specfold-core 0.2.2

//! Applying the fixes that need no judgement: exact replacements reported by rules, missing
//! frontmatter keys, and a chosen target for an ambiguous reference.

use super::plan::Plan;
use crate::check::finding::{Finding, Fix};
use crate::corpus::Corpus;
use crate::markdown::frontmatter::edit;
use crate::model::stamp;
use crate::workspace::vcs;
use anyhow::Result;
use serde_json::Value;
use std::collections::BTreeMap;

#[derive(Debug, Clone, Default)]
pub struct Pick {
    /// The id to use instead of an ambiguous reference.
    pub id: String,
    pub path: String,
    pub line: usize,
}

fn replace_on_line(text: &str, line: usize, from: &str, to: &str) -> Option<String> {
    let mut lines: Vec<String> = text.split_inclusive('\n').map(str::to_string).collect();
    let l = lines.get_mut(line.checked_sub(1)?)?;
    if !l.contains(from) {
        return None;
    }
    *l = l.replacen(from, to, 1);
    Some(lines.concat())
}

/// Fills id, title, status, created and updated where they are missing.
fn fill_frontmatter(c: &Corpus, idx: usize, text: &str) -> Result<String> {
    let d = &c.docs[idx];
    let initial = c.cfg.registry.get(&d.id.ty).map(|t| t.initial.clone()).unwrap_or_else(|| "draft".into());
    let created = vcs::first_commit_stamp(&c.cfg.root, &d.path)
        .and_then(|s| stamp::normalize_date(&s))
        .unwrap_or_else(stamp::today);
    let title = d.title.clone().unwrap_or_else(|| d.slug.replace('-', " "));
    edit::rewrite(text, |m| {
        m.entry("id").or_insert_with(|| Value::String(d.id.to_string()));
        m.entry("title").or_insert_with(|| Value::String(title));
        m.entry("status").or_insert_with(|| Value::String(initial));
        m.entry("created").or_insert_with(|| Value::String(created));
        m.entry("updated").or_insert_with(|| Value::String(stamp::today()));
        let ordered = edit::ordered(std::mem::take(m));
        *m = ordered;
    })
}

pub fn plan(c: &Corpus, findings: &[Finding], pick: Option<&Pick>) -> Result<(Plan, usize)> {
    let mut texts: BTreeMap<String, String> = BTreeMap::new();
    let mut applied = 0;
    let read = |texts: &mut BTreeMap<String, String>, p: &str| -> Option<String> {
        if let Some(t) = texts.get(p) {
            return Some(t.clone());
        }
        std::fs::read_to_string(c.cfg.root.join(p)).ok()
    };
    for f in findings {
        match (&f.fix, f.rule.as_str()) {
            (Some(Fix::Replace { path, line, from, to }), _) => {
                let Some(t) = read(&mut texts, path) else { continue };
                if let Some(n) = replace_on_line(&t, *line, from, to) {
                    texts.insert(path.clone(), n);
                    applied += 1;
                }
            }
            (_, "S1") if f.message.starts_with("missing") || f.message == "no frontmatter block" => {
                let Some(idx) = c.docs.iter().position(|d| d.path == f.path) else { continue };
                let Some(t) = read(&mut texts, &f.path) else { continue };
                texts.insert(f.path.clone(), fill_frontmatter(c, idx, &t)?);
                applied += 1;
            }
            (_, "L1") if !f.candidates.is_empty() => {
                let Some(p) = pick.filter(|p| p.path == f.path && p.line == f.line && f.candidates.contains(&p.id))
                else {
                    continue;
                };
                let Some(t) = read(&mut texts, &f.path) else { continue };
                let Some(target) = f.message.split("]]").next().and_then(|s| s.strip_prefix("[[")) else { continue };
                let target_base = target.split('#').next().unwrap_or(target);
                if let Some(n) = replace_on_line(&t, f.line, &format!("[[{target_base}"), &format!("[[{}", p.id)) {
                    texts.insert(f.path.clone(), n);
                    applied += 1;
                }
            }
            _ => {}
        }
    }
    let mut plan = Plan::default();
    for (path, content) in texts {
        plan.write(path, content, false);
    }
    Ok((plan, applied))
}