yui-cli 0.4.0

//! TOML schema for yui configuration.
//!
//! Loading flow:
//!   1. list `config.toml` + `config.*.toml` (alphabetical) + `config.local.toml` (last)
//!   2. for each file: Tera-render with `yui.*` + `env(…)` + accumulated `vars.*`
//!      from prior files → parse TOML → merge into accumulator (deep merge,
//!      arrays append).
//!   3. deserialize the final merged table into `Config`.
//!
//! Note: a file cannot reference its own `[vars]` keys from non-`[vars]`
//! sections (the file is rendered before its own vars are accumulated).
//! Use prior files in merge order if you need cross-section references.

use camino::{Utf8Path, Utf8PathBuf};
use serde::Deserialize;

use crate::vars::YuiVars;
use crate::{Error, Result, template};

#[derive(Debug, Deserialize, Default)]
pub struct Config {
    #[serde(default)]
    pub vars: toml::Table,

    #[serde(default)]
    pub link: LinkConfig,

    #[serde(default)]
    pub mount: MountConfig,

    #[serde(default)]
    pub absorb: AbsorbConfig,

    #[serde(default)]
    pub render: RenderConfig,

    #[serde(default)]
    pub backup: BackupConfig,

    #[serde(default)]
    pub ui: UiConfig,
}

#[derive(Debug, Deserialize, Default)]
pub struct UiConfig {
    #[serde(default)]
    pub icons: IconsMode,
}

#[derive(Debug, Deserialize, Default, Clone, Copy, PartialEq, Eq, clap::ValueEnum)]
#[serde(rename_all = "lowercase")]
pub enum IconsMode {
    /// `✓ ✗ → ─` — works on any terminal that renders basic Unicode (default).
    #[default]
    Unicode,
    /// Nerd Font glyphs (`  →`) — requires a Nerd-Font-patched terminal font.
    Nerd,
    /// `[+] [-] -> -` — pure ASCII, for CI logs / SSH-into-legacy-tty.
    Ascii,
}

#[derive(Debug, Deserialize, Default)]
pub struct LinkConfig {
    #[serde(default)]
    pub file_mode: FileLinkMode,
    #[serde(default)]
    pub dir_mode: DirLinkMode,
}

#[derive(Debug, Deserialize, Default, Clone, Copy, PartialEq, Eq)]
#[serde(rename_all = "lowercase")]
pub enum FileLinkMode {
    #[default]
    Auto,
    Symlink,
    Hardlink,
}

#[derive(Debug, Deserialize, Default, Clone, Copy, PartialEq, Eq)]
#[serde(rename_all = "lowercase")]
pub enum DirLinkMode {
    #[default]
    Auto,
    Symlink,
    Junction,
}

#[derive(Debug, Deserialize)]
pub struct MountConfig {
    #[serde(default)]
    pub default_strategy: MountStrategy,
    #[serde(default = "default_marker_filename")]
    pub marker_filename: String,
    #[serde(default)]
    pub entry: Vec<MountEntry>,
}

impl Default for MountConfig {
    fn default() -> Self {
        Self {
            default_strategy: MountStrategy::default(),
            marker_filename: default_marker_filename(),
            entry: Vec::new(),
        }
    }
}

fn default_marker_filename() -> String {
    ".yuilink".to_string()
}

#[derive(Debug, Deserialize, Default, Clone, Copy, PartialEq, Eq)]
#[serde(rename_all = "kebab-case")]
pub enum MountStrategy {
    #[default]
    Marker,
    PerFile,
}

#[derive(Debug, Deserialize)]
pub struct MountEntry {
    pub src: Utf8PathBuf,
    pub dst: String,
    #[serde(default)]
    pub when: Option<String>,
    #[serde(default)]
    pub strategy: Option<MountStrategy>,
}

#[derive(Debug, Deserialize)]
pub struct AbsorbConfig {
    #[serde(default = "default_true")]
    pub auto: bool,
    #[serde(default = "default_true")]
    pub require_clean_git: bool,
    #[serde(default)]
    pub on_anomaly: AnomalyAction,
}

impl Default for AbsorbConfig {
    fn default() -> Self {
        Self {
            auto: true,
            require_clean_git: true,
            on_anomaly: AnomalyAction::default(),
        }
    }
}

#[derive(Debug, Deserialize, Default, Clone, Copy, PartialEq, Eq)]
#[serde(rename_all = "lowercase")]
pub enum AnomalyAction {
    #[default]
    Ask,
    Skip,
    Force,
}

#[derive(Debug, Deserialize)]
pub struct RenderConfig {
    #[serde(default = "default_true")]
    pub manage_gitignore: bool,
    #[serde(default)]
    pub rule: Vec<RenderRule>,
}

impl Default for RenderConfig {
    fn default() -> Self {
        Self {
            manage_gitignore: true,
            rule: Vec::new(),
        }
    }
}

#[derive(Debug, Deserialize)]
pub struct RenderRule {
    pub r#match: String,
    #[serde(default)]
    pub when: Option<String>,
}

#[derive(Debug, Deserialize)]
pub struct BackupConfig {
    #[serde(default = "default_backup_dir")]
    pub dir: String,
    #[serde(default = "default_ts_format")]
    pub timestamp_format: String,
}

impl Default for BackupConfig {
    fn default() -> Self {
        Self {
            dir: default_backup_dir(),
            timestamp_format: default_ts_format(),
        }
    }
}

fn default_backup_dir() -> String {
    ".yui/backup".to_string()
}

fn default_ts_format() -> String {
    "%Y%m%d_%H%M%S%3f".to_string()
}

fn default_true() -> bool {
    true
}

/// Load + merge config files from `$DOTFILES`.
pub fn load(source: &Utf8Path, yui: &YuiVars) -> Result<Config> {
    let files = list_config_files(source)?;
    if files.is_empty() {
        return Err(Error::Config(format!(
            "no config.toml / config.*.toml found at {source}"
        )));
    }

    let mut engine = template::Engine::new();
    let mut merged = toml::Table::new();
    let mut vars_acc = toml::Table::new();

    for file in &files {
        let raw = std::fs::read_to_string(file)
            .map_err(|e| Error::Config(format!("read {file}: {e}")))?;
        let ctx = template::template_context(yui, &vars_acc);
        let rendered = engine.render(&raw, &ctx)?;
        let parsed: toml::Table =
            toml::from_str(&rendered).map_err(|e| Error::Config(format!("parse {file}: {e}")))?;

        if let Some(toml::Value::Table(file_vars)) = parsed.get("vars") {
            deep_merge_table(&mut vars_acc, file_vars.clone());
        }
        deep_merge_table(&mut merged, parsed);
    }

    let cfg: Config = toml::Value::Table(merged)
        .try_into()
        .map_err(|e| Error::Config(format!("schema: {e}")))?;
    Ok(cfg)
}

/// List config files in merge order:
///   `config.toml` (rank 0)
/// → `config.*.toml` alphabetically (rank 1, excluding `config.local.toml`)
/// → `config.local.toml` (rank 2, last/highest priority)
fn list_config_files(source: &Utf8Path) -> Result<Vec<Utf8PathBuf>> {
    let entries =
        std::fs::read_dir(source).map_err(|e| Error::Config(format!("read_dir {source}: {e}")))?;
    let mut files: Vec<Utf8PathBuf> = Vec::new();
    for entry in entries {
        let entry = entry.map_err(Error::Io)?;
        let name_os = entry.file_name();
        let Some(name) = name_os.to_str() else {
            continue;
        };
        let is_match = name == "config.toml"
            || (name.starts_with("config.") && name.ends_with(".toml") && name.len() > 12);
        if !is_match {
            continue;
        }
        let path = Utf8PathBuf::from_path_buf(entry.path())
            .map_err(|p| Error::Config(format!("non-UTF8 config path: {}", p.display())))?;
        files.push(path);
    }
    files.sort_by(|a, b| {
        let an = a.file_name().unwrap_or("");
        let bn = b.file_name().unwrap_or("");
        file_rank(an).cmp(&file_rank(bn)).then_with(|| an.cmp(bn))
    });
    Ok(files)
}

fn file_rank(name: &str) -> u8 {
    match name {
        "config.toml" => 0,
        "config.local.toml" => 2,
        _ => 1,
    }
}

/// Deep-merge `overlay` into `base`. Tables recurse; arrays append; scalars
/// overlay-wins.
fn deep_merge_table(base: &mut toml::Table, overlay: toml::Table) {
    for (k, v) in overlay {
        match (base.remove(&k), v) {
            (Some(toml::Value::Table(mut bt)), toml::Value::Table(ot)) => {
                deep_merge_table(&mut bt, ot);
                base.insert(k, toml::Value::Table(bt));
            }
            (Some(toml::Value::Array(mut ba)), toml::Value::Array(oa)) => {
                ba.extend(oa);
                base.insert(k, toml::Value::Array(ba));
            }
            (_, v) => {
                base.insert(k, v);
            }
        }
    }
}

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

    fn yui_vars(source: &Utf8Path) -> YuiVars {
        YuiVars {
            os: "linux".into(),
            arch: "x86_64".into(),
            host: "test".into(),
            user: "u".into(),
            source: source.to_string(),
        }
    }

    fn write(tmp: &TempDir, name: &str, body: &str) {
        std::fs::write(tmp.path().join(name), body).unwrap();
    }

    fn root(tmp: &TempDir) -> Utf8PathBuf {
        Utf8PathBuf::from_path_buf(tmp.path().to_path_buf()).unwrap()
    }

    #[test]
    fn loads_single_file() {
        let tmp = TempDir::new().unwrap();
        write(
            &tmp,
            "config.toml",
            r#"
[vars]
git_email = "a@example.com"

[[mount.entry]]
src = "home"
dst = "/home/u"
"#,
        );
        let r = root(&tmp);
        let cfg = load(&r, &yui_vars(&r)).unwrap();
        assert_eq!(
            cfg.vars.get("git_email").unwrap().as_str(),
            Some("a@example.com")
        );
        assert_eq!(cfg.mount.entry.len(), 1);
        assert_eq!(cfg.mount.entry[0].dst, "/home/u");
    }

    #[test]
    fn local_overrides_base() {
        let tmp = TempDir::new().unwrap();
        write(
            &tmp,
            "config.toml",
            r#"
[vars]
git_email = "a@example.com"
work_mode = false
"#,
        );
        write(
            &tmp,
            "config.local.toml",
            r#"
[vars]
git_email = "b@work.com"
"#,
        );
        let r = root(&tmp);
        let cfg = load(&r, &yui_vars(&r)).unwrap();
        assert_eq!(
            cfg.vars.get("git_email").unwrap().as_str(),
            Some("b@work.com")
        );
        // unchanged keys preserved
        assert_eq!(cfg.vars.get("work_mode").unwrap().as_bool(), Some(false));
    }

    #[test]
    fn alphabetical_middle_files_apply_after_base_before_local() {
        let tmp = TempDir::new().unwrap();
        write(
            &tmp,
            "config.toml",
            r#"[vars]
val = "base""#,
        );
        write(
            &tmp,
            "config.aaa.toml",
            r#"[vars]
val = "aaa""#,
        );
        write(
            &tmp,
            "config.zzz.toml",
            r#"[vars]
val = "zzz""#,
        );
        write(
            &tmp,
            "config.local.toml",
            r#"[vars]
val = "local""#,
        );
        let r = root(&tmp);
        let cfg = load(&r, &yui_vars(&r)).unwrap();
        assert_eq!(cfg.vars.get("val").unwrap().as_str(), Some("local"));
    }

    #[test]
    fn yui_vars_available_in_render() {
        let tmp = TempDir::new().unwrap();
        write(
            &tmp,
            "config.toml",
            r#"
[[mount.entry]]
src = "home"
dst = "/{{ yui.os }}/dst"
"#,
        );
        let r = root(&tmp);
        let cfg = load(&r, &yui_vars(&r)).unwrap();
        assert_eq!(cfg.mount.entry[0].dst, "/linux/dst");
    }

    #[test]
    fn mount_entries_append_across_files() {
        let tmp = TempDir::new().unwrap();
        write(
            &tmp,
            "config.toml",
            r#"
[[mount.entry]]
src = "home"
dst = "/h"
"#,
        );
        write(
            &tmp,
            "config.local.toml",
            r#"
[[mount.entry]]
src = "appdata"
dst = "/a"
"#,
        );
        let r = root(&tmp);
        let cfg = load(&r, &yui_vars(&r)).unwrap();
        assert_eq!(cfg.mount.entry.len(), 2);
    }

    #[test]
    fn missing_config_errors() {
        let tmp = TempDir::new().unwrap();
        let r = root(&tmp);
        let err = load(&r, &yui_vars(&r)).unwrap_err();
        assert!(matches!(err, Error::Config(_)));
    }

    #[test]
    fn defaults_apply_when_sections_absent() {
        let tmp = TempDir::new().unwrap();
        write(&tmp, "config.toml", "");
        let r = root(&tmp);
        let cfg = load(&r, &yui_vars(&r)).unwrap();
        assert!(cfg.absorb.auto);
        assert!(cfg.absorb.require_clean_git);
        assert!(cfg.render.manage_gitignore);
        assert_eq!(cfg.backup.dir, ".yui/backup");
        assert_eq!(cfg.mount.marker_filename, ".yuilink");
    }
}