/**
 * cli-entrypoints.mjs — the bundled payload's CLI entrypoint generators.
 *
 * The bundled payload ships three CLI entrypoints (hermes / hermes-agent /
 * hermes-acp — mirrors [project.scripts] in pyproject.toml) staged into
 * agent-payload/bin/. They are fully self-relative, so a bundled artifact
 * works wherever it lands (and read-only, MSIX included):
 *
 *   win32 — distlib-MINTED launchers (scripts/desktop-cli/mint-launchers.py
 *   runs on the payload's own store python, whose architecture is by
 *   construction the target's). The minted exe is a plain PE + shebang +
 *   zip overlay of scripts/desktop-cli/launcher-wrapper.py. The shebang is
 *   `#!<launcher_dir>\..\tools\<entry>\python.exe` — the <launcher_dir>
 *   literal is resolved by the launcher at run time relative to its own
 *   directory, which is the relocatability mechanism (live-proved).
 *
 *   POSIX — $0-relative bash trampolines generated below. No PE is needed:
 *   a plain script exec'ing the store python is the entrypoint. They follow
 *   the $0 symlink chain so a link out on PATH (e.g. ~/.local/bin) resolves
 *   back into the install.
 *
 * Pure module: no side effects, importable from tests.
 */

import fs from 'node:fs'
import path from 'node:path'
import { fileURLToPath } from 'node:url'

const HERE = path.dirname(fileURLToPath(import.meta.url))

/** The three CLI entrypoints, mirroring [project.scripts] in pyproject.toml. */
export const CLI_LAUNCHER_SPECS = [
  { name: 'hermes', module: 'hermes_cli.main', func: 'main' },
  { name: 'hermes-agent', module: 'run_agent', func: 'main' },
  { name: 'hermes-acp', module: 'acp_adapter.entry', func: 'main' }
]

/**
 * Render scripts/desktop-cli/launcher-wrapper.py for one entry. The
 * relative paths are the payload's bin-relative layout facts, forward
 * slashes (same convention as the payload manifest — the wrapper splits
 * them itself, so one text works cross-platform).
 *
 * @param {{ module: string, func: string }} spec
 * @param {string} relRepo bin-relative repo dir, e.g. ../hermes-agent
 * @param {string} relSite bin-relative venv site-packages
 * @returns {string} the rendered wrapper source
 */
export function renderWinWrapper(spec, relRepo, relSite) {
  const template = fs.readFileSync(path.join(HERE, 'launcher-wrapper.py'), 'utf8')
  const substitutions = {
    __HERMES_ENTRY_MODULE__: spec.module,
    __HERMES_ENTRY_FUNC__: spec.func,
    __HERMES_REPO_REL__: relRepo,
    __HERMES_SITE_REL__: relSite
  }
  let text = template
  for (const [placeholder, value] of Object.entries(substitutions)) {
    if (value.includes('__')) {
      throw new Error(`bad substitution for ${placeholder}: ${JSON.stringify(value)}`)
    }
    text = text.replaceAll(placeholder, value)
  }
  for (const placeholder of Object.keys(substitutions)) {
    if (text.includes(placeholder)) {
      throw new Error(`launcher-wrapper.py has an unsubstituted ${placeholder}`)
    }
  }
  return text
}

/**
 * One POSIX trampoline. Rel paths are bin-relative with FORWARD slashes
 * (the same strings the win32 side bakes); the bash resolves them against
 * the trampoline's own directory.
 *
 * @param {{ name: string, module: string }} spec
 * @param {{ relPython: string, relSite: string, relRepo: string }} rels
 * @returns {string} executable bash text
 */
export function posixTrampolineScript(spec, rels) {
  const join = (rel) => ['"$BIN_DIR"', ...rel.split('/')].join('/')
  return `#!/usr/bin/env bash
# Generated by scripts/build-bundled-desktop.mjs — the bundled payload's
# POSIX CLI entrypoint (${spec.name}). Fully $0-relative: follows the
# symlink chain so a link out on PATH (~/.local/bin) resolves back into
# the install, then execs the store python with the payload's own import
# roots. Do not edit the generated copy — change the generator.
set -euo pipefail
self="$0"
while [ -L "$self" ]; do
  target="$(readlink "$self")"
  case "$target" in
    /*) self="$target" ;;
    *) self="$(dirname "$self")/$target" ;;
  esac
done
BIN_DIR="$(cd -- "$(dirname -- "$self")" && pwd)"

PYTHON=${join(rels.relPython)}
REPO=${join(rels.relRepo)}
SITE=${join(rels.relSite)}

[ -x "$PYTHON" ] || {
  echo "${spec.name}: bundled interpreter missing at $PYTHON — the Hermes install is damaged; reinstall from the website" >&2
  exit 2
}

# A sealed payload has no working editable install (its pointer names the
# BUILD machine), so its own import roots REPLACE any inherited PYTHONPATH.
# Repo first — its hermes_cli wins over anything stale in site-packages.
unset PYTHONPATH PYTHONHOME
export PYTHONPATH="$REPO:$SITE"
# Keep __pycache__ writes out of the (possibly read-only) payload.
if [ -z "\${PYTHONPYCACHEPREFIX:-}" ] && [ -n "\${HOME:-}" ]; then
  export PYTHONPYCACHEPREFIX="$HOME/.cache/hermes-pycache"
fi

exec "$PYTHON" -m ${spec.module} "$@"
`
}

/**
 * All three POSIX trampolines.
 * @param {{ relPython: string, relSite: string, relRepo: string }} rels
 * @returns {{ name: string, text: string }[]}
 */
export function posixTrampolineScripts(rels) {
  return CLI_LAUNCHER_SPECS.map((spec) => ({ name: spec.name, text: posixTrampolineScript(spec, rels) }))
}