    /// The optional author/assignee.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub author: Option<String>,
    /// The item's priority, formatted with `{:?}` (e.g. `"Critical"`).
    pub priority: String,
}

/// Aggregate counts in the JSON output.
#[derive(Debug, Serialize)]
pub struct JsonSummary {
    /// Total number of TODO items found across all files.
    pub total_count: usize,
    /// Number of files that contained at least one TODO item.
    pub files_with_todos: usize,
    /// Total number of files scanned.
    pub files_scanned: usize,
    /// Number of items found per tag.
    pub tag_counts: HashMap<String, usize>,
    /// How long the scan took, in milliseconds.
    pub duration_ms: u128,
}

/// Renders `result` as pretty-printed JSON.
pub fn print_json<W: Write>(
    writer: &mut W,
    result: &ScanResult,
    options: &PrintOptions,
) -> io::Result<()> {
    let json_result = JsonOutput::from_scan_result(result, options);
    let json_str = serde_json::to_string_pretty(&json_result).map_err(io::Error::other)?;
    writeln!(writer, "{}", json_str)?;
    Ok(())
}

impl JsonOutput {
    /// Builds the JSON document from a scan result and print options
    /// (options control whether paths are absolute, relative, or
    /// stripped to `options.base_path`).
    pub fn from_scan_result(result: &ScanResult, options: &PrintOptions) -> Self {
        let mut files: Vec<JsonFileEntry> = result
            .sorted_files()
            .iter()
            .map(|(path, items)| {
                let display_path = format_path(path, options);

                JsonFileEntry {
                    path: display_path,
                    items: items
                        .iter()
                        .map(|item| JsonTodoItem {
                            tag: item.tag.clone(),
                            message: item.message.clone(),
                            line: item.line,
                            column: item.column,
                            author: item.author.clone(),
                            priority: format!("{:?}", item.priority),
                        })
                        .collect(),
                }
            })
            .collect();

        files.sort_by(|a, b| a.path.cmp(&b.path));

        let summary = JsonSummary {
            total_count: result.summary.total_count,
            files_with_todos: result.summary.files_with_todos,
            files_scanned: result.summary.files_scanned,
            tag_counts: result.summary.tag_counts.clone(),
            duration_ms: result.summary.duration_ms,
        };

        Self { files, summary }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::core::{TodoItem, TodoPriority};
    use std::path::PathBuf;

    fn item(tag: &str, author: Option<&str>) -> TodoItem {
        TodoItem {
            tag: tag.to_string(),
            message: "msg".to_string(),
            line: 1,
            column: 1,
            line_content: None,
            author: author.map(str::to_string),
            priority: TodoPriority::from_tag(tag),
        }
    }

    #[test]
    fn from_scan_result_maps_items_and_summary() {
        let mut result = ScanResult::new(PathBuf::from("."));
        result.add_file(
            PathBuf::from("a.rs"),
            vec![item("TODO", Some("alice")), item("FIXME", None)],
        );

        let output = JsonOutput::from_scan_result(&result, &PrintOptions::default());

        assert_eq!(output.files.len(), 1);
        assert_eq!(output.files[0].items.len(), 2);
        assert_eq!(output.summary.total_count, 2);
        let with_author = output.files[0]
            .items
            .iter()
            .find(|i| i.tag == "TODO")
            .unwrap();
        assert_eq!(with_author.author.as_deref(), Some("alice"));
        assert_eq!(with_author.priority, "Medium");
    }

    #[test]
    fn from_scan_result_uses_full_paths_when_requested() {
        let mut result = ScanResult::new(PathBuf::from("."));
        result.add_file(PathBuf::from("a.rs"), vec![item("TODO", None)]);

        let opts = PrintOptions {
            full_paths: true,
            ..PrintOptions::default()
        };
        let output = JsonOutput::from_scan_result(&result, &opts);

        assert_eq!(
            output.files[0].path,
            PathBuf::from("a.rs").display().to_string()
        );
    }

    #[test]
    fn from_scan_result_strips_base_path_when_set() {
        let mut result = ScanResult::new(PathBuf::from("."));
        result.add_file(PathBuf::from("/repo/src/a.rs"), vec![item("TODO", None)]);

        let opts = PrintOptions {
            base_path: Some(PathBuf::from("/repo")),
            ..PrintOptions::default()
        };
        let output = JsonOutput::from_scan_result(&result, &opts);

        assert_eq!(output.files[0].path, "src/a.rs");
    }

    #[test]
    fn from_scan_result_falls_back_when_strip_prefix_fails() {
        let mut result = ScanResult::new(PathBuf::from("."));
        result.add_file(PathBuf::from("/repo/src/a.rs"), vec![item("TODO", None)]);

        let opts = PrintOptions {
            base_path: Some(PathBuf::from("/other")),
            ..PrintOptions::default()
        };
        let output = JsonOutput::from_scan_result(&result, &opts);

        assert_eq!(
            output.files[0].path,
            PathBuf::from("/repo/src/a.rs").display().to_string()
        );
    }

    #[test]
    fn print_json_writes_valid_pretty_json() {
        let mut result = ScanResult::new(PathBuf::from("."));
        result.add_file(PathBuf::from("a.rs"), vec![item("TODO", None)]);
        let mut buf = Vec::new();

        print_json(&mut buf, &result, &PrintOptions::default()).unwrap();
        let output = String::from_utf8(buf).unwrap();

        let parsed: serde_json::Value = serde_json::from_str(&output).unwrap();
        assert_eq!(parsed["summary"]["total_count"], 1);
        assert_eq!(parsed["files"][0]["path"], "a.rs");
    }
}