#!/usr/bin/env bash
# ============================================================================
# venv-style activation for the Hermes dev environment (pm-managed tools).
#
#   source ./activate      (bash / zsh, repo root)
#   .\activate.ps1         (PowerShell)
#
# Emits the composed pm env (PATH + tool vars) into the CURRENT shell, with
# save/restore: `deactivate` undoes exactly what activation changed.
#
# `hermes` becomes a shell function for this checkout. It runs only while the
# shell is inside this worktree and refuses outside it, so a sibling worktree
# keeps its own command. A prompt prefix names the worktree.
#
# Sync through setup before selecting the environment. PM owns freshness;
# activation does not maintain a second dependency stamp. It trusts the
# recorded tool digest instead of re-hashing every entry. `hermes pm
# install` and `hermes update` keep that check.
# ============================================================================
_HERMES_REPO="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# Options: `--test-extras a,b` selects the test environment's runtime extras
# (default: [all]); `--` ends options.
# A bare `source ./activate` inherits the caller's positional parameters.
# Ignore unrelated words so scripts with their own arguments can source it.
_hermes_test_env="--test-environment"
_hermes_expect_extras=""
for _hermes_arg in "$@"; do
    if [ -n "$_hermes_expect_extras" ]; then
        _hermes_test_env="--test-environment=$_hermes_arg"
        _hermes_expect_extras=""
        continue
    fi
    case "$_hermes_arg" in
        --) break ;;
        --test-extras) _hermes_expect_extras=1 ;;
        --test-extras=*) _hermes_test_env="--test-environment=${_hermes_arg#--test-extras=}" ;;
        *) : ;;
    esac
done
if [ -n "$_hermes_expect_extras" ]; then
    printf '%s\n' 'activate: --test-extras needs a comma-separated list' >&2
    unset _hermes_arg _hermes_test_env _hermes_expect_extras
    return 2 2>/dev/null || exit 2
fi
# Setup runs in a child: failures must not exit or partially activate the
# caller's shell, and activation must not republish launchers or shell config.
if ! (
    unset PYTHONHOME PYTHONPATH VIRTUAL_ENV
    bash "$_HERMES_REPO/setup-hermes.sh" --runtime-only "$_hermes_test_env"
) >&2; then
    printf '%s\n' 'activate: setup failed; shell environment unchanged' >&2
    unset _hermes_arg _hermes_test_env _hermes_expect_extras
    return 1 2>/dev/null || exit 1
fi
unset _hermes_arg _hermes_test_env _hermes_expect_extras

# Guard against double-sourcing: venv activate precedent (re-activating is a
# no-op re-save; we keep it idempotent by deactivating first). Key on the
# function, not the sentinel: child shells inherit __HERMES_ACTIVATED from an
# activated parent but never the function, and there is nothing to undo there.
if [ "$(type -t deactivate 2>/dev/null)" = "function" ]; then
    deactivate
fi

# Bootstrap Python only emits the environment; it does not install anything.
_hermes_repo="$_HERMES_REPO"
_hermes_py=""
for _hermes_candidate in "$_hermes_repo/.venv/bin/python" "$_hermes_repo/.venv/Scripts/python.exe" \
                         "$_hermes_repo/venv/bin/python" "$_hermes_repo/venv/Scripts/python.exe"; do
    [ -x "$_hermes_candidate" ] && { _hermes_py="$_hermes_candidate"; break; }
done
if [ -z "$_hermes_py" ]; then
    for _hermes_store in "${HERMES_RUNTIME_DIR:-}" "$_hermes_repo/../tools" "${HERMES_HOME:-$HOME/.hermes}/tools"; do
        [ -n "$_hermes_store" ] || continue
        for _hermes_candidate in "$_hermes_store"/python-*/bin/python3 "$_hermes_store"/python-*/python.exe "$_hermes_store"/python-*/bin/python "$_hermes_store"/python-*/bin/python.exe; do
            [ -x "$_hermes_candidate" ] && { _hermes_py="$_hermes_candidate"; break; }
        done
        [ -n "$_hermes_py" ] && break
    done
fi
if [ -z "$_hermes_py" ]; then
    echo "activate: no bootstrap Python found; run setup-hermes.sh" >&2
    return 1 2>/dev/null || exit 1
fi

# --- emit export lines from `pm env` ---
_hermes_json="$(PYTHONHOME= PYTHONPATH="$_hermes_repo" "$_hermes_py" -m pm.environments)"
if [ -z "$_hermes_json" ] || [ "${_hermes_json#*{}" = "$_hermes_json" ]; then
    echo "activate: could not read pm env (run ./setup-hermes.sh first)" >&2
    unset _hermes_repo _hermes_os _hermes_arch _hermes_target _hermes_store _hermes_py _hermes_json
    return 1 2>/dev/null || exit 1
fi

_hermes_keys="$(printf '%s' "$_hermes_json" | "$_hermes_py" -c 'import json,sys; print(" ".join(json.load(sys.stdin)))' \
    | tr ' ' '\n' | grep -E '^[A-Za-z_][A-Za-z0-9_]*$' | tr '\n' ' ')"
[ -n "$_hermes_keys" ] || _hermes_keys="PATH"

# --- snapshot what we are about to change (deactivate restores this) ---
# __HERMES_ACTIVATED is part of the composed env below (it carries the
# installed-state path this environment was built from), so it is snapshotted
# and exported with every other key — no separate assignment here.
__HERMES_SAVED_PATH="$PATH"
for _hermes_k in $_hermes_keys; do
    eval "__HERMES_SAVED_$_hermes_k=\"\${$_hermes_k+set}\""
    eval "__HERMES_PRIOR_$_hermes_k=\${$_hermes_k-__HERMES_UNSET__}"
done

# Resolved before the export below replaces PATH.
_hermes_cygpath="$(command -v cygpath 2>/dev/null || :)"

eval "$(printf '%s' "$_hermes_json" | "$_hermes_py" -c '
import json, sys, shlex, re
for k, v in json.load(sys.stdin).items():
    # Windows carries names like ProgramFiles(ARM) that are not valid
    # bash identifiers — skip them (they pass through untouched).
    if not re.fullmatch(r"[A-Za-z_][A-Za-z0-9_]*", k):
        continue
    print("export %s=%s" % (k, shlex.quote(str(v))))')"

# The MSYS/Cygwin runtime hands a native Windows Python these variables in
# Windows form (`C:\a;C:\b`) and converts them back only for its own children.
# Exported verbatim, bash splits PATH on ':' and finds no commands.
if [ -n "$_hermes_cygpath" ]; then
    PATH="$("$_hermes_cygpath" -u -p "$PATH")"
    for _hermes_k in HOME TMPDIR TMP TEMP; do
        if [ -n "${!_hermes_k-}" ]; then
            printf -v "$_hermes_k" '%s' "$("$_hermes_cygpath" -u "${!_hermes_k}")"
        fi
    done
fi

# This checkout, not whichever `hermes` PATH finds. A function beats PATH, an
# alias, and a hashed command, including the MSIX execution alias.
__HERMES_WORKTREE="$_hermes_repo"
# The branch names the worktree. A checkout cannot share a branch with another.
__HERMES_WORKTREE_NAME="$(git -C "$_hermes_repo" rev-parse --abbrev-ref HEAD 2>/dev/null || :)"
if [ -z "$__HERMES_WORKTREE_NAME" ] || [ "$__HERMES_WORKTREE_NAME" = HEAD ]; then
    __HERMES_WORKTREE_NAME="$(basename "$_hermes_repo")"
fi
__HERMES_SAVED_PS1="${PS1-__HERMES_UNSET__}"
__HERMES_SAVED_PROMPT_COMMAND="${PROMPT_COMMAND-__HERMES_UNSET__}"

_hermes_worktree_here() {
    _hermes_top="$(git rev-parse --show-toplevel 2>/dev/null)" || return 1
    [ "$(cd "$_hermes_top" && pwd -P)" = "$(cd "$__HERMES_WORKTREE" && pwd -P)" ]
}

hermes() {
    _hermes_worktree_here || {
        printf '%s\n' "hermes: $(pwd) is outside $__HERMES_WORKTREE; refusing (the installed command is hidden while this checkout is active)" >&2
        return 1
    }
    (
        cd "$__HERMES_WORKTREE" || exit 1
        if [ -n "${PYTHON-}" ]; then
            exec "$PYTHON" hermes "$@"
        elif [ -x .venv/Scripts/python.exe ]; then
            exec .venv/Scripts/python.exe hermes "$@"
        elif [ -x .venv/bin/python ]; then
            exec .venv/bin/python hermes "$@"
        elif [ -x venv/Scripts/python.exe ]; then
            exec venv/Scripts/python.exe hermes "$@"
        elif [ -x venv/bin/python ]; then
            exec venv/bin/python hermes "$@"
        else
            exec python hermes "$@"
        fi
    )
}

_hermes_prompt() {
    if [ "$__HERMES_SAVED_PS1" = "__HERMES_UNSET__" ]; then
        _hermes_base_ps1=""
    else
        _hermes_base_ps1="$__HERMES_SAVED_PS1"
    fi
    if _hermes_worktree_here; then
        PS1="($__HERMES_WORKTREE_NAME) $_hermes_base_ps1"
    else
        PS1="$_hermes_base_ps1"
    fi
}

if [ -n "${PROMPT_COMMAND-}" ]; then
    PROMPT_COMMAND="_hermes_prompt; ${PROMPT_COMMAND}"
else
    PROMPT_COMMAND=_hermes_prompt
fi
_hermes_prompt

deactivate() {
    export PATH="$__HERMES_SAVED_PATH"
    for _hermes_k in $__HERMES_KEY_LIST; do
        eval "_hermes_was=\"\$__HERMES_SAVED_$_hermes_k\""
        eval "_hermes_old=\"\$__HERMES_PRIOR_$_hermes_k\""
        if [ "$_hermes_was" != "set" ]; then
            unset "$_hermes_k"
        else
            export "$_hermes_k=$_hermes_old"
        fi
        unset "__HERMES_SAVED_$_hermes_k" "__HERMES_PRIOR_$_hermes_k"
    done
    if [ "$__HERMES_SAVED_PS1" = "__HERMES_UNSET__" ]; then
        unset PS1
    else
        PS1="$__HERMES_SAVED_PS1"
    fi
    if [ "$__HERMES_SAVED_PROMPT_COMMAND" = "__HERMES_UNSET__" ]; then
        unset PROMPT_COMMAND
    else
        PROMPT_COMMAND="$__HERMES_SAVED_PROMPT_COMMAND"
    fi
    unset __HERMES_SAVED_PATH __HERMES_KEY_LIST __HERMES_ACTIVATED \
          __HERMES_WORKTREE __HERMES_WORKTREE_NAME \
          __HERMES_SAVED_PS1 __HERMES_SAVED_PROMPT_COMMAND
    unset -f deactivate hermes _hermes_worktree_here _hermes_prompt
    unset _hermes_k _hermes_was _hermes_old _hermes_top
}

# remember the key list for deactivate (kept out of the loop vars above)
__HERMES_KEY_LIST="$_hermes_keys"

unset _hermes_repo _hermes_os _hermes_arch _hermes_target _hermes_store \
      _hermes_py _hermes_json _hermes_keys _hermes_k _hermes_entry _hermes_venvpy \
      _hermes_winarch _hermes_top _hermes_cygpath