rustbrain-core 0.2.0

//! Deterministic workspace bootstrap for mature repositories.
//!
//! Creates docs scaffolds, optional `.rustbrainignore`, README-derived goals,
//! and an AST module map — **without** inventing ADRs or calling cloud models.

use crate::error::{BrainError, Result};
use crate::ignore::{recommended_ignore_extras, write_rustbrainignore};

use serde::{Deserialize, Serialize};
use std::io::{self, BufRead, IsTerminal, Write};
use std::path::{Path, PathBuf};

/// How to handle interactive prompts.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum BootstrapMode {
    /// Prompt on a TTY; use defaults when stdin is not a terminal.
    Interactive,
    /// Never prompt; use options as given.
    NonInteractive,
}

/// Options for [`bootstrap_workspace`].
#[derive(Debug, Clone)]
pub struct BootstrapOptions {
    /// Interaction mode.
    pub mode: BootstrapMode,
    /// Write files (false = dry-run report only).
    pub write: bool,
    /// Overwrite generated files that already exist.
    pub force: bool,
    /// Create / update `.rustbrainignore`.
    pub setup_ignore: Option<bool>,
    /// Import root `.gitignore` into `.rustbrainignore`.
    pub import_gitignore: Option<bool>,
    /// Append recommended extra ignore patterns.
    pub ignore_extras: bool,
    /// Harvest README into docs/goals/from-readme.md.
    pub harvest_readme: bool,
    /// Generate AST module map under docs/implementation/.
    pub module_map: bool,
    /// Scaffold docs/ directory tree + templates.
    pub scaffold_docs: bool,
}

impl Default for BootstrapOptions {
    fn default() -> Self {
        Self {
            mode: BootstrapMode::Interactive,
            write: true,
            force: false,
            setup_ignore: None,
            import_gitignore: None,
            ignore_extras: true,
            harvest_readme: true,
            module_map: true,
            scaffold_docs: true,
        }
    }
}

/// One planned or performed action.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BootstrapAction {
    /// Short verb (create, skip, would_create).
    pub action: String,
    /// Relative path affected.
    pub path: String,
    /// Detail message.
    pub detail: String,
}

/// Result of bootstrap.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BootstrapReport {
    /// Workspace.
    pub workspace: PathBuf,
    /// Whether files were written.
    pub wrote: bool,
    /// Actions taken or planned.
    pub actions: Vec<BootstrapAction>,
}

const DOC_DIRS: &[&str] = &[
    "docs/goals",
    "docs/adr",
    "docs/concepts",
    "docs/edge_cases",
    "docs/implementation",
    "docs/experience",
];

/// Run deterministic bootstrap for `workspace`.
pub fn bootstrap_workspace(workspace: &Path, mut opts: BootstrapOptions) -> Result<BootstrapReport> {
    let workspace = if workspace.exists() {
        workspace.canonicalize()?
    } else {
        std::fs::create_dir_all(workspace)?;
        workspace.canonicalize()?
    };

    resolve_interactive(&workspace, &mut opts)?;

    let mut actions = Vec::new();
    let wrote = opts.write;

    if opts.scaffold_docs {
        scaffold_docs(&workspace, opts.write, opts.force, &mut actions)?;
    }

    if opts.setup_ignore.unwrap_or(false) {
        setup_ignore(
            &workspace,
            opts.write,
            opts.force,
            opts.import_gitignore.unwrap_or(false),
            opts.ignore_extras,
            &mut actions,
        )?;
    }

    if opts.harvest_readme {
        harvest_readme(&workspace, opts.write, opts.force, &mut actions)?;
    }

    if opts.module_map {
        #[cfg(feature = "ast")]
        generate_module_map(&workspace, opts.write, opts.force, &mut actions)?;
        #[cfg(not(feature = "ast"))]
        {
            actions.push(BootstrapAction {
                action: "skip".into(),
                path: "docs/implementation/module-map.generated.md".into(),
                detail: "ast feature disabled — module map not generated".into(),
            });
        }
    }

    // Ensure brain exists when writing
    if opts.write {
        let brain = workspace.join(".brain");
        if !brain.join("db.sqlite").exists() {
            std::fs::create_dir_all(&brain)?;
            let _ = crate::storage::Database::open(brain.join("db.sqlite"))?;
            actions.push(BootstrapAction {
                action: "create".into(),
                path: ".brain/db.sqlite".into(),
                detail: "initialized empty brain database".into(),
            });
            let marker = brain.join("workspace.json");
            if !marker.exists() {
                let meta = serde_json::json!({
                    "version": 1,
                    "workspace": workspace.to_string_lossy(),
                    "bootstrapped": true,
                });
                std::fs::write(&marker, serde_json::to_string_pretty(&meta)?)?;
            }
        }
    }

    actions.push(BootstrapAction {
        action: "next".into(),
        path: ".".into(),
        detail: if wrote {
            "run `rustbrain sync` then `rustbrain doctor`".into()
        } else {
            "re-run with --write to apply".into()
        },
    });

    Ok(BootstrapReport {
        workspace,
        wrote,
        actions,
    })
}

fn resolve_interactive(workspace: &Path, opts: &mut BootstrapOptions) -> Result<()> {
    if opts.mode != BootstrapMode::Interactive {
        // Non-interactive defaults
        if opts.setup_ignore.is_none() {
            opts.setup_ignore = Some(true);
        }
        if opts.import_gitignore.is_none() {
            opts.import_gitignore = Some(workspace.join(".gitignore").is_file());
        }
        return Ok(());
    }

    let tty = io::stdin().is_terminal() && io::stdout().is_terminal();
    if !tty {
        if opts.setup_ignore.is_none() {
            opts.setup_ignore = Some(true);
        }
        if opts.import_gitignore.is_none() {
            opts.import_gitignore = Some(workspace.join(".gitignore").is_file());
        }
        return Ok(());
    }

    println!("rustbrain bootstrap — {}", workspace.display());
    println!("Deterministic setup (no cloud AI). Press Enter to accept [defaults].\n");

    if opts.setup_ignore.is_none() {
        let has = workspace.join(".rustbrainignore").is_file();
        let def = if has { "n" } else { "Y" };
        let ans = prompt(
            &format!(
                "Create/update .rustbrainignore? [Y/n] (default {def})"
            ),
            def,
        )?;
        opts.setup_ignore = Some(ans_yes(&ans, !has));
    }

    if opts.setup_ignore == Some(true) && opts.import_gitignore.is_none() {
        let has_gi = workspace.join(".gitignore").is_file();
        if has_gi {
            let ans = prompt(
                "Import patterns from root .gitignore into .rustbrainignore? [Y/n]",
                "Y",
            )?;
            opts.import_gitignore = Some(ans_yes(&ans, true));
        } else {
            opts.import_gitignore = Some(false);
            println!("  (no .gitignore found — skipping import)");
        }
    }

    if opts.setup_ignore == Some(true) {
        let ans = prompt(
            "Append recommended extras (target/, data/, *.parquet, .env, …)? [Y/n]",
            "Y",
        )?;
        opts.ignore_extras = ans_yes(&ans, true);

        // Offer free-form extra lines
        let ans = prompt(
            "Add extra ignore patterns now? (comma-separated, or empty) []",
            "",
        )?;
        if !ans.trim().is_empty() {
            // Stash extras in a side channel via env-like temporary — use a file write later
            // We'll append them in setup_ignore by reading a thread-local... cleaner: store on opts
            // Extend BootstrapOptions - for simplicity append into recommended via env
            std::env::set_var("RUSTBRAIN_BOOTSTRAP_EXTRA_IGNORES", ans.trim());
        }
    }

    if opts.harvest_readme {
        // already true; allow disable
        if workspace.join("README.md").is_file() {
            let ans = prompt("Harvest README.md into docs/goals/from-readme.md? [Y/n]", "Y")?;
            opts.harvest_readme = ans_yes(&ans, true);
        }
    }

    #[cfg(feature = "ast")]
    {
        let ans = prompt(
            "Generate docs/implementation/module-map.generated.md from Rust AST? [Y/n]",
            "Y",
        )?;
        opts.module_map = ans_yes(&ans, true);
    }

    let ans = prompt("Scaffold docs/ tree + ADR/goal templates? [Y/n]", "Y")?;
    opts.scaffold_docs = ans_yes(&ans, true);

    if !opts.write {
        let ans = prompt("Write files to disk? [Y/n]", "Y")?;
        opts.write = ans_yes(&ans, true);
    }

    Ok(())
}

fn prompt(msg: &str, default: &str) -> Result<String> {
    print!("{msg} ");
    io::stdout().flush()?;
    let mut line = String::new();
    io::stdin().lock().read_line(&mut line)?;
    let t = line.trim();
    if t.is_empty() {
        Ok(default.to_string())
    } else {
        Ok(t.to_string())
    }
}

fn ans_yes(ans: &str, default_yes: bool) -> bool {
    match ans.trim().to_ascii_lowercase().as_str() {
        "y" | "yes" => true,
        "n" | "no" => false,
        "" => default_yes,
        _ => default_yes,
    }
}

fn scaffold_docs(
    workspace: &Path,
    write: bool,
    force: bool,
    actions: &mut Vec<BootstrapAction>,
) -> Result<()> {
    for d in DOC_DIRS {
        let path = workspace.join(d);
        if path.is_dir() {
            actions.push(BootstrapAction {
                action: "exists".into(),
                path: d.to_string(),
                detail: "directory already present".into(),
            });
        } else if write {
            std::fs::create_dir_all(&path)?;
            actions.push(BootstrapAction {
                action: "create".into(),
                path: d.to_string(),
                detail: "created directory".into(),
            });
        } else {
            actions.push(BootstrapAction {
                action: "would_create".into(),
                path: d.to_string(),
                detail: "directory".into(),
            });
        }
    }

    // ADR template
    let adr_tpl = workspace.join("docs/adr/TEMPLATE.md");
    write_if_allowed(
        &adr_tpl,
        "docs/adr/TEMPLATE.md",
        ADR_TEMPLATE,
        write,
        force,
        actions,
    )?;

    // Goals placeholder if empty
    let goals_readme = workspace.join("docs/goals/README.md");
    write_if_allowed(
        &goals_readme,
        "docs/goals/README.md",
        GOALS_DIR_README,
        write,
        force,
        actions,
    )?;

    // Checklist
    let checklist = workspace.join("docs/BOOTSTRAP_CHECKLIST.md");
    write_if_allowed(
        &checklist,
        "docs/BOOTSTRAP_CHECKLIST.md",
        BOOTSTRAP_CHECKLIST,
        write,
        force,
        actions,
    )?;

    Ok(())
}

fn setup_ignore(
    workspace: &Path,
    write: bool,
    force: bool,
    import_gitignore: bool,
    extras: bool,
    actions: &mut Vec<BootstrapAction>,
) -> Result<()> {
    let path = workspace.join(".rustbrainignore");
    let rel = ".rustbrainignore";
    if path.exists() && !force {
        actions.push(BootstrapAction {
            action: "skip".into(),
            path: rel.into(),
            detail: "already exists (use --force to overwrite)".into(),
        });
        return Ok(());
    }

    let mut extra_lines: Vec<String> = Vec::new();
    extra_lines.push("# rustbrain: import-gitignore".into());
    if !import_gitignore {
        // comment marker only for documentation; runtime only imports when present
        // If user declined import, remove the directive
        extra_lines.clear();
    }

    if extras {
        for l in recommended_ignore_extras() {
            extra_lines.push(l.to_string());
        }
    }

    if let Ok(more) = std::env::var("RUSTBRAIN_BOOTSTRAP_EXTRA_IGNORES") {
        for part in more.split(',') {
            let p = part.trim();
            if !p.is_empty() {
                extra_lines.push(p.to_string());
            }
        }
    }

    let extras_ref: Vec<&str> = extra_lines.iter().map(|s| s.as_str()).collect();

    if write {
        write_rustbrainignore(workspace, import_gitignore, &extras_ref)?;
        actions.push(BootstrapAction {
            action: "create".into(),
            path: rel.into(),
            detail: format!(
                "ignore file (import_gitignore={import_gitignore}, extras={extras})"
            ),
        });
    } else {
        actions.push(BootstrapAction {
            action: "would_create".into(),
            path: rel.into(),
            detail: format!(
                "ignore file (import_gitignore={import_gitignore}, extras={extras})"
            ),
        });
    }
    Ok(())
}

fn harvest_readme(
    workspace: &Path,
    write: bool,
    force: bool,
    actions: &mut Vec<BootstrapAction>,
) -> Result<()> {
    let readme = workspace.join("README.md");
    let out_rel = "docs/goals/from-readme.md";
    let out = workspace.join(out_rel);
    if !readme.is_file() {
        actions.push(BootstrapAction {
            action: "skip".into(),
            path: out_rel.into(),
            detail: "no README.md at workspace root".into(),
        });
        return Ok(());
    }

    let text = std::fs::read_to_string(&readme)?;
    let body = extract_readme_sections(&text);
    let title = first_h1(&text).unwrap_or_else(|| {
        workspace
            .file_name()
            .and_then(|n| n.to_str())
            .unwrap_or("Project")
            .to_string()
    });

    let content = format!(
        "---\n\
         tags: [goal, readme, generated]\n\
         node_type: goal\n\
         aliases: [from-readme, {title}]\n\
         generated: true\n\
         source: README.md\n\
         ---\n\
         # Goals harvested from README\n\n\
         > Generated by `rustbrain bootstrap`. Edit freely; re-run with `--force` to regenerate.\n\n\
         Project title: **{title}**\n\n\
         {body}\n"
    );

    write_if_allowed(&out, out_rel, &content, write, force, actions)?;
    Ok(())
}

fn extract_readme_sections(text: &str) -> String {
    // Pull sections whose headings look goal-related, plus first paragraphs.
    let mut out = String::new();
    let mut capture = true; // preamble
    let mut current = String::new();
    let mut current_title = String::from("Overview");

    let flush = |title: &str, body: &str, out: &mut String| {
        let body = body.trim();
        if body.is_empty() {
            return;
        }
        out.push_str(&format!("## {title}\n\n{body}\n\n"));
    };

    for line in text.lines() {
        if let Some(rest) = line.strip_prefix("# ") {
            // top title — skip as section
            let _ = rest;
            continue;
        }
        if let Some(rest) = line.strip_prefix("## ") {
            flush(&current_title, &current, &mut out);
            current_title = rest.trim().to_string();
            current.clear();
            let lower = current_title.to_ascii_lowercase();
            capture = lower.contains("goal")
                || lower.contains("why")
                || lower.contains("feature")
                || lower.contains("non-goal")
                || lower.contains("non goal")
                || lower.contains("about")
                || lower.contains("overview")
                || lower.contains("require")
                || lower.contains("architect");
            continue;
        }
        if capture {
            current.push_str(line);
            current.push('\n');
        }
    }
    flush(&current_title, &current, &mut out);

    if out.trim().is_empty() {
        // Fallback: first 40 non-empty lines
        let mut n = 0;
        out.push_str("## Overview\n\n");
        for line in text.lines() {
            if line.trim().is_empty() {
                continue;
            }
            if line.starts_with('#') {
                continue;
            }
            out.push_str(line);
            out.push('\n');
            n += 1;
            if n >= 40 {
                break;
            }
        }
    }
    out
}

fn first_h1(text: &str) -> Option<String> {
    for line in text.lines() {
        if let Some(rest) = line.strip_prefix("# ") {
            let t = rest.trim();
            if !t.is_empty() {
                return Some(t.to_string());
            }
        }
    }
    None
}

#[cfg(feature = "ast")]
fn generate_module_map(
    workspace: &Path,
    write: bool,
    force: bool,
    actions: &mut Vec<BootstrapAction>,
) -> Result<()> {
    use crate::ast::CodeAstParser;
    use crate::id::rel_path_from_workspace;

    let out_rel = "docs/implementation/module-map.generated.md";
    let out = workspace.join(out_rel);
    let mut parser = CodeAstParser::new_rust().map_err(|e| BrainError::Ast(e.to_string()))?;

    let crate_name = workspace
        .file_name()
        .and_then(|n| n.to_str())
        .unwrap_or("crate")
        .to_string();

    // Prefer package name from Cargo.toml
    let crate_name = read_package_name(workspace).unwrap_or(crate_name);

    let mut sections: Vec<(String, Vec<String>)> = Vec::new();
    walk_rs(workspace, &mut |path| {
        let rel = rel_path_from_workspace(workspace, path);
        let rel_str = rel.to_string_lossy().replace('\\', "/");
        if rel_str.starts_with("target/") {
            return;
        }
        let Ok(src) = std::fs::read_to_string(path) else {
            return;
        };
        let Ok(anchors) = parser.parse_symbols(&crate_name, &rel_str, &src) else {
            return;
        };
        if anchors.is_empty() {
            return;
        }
        let mut lines = Vec::new();
        for a in anchors {
            // Prefer public-looking / type-level items first in display
            lines.push(format!(
                "- `{}` — symbol:{}::{}::{} (`{}` L{}-{})",
                a.symbol_name,
                a.crate_name,
                a.module_path,
                a.symbol_name,
                a.file_path,
                a.start_line,
                a.end_line
            ));
        }
        sections.push((rel_str, lines));
    })?;

    sections.sort_by(|a, b| a.0.cmp(&b.0));

    let mut body = String::from(
        "---\n\
         tags: [implementation, generated, ast]\n\
         node_type: concept\n\
         aliases: [module-map, generated-module-map]\n\
         generated: true\n\
         ---\n\
         # Module map (generated)\n\n\
         > Generated by `rustbrain bootstrap` from Tree-Sitter. Do not hand-edit;\n\
         > re-run bootstrap with `--force` to refresh.\n\n",
    );

    if sections.is_empty() {
        body.push_str("_No Rust symbols found._\n");
    } else {
        for (file, lines) in &sections {
            body.push_str(&format!("## `{file}`\n\n"));
            for l in lines {
                body.push_str(l);
                body.push('\n');
            }
            body.push('\n');
        }
    }

    write_if_allowed(&out, out_rel, &body, write, force, actions)?;
    Ok(())
}

#[cfg(feature = "ast")]
fn walk_rs(dir: &Path, f: &mut dyn FnMut(&Path)) -> Result<()> {
    if !dir.is_dir() {
        return Ok(());
    }
    for entry in std::fs::read_dir(dir)? {
        let entry = entry?;
        let path = entry.path();
        if path.is_dir() {
            if let Some(name) = path.file_name().and_then(|n| n.to_str()) {
                if matches!(
                    name,
                    "target" | ".git" | ".brain" | "node_modules" | "vendor"
                ) || name.starts_with('.')
                {
                    continue;
                }
            }
            walk_rs(&path, f)?;
        } else if path.extension().and_then(|e| e.to_str()) == Some("rs") {
            f(&path);
        }
    }
    Ok(())
}

fn read_package_name(workspace: &Path) -> Option<String> {
    let text = std::fs::read_to_string(workspace.join("Cargo.toml")).ok()?;
    let mut in_package = false;
    for line in text.lines() {
        let t = line.trim();
        if t.starts_with('[') {
            in_package = t == "[package]";
            continue;
        }
        if in_package {
            if let Some(rest) = t.strip_prefix("name") {
                let rest = rest.trim().trim_start_matches('=').trim();
                let name = rest.trim_matches('"').trim_matches('\'').to_string();
                if !name.is_empty() {
                    return Some(name);
                }
            }
        }
    }
    None
}

fn write_if_allowed(
    abs: &Path,
    rel: &str,
    content: &str,
    write: bool,
    force: bool,
    actions: &mut Vec<BootstrapAction>,
) -> Result<()> {
    if abs.exists() && !force {
        // Allow overwrite of generated files marked generated: true
        if let Ok(existing) = std::fs::read_to_string(abs) {
            if existing.contains("generated: true") && write {
                std::fs::write(abs, content)?;
                actions.push(BootstrapAction {
                    action: "update".into(),
                    path: rel.into(),
                    detail: "regenerated (generated: true)".into(),
                });
                return Ok(());
            }
        }
        actions.push(BootstrapAction {
            action: "skip".into(),
            path: rel.into(),
            detail: "exists (use --force to overwrite)".into(),
        });
        return Ok(());
    }
    if write {
        if let Some(parent) = abs.parent() {
            std::fs::create_dir_all(parent)?;
        }
        std::fs::write(abs, content)?;
        actions.push(BootstrapAction {
            action: "create".into(),
            path: rel.into(),
            detail: "wrote file".into(),
        });
    } else {
        actions.push(BootstrapAction {
            action: "would_create".into(),
            path: rel.into(),
            detail: "file".into(),
        });
    }
    Ok(())
}

const ADR_TEMPLATE: &str = r#"---
tags: [adr]
node_type: adr
---
# ADR-XXXX: Title

## Status

Proposed

## Context

<!-- Why is this decision needed? -->

## Decision

<!-- What did we decide? -->

## Consequences

<!-- Trade-offs, follow-ups -->

<!-- After writing, rename to docs/adr/000N-slug.md and link from goals/concepts. -->
"#;

const GOALS_DIR_README: &str = r#"---
tags: [goal, index]
node_type: goal
---
# Goals index

Place project goals and non-goals here.

- `from-readme.md` — harvested by `rustbrain bootstrap` (when README exists)
- Add ADRs under `docs/adr/` for decisions that achieve these goals
"#;

const BOOTSTRAP_CHECKLIST: &str = r#"# Bootstrap checklist

Generated by `rustbrain bootstrap`. Tick items as you promote drafts into real knowledge.

- [ ] Review `docs/goals/from-readme.md` (edit for accuracy)
- [ ] Promote real architectural decisions into `docs/adr/0001-….md` (do **not** invent history)
- [ ] Skim `docs/implementation/module-map.generated.md` and link key symbols from concepts
- [ ] Add `edge_case` notes for known traps
- [ ] Run `rustbrain sync`
- [ ] Run `rustbrain doctor` and clear pending links
- [ ] Optional: `rustbrain note new --type concept --title "…" --note "…"` for atomic notes
"#;

/// Convenience used by CLI tests / agents: non-interactive write bootstrap.
pub fn bootstrap_noninteractive(workspace: &Path, write: bool, force: bool) -> Result<BootstrapReport> {
    bootstrap_workspace(
        workspace,
        BootstrapOptions {
            mode: BootstrapMode::NonInteractive,
            write,
            force,
            setup_ignore: Some(true),
            import_gitignore: Some(workspace.join(".gitignore").is_file()),
            ignore_extras: true,
            harvest_readme: true,
            module_map: true,
            scaffold_docs: true,
        },
    )
}

#[cfg(test)]
mod tests {
    use super::*;
    use tempfile::tempdir;

    #[test]
    fn bootstrap_writes_scaffold() {
        let dir = tempdir().unwrap();
        std::fs::write(
            dir.path().join("README.md"),
            "# Demo\n\n## Why\n\nFast local tools.\n\n## Features\n\n- A\n- B\n",
        )
        .unwrap();
        std::fs::write(dir.path().join(".gitignore"), "target/\n*.log\n").unwrap();
        std::fs::create_dir_all(dir.path().join("src")).unwrap();
        std::fs::write(dir.path().join("src/lib.rs"), "pub fn hello() {}\n").unwrap();
        std::fs::write(
            dir.path().join("Cargo.toml"),
            "[package]\nname = \"demo\"\nversion = \"0.1.0\"\nedition = \"2021\"\n",
        )
        .unwrap();

        let report = bootstrap_noninteractive(dir.path(), true, false).unwrap();
        assert!(report.wrote);
        assert!(dir.path().join("docs/goals").is_dir());
        assert!(dir.path().join("docs/adr/TEMPLATE.md").is_file());
        assert!(dir.path().join(".rustbrainignore").is_file());
        assert!(dir.path().join("docs/goals/from-readme.md").is_file());
        #[cfg(feature = "ast")]
        assert!(dir
            .path()
            .join("docs/implementation/module-map.generated.md")
            .is_file());
    }
}