gwm-cli 1.4.0

use crate::config::{expand_placeholders, BranchType, WorktreeConfig};
use crate::error::{GwmError, Result};
use regex::Regex;
use std::sync::LazyLock;

/// Compile-time literal regexes lifted to module statics so each branch
/// validation / parse runs at ~50ns instead of recompiling the pattern
/// per call (issue #97). `LazyLock::new` defers the work until the
/// first access; `expect` is acceptable here because the input is a
/// hard-coded literal — a regex-compile failure would be a developer
/// bug caught by the test suite at first use, not a user-facing error
/// path the CLAUDE.md "no unwrap on user paths" rule targets.
///
/// `ISSUE_RE` pins the digits-only contract on issue numbers (no
/// scientific notation, no hex, no leading zeros stripped). `DESC_RE`
/// matches the post-`kebab` shape — leading alphanumeric, then a tail
/// of alphanumeric / dash. `BRANCH_RE` captures the three segments of
/// a gwm-style branch (`<type>/#<issue>-<desc>`) in one pass.
static ISSUE_RE: LazyLock<Regex> = LazyLock::new(|| Regex::new(r"^\d+$").expect("static ISSUE_RE compiles"));
static DESC_RE: LazyLock<Regex> =
  LazyLock::new(|| Regex::new(r"^[a-z0-9][a-z0-9-]*$").expect("static DESC_RE compiles"));
static BRANCH_RE: LazyLock<Regex> =
  LazyLock::new(|| Regex::new(r"^([a-z]+)/#(\d+)-([a-z0-9-]+)$").expect("static BRANCH_RE compiles"));

/// Built-in branch types — the fallback when `.gwm.toml` carries no
/// `[[branch_types]]` block. Kept as a `&[(&str, &str)]` const so the
/// static string table stays compile-time and zero-alloc; the runtime
/// view is materialised on demand via [`default_branch_types`].
pub const BRANCH_TYPES: &[(&str, &str)] = &[
  ("feat", "New feature implementation"),
  ("fix", "Bug fix"),
  ("hotfix", "Critical production bug fix"),
  ("docs", "Documentation changes"),
  ("test", "Test additions or modifications"),
  ("refactor", "Code restructuring"),
  ("chore", "Maintenance tasks"),
  ("perf", "Performance improvements"),
  ("ci", "CI/CD configuration"),
  ("build", "Build system changes"),
];

/// Runtime view of [`BRANCH_TYPES`] as a `Vec<BranchType>`. Used by
/// [`crate::config::Config::resolved_branch_types`] when no override
/// is configured, and by [`BranchSpec::validate`] / [`BranchSpec::new`]
/// to keep the legacy "no config = built-in defaults" contract.
pub fn default_branch_types() -> Vec<BranchType> {
  BRANCH_TYPES
    .iter()
    .map(|(name, desc)| BranchType {
      name: (*name).into(),
      description: (*desc).into(),
    })
    .collect()
}

#[derive(Debug, Clone)]
pub struct BranchSpec {
  pub type_: String,
  pub issue: String,
  pub desc: String,
}

impl BranchSpec {
  /// Construct a [`BranchSpec`] validated against the built-in branch
  /// types. Kept for callers (tests, internal helpers) that don't have
  /// a [`crate::config::Config`] in scope; production code paths
  /// (`gwm create`, TUI create) should use [`Self::new_with_types`]
  /// with the resolved list so per-repo overrides are honoured.
  pub fn new(type_: impl Into<String>, issue: impl Into<String>, desc: impl Into<String>) -> Result<Self> {
    Self::new_with_types(type_, issue, desc, &default_branch_types())
  }

  /// Construct a [`BranchSpec`] validated against the supplied list of
  /// allowed branch types — typically the output of
  /// [`crate::config::Config::resolved_branch_types`].
  pub fn new_with_types(
    type_: impl Into<String>,
    issue: impl Into<String>,
    desc: impl Into<String>,
    allowed: &[BranchType],
  ) -> Result<Self> {
    let s = Self {
      type_: type_.into(),
      issue: issue.into(),
      desc: kebab(&desc.into()),
    };
    s.validate_against(allowed)?;
    Ok(s)
  }

  /// Validate against the built-in branch types. Convenience wrapper
  /// around [`Self::validate_against`] for legacy call sites.
  pub fn validate(&self) -> Result<()> {
    self.validate_against(&default_branch_types())
  }

  /// Validate against the supplied list of allowed branch types. The
  /// error message produced when the type is rejected enumerates the
  /// allowed names so the TUI status bar / CLI stderr always shows the
  /// repo-local truth (built-in or `.gwm.toml`-driven).
  pub fn validate_against(&self, allowed: &[BranchType]) -> Result<()> {
    if !allowed.iter().any(|t| t.name == self.type_) {
      let names = allowed.iter().map(|t| t.name.as_str()).collect::<Vec<_>>().join(", ");
      return Err(GwmError::InvalidBranchType {
        got: self.type_.clone(),
        allowed: names,
      });
    }
    if !ISSUE_RE.is_match(&self.issue) {
      return Err(GwmError::InvalidIssue(self.issue.clone()));
    }
    if !DESC_RE.is_match(&self.desc) {
      return Err(GwmError::InvalidDescription(self.desc.clone()));
    }
    Ok(())
  }

  pub fn branch_name(&self, cfg: &WorktreeConfig, repo: &str) -> Result<String> {
    expand_placeholders(
      &cfg.branch_pattern,
      repo,
      Some(&self.type_),
      Some(&self.issue),
      Some(&self.desc),
      None,
    )
  }

  pub fn worktree_dirname(&self, cfg: &WorktreeConfig, repo: &str) -> Result<String> {
    expand_placeholders(
      &cfg.path_pattern,
      repo,
      Some(&self.type_),
      Some(&self.issue),
      Some(&self.desc),
      None,
    )
  }

  /// Resolve the absolute worktree path for this spec. `repo_path` is the
  /// main repo's working directory on disk — it feeds the `{repo_path}` /
  /// `{repo_parent}` placeholders so a `base` like `{repo_parent}/worktrees`
  /// can be expressed relative to the repo (matching, e.g., an editor's
  /// `../worktrees` convention).
  pub fn worktree_path(
    &self,
    cfg: &WorktreeConfig,
    repo: &str,
    repo_path: &std::path::Path,
  ) -> Result<std::path::PathBuf> {
    let base = expand_placeholders(
      &cfg.base,
      repo,
      Some(&self.type_),
      Some(&self.issue),
      Some(&self.desc),
      Some(repo_path),
    )?;
    let dir = self.worktree_dirname(cfg, repo)?;
    Ok(std::path::PathBuf::from(base).join(dir))
  }
}

/// Try to recover a BranchSpec from a free-form branch name like `feat/#123-my-desc`.
pub fn parse_branch(branch: &str) -> Option<BranchSpec> {
  let cap = BRANCH_RE.captures(branch)?;
  Some(BranchSpec {
    type_: cap.get(1)?.as_str().to_string(),
    issue: cap.get(2)?.as_str().to_string(),
    desc: cap.get(3)?.as_str().to_string(),
  })
}

pub fn kebab(input: &str) -> String {
  // Lowercase, then collapse every non-alphanumeric run into a single `-`.
  let lower = input.to_lowercase();
  let mut out = String::with_capacity(lower.len());
  let mut prev_dash = false;
  for c in lower.chars() {
    if c.is_ascii_alphanumeric() {
      out.push(c);
      prev_dash = false;
    } else if !prev_dash && !out.is_empty() {
      out.push('-');
      prev_dash = true;
    }
  }
  out.trim_matches('-').to_string()
}