repos:
  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v5.0.0
    hooks:
      - id: trailing-whitespace
        # These hooks don't read .gitattributes — they munge binaries
        # byte-for-byte. Exclude every format we actually ship as
        # binary so a commit with a PNG / .bin / font doesn't silently
        # corrupt it. Keeps text-hygiene checks on everything else.
        exclude: '\.(bin|png|jpe?g|gif|webp|ico|pdf|zip|gz|tar|woff2?|ttf|otf|eot)$'
      - id: end-of-file-fixer
        exclude: '\.(bin|png|jpe?g|gif|webp|ico|pdf|zip|gz|tar|woff2?|ttf|otf|eot)$'
      - id: check-yaml
      - id: check-json
      - id: check-merge-conflict
      - id: detect-private-key
      - id: check-added-large-files
        # Raised in steps as our raster resolution evolved:
        #   1 MB → 4 MB (0.05° land mask, 3.2 MB)
        #   4 MB → 15 MB (0.025° land mask, 12.4 MB — Bosphorus,
        #           Hjeltefjorden, narrow Norwegian fjords visible)
        # Natural Earth 10 m at 0.025° is the realistic top end before
        # we'd need a CDN. Going to 0.005° (Bosphorus-precise) would
        # cost ~200 MB and definitely belongs on a CDN.
        args: ['--maxkb=15000']

  - repo: https://github.com/astral-sh/ruff-pre-commit
    rev: v0.9.0
    hooks:
      - id: ruff
        args: [--fix]
        files: ^backend/src/scripts/.*\.py$

  - repo: local
    hooks:
      - id: prettier-frontend
        name: Prettier (frontend)
        language: node
        entry: npx --prefix frontend prettier --write
        files: ^frontend/src/.*\.(ts|tsx|css)$
        pass_filenames: true

      # ------------------------------------------------------------------
      # Correctness hooks.
      #
      # Before these, the only thing guarding a commit was Prettier — so
      # formatting was enforced and whether the code compiled was not. A
      # type error could be committed, pushed and merged, and the first
      # thing to notice would be a deploy-time `tsc` on the maintainer's
      # machine, long after the context was gone.
      #
      # `pass_filenames: false` and a whole-project run are deliberate:
      # both tsc and eslint resolve their config and module graph from the
      # project root, and handing them a list of individual staged files
      # makes them either miss cross-file type errors or fail to resolve
      # config at all. The `files:` pattern is what keeps the cost down —
      # it decides WHETHER the hook runs, not what it looks at. A commit
      # touching only backend/ never pays for the frontend checks.
      #
      # Measured cost on this machine (2026-08-30), so the trade-off is a
      # number rather than a feeling:
      #
      #   backend  — tsc 14 s, eslint  9 s
      #   frontend — tsc 27 s, eslint 16 s
      #
      # A commit touching one tree costs ~23 s (backend) or ~43 s
      # (frontend). If that becomes too slow to live with, drop the eslint
      # hooks first — CI runs both, and lint findings are cheaper to fix
      # late than type errors are.
      # ------------------------------------------------------------------
      - id: tsc-backend
        name: TypeScript (backend)
        language: system
        entry: bash -c 'cd backend && npx tsc --noEmit'
        files: ^backend/.*\.ts$
        pass_filenames: false

      - id: tsc-frontend
        name: TypeScript (frontend)
        language: system
        entry: bash -c 'cd frontend && npx tsc --noEmit'
        files: ^frontend/.*\.(ts|tsx)$
        pass_filenames: false

      - id: eslint-backend
        name: ESLint (backend)
        language: system
        entry: bash -c 'cd backend && npm run lint'
        files: ^backend/.*\.ts$
        pass_filenames: false

      # Runs with --max-warnings 0 (see frontend/package.json), so a new
      # warning blocks the commit instead of quietly accumulating.
      - id: eslint-frontend
        name: ESLint (frontend)
        language: system
        entry: bash -c 'cd frontend && npm run lint'
        files: ^frontend/.*\.(ts|tsx)$
        pass_filenames: false

# Deliberately NOT pre-commit hooks:
#
#   * The test suites. Vitest alone is ~37 s and the Jest suite needs a
#     live Postgres with migrations applied and catalogues seeded — a
#     commit hook that fails because a database container is not running
#     is a hook people disable within a week. CI runs both instead.
#   * Prettier over the whole frontend. ~95 files under frontend/src have
#     never been formatted, so a repo-wide `--check` would block every
#     commit for reasons unrelated to the change being made. The hook
#     above formats the staged files only.