//! Projects (spec §23.1): any kind of work a group of agents shares. A
//! project has a name, a description, and optionally a folder and a link;
//! Spectra records where the folder is and reads nothing inside it. The
//! owner links projects (`project.linked`: one depends on another), which
//! is what `to: "downstream"` follows.

use crate::event::Event;
use anyhow::{Context, Result};
use serde_json::Value as Json;
use sqlx::SqliteConnection;
use std::path::Path;

/// Kinds of event the owner signs about projects.
pub const KINDS: &[&str] = &["project.added", "project.linked", "project.unlinked"];

/// A project's name from a folder: its name, lower-cased, made valid.
pub fn default_name(path: &Path) -> Result<String> {
    let base = path.canonicalize()?.file_name().and_then(|n| n.to_str()).map(str::to_lowercase).context("the path has no name")?;
    Ok(base.chars().map(|c| if c.is_ascii_alphanumeric() || c == '-' { c } else { '-' }).collect())
}

/// Apply a project event to the tables.
pub async fn project(conn: &mut SqliteConnection, e: &Event) -> sqlx::Result<()> {
    let p = e.json();
    let s = |k: &str| p.get(k).and_then(Json::as_str).map(String::from);
    match e.kind.as_str() {
        "project.added" => {
            let Some(name) = s("name") else { return Ok(()) };
            sqlx::query("INSERT OR REPLACE INTO projects (name, path, description, url, seq) VALUES (?, ?, ?, ?, ?)")
                .bind(&name)
                .bind(s("path").filter(|p| !p.is_empty()))
                .bind(s("description").unwrap_or_default())
                .bind(s("url"))
                .bind(e.seq as i64)
                .execute(&mut *conn)
                .await?;
        }
        "project.linked" | "project.unlinked" => {
            let (Some(project), Some(on)) = (s("project"), s("depends_on")) else { return Ok(()) };
            let sql = if e.kind == "project.linked" {
                "INSERT OR IGNORE INTO project_relations (project, depends_on) VALUES (?, ?)"
            } else {
                "DELETE FROM project_relations WHERE project = ? AND depends_on = ?"
            };
            sqlx::query(sql).bind(project).bind(on).execute(&mut *conn).await?;
        }
        _ => {}
    }
    Ok(())
}