#!/usr/bin/env bash
#
# Bun-compatibility fixups applied to installed dependencies. Runs AFTER `npm ci`
# (it edits node_modules) and BEFORE `bun build --compile`.
#
set -euo pipefail
ROOT="$(cd "$(dirname "$0")/.." && pwd)"
cd "$ROOT/httptoolkit-server"

# TypeScript's UMD emit wraps the module body in a factory that takes `require`
# as a *parameter*:
#
#   })(function (require, exports) {
#       var bplist_creator_1 = __importDefault(require("bplist-creator"));
#
# That parameter shadows the module-scope `require`, so bun's bundler can't
# statically link the call and leaves it as a runtime require. In a --compile'd
# binary there is no node_modules to fall back on, so the import fails at startup
# ("Cannot find package 'bplist-creator'"). Note that merely forcing the package
# into the bundle does NOT help: bun's runtime require only resolves call sites
# it linked at build time.
#
# Renaming the parameter un-shadows `require`, so the calls bind to the
# module-scope require that bun does link. The CJS branch still passes the real
# require in as the (now unused) first argument, so behaviour is unchanged.
deshadow_umd_require() {
    local dir="$1" found=0 already=0
    for file in "$dir"/*.js; do
        [ -e "$file" ] || continue
        if grep -q '})(function (require, exports) {' "$file"; then
            sed -i 's/})(function (require, exports) {/})(function (__umdRequire, exports) {/' "$file"
            found=$((found + 1))
        elif grep -q '__umdRequire' "$file"; then
            already=$((already + 1))
        fi
    done
    echo "  - $dir: patched $found, already patched $already"
    # Idempotent: re-running over an existing tree is fine. Only a tree with
    # neither form means the dependency changed shape under us.
    [ $((found + already)) -gt 0 ] \
        || { echo "!! no UMD wrappers found in $dir (dependency changed?)"; exit 1; }
}

echo "==> [node_modules] de-shadowing UMD require() calls for bun"
# Reached via @httptoolkit/browser-launcher -> simple-plist (darwin browser
# detection). Bun bundles every platform branch regardless of target, so this
# has to resolve even in a Linux build.
deshadow_umd_require node_modules/simple-plist/dist

# Native .node addons only get embedded into the compiled binary if bun can
# resolve the require statically. node-datachannel (via mockrtc) instead builds a
# require with module.createRequire():
#
#   const require$1 = module$1.createRequire(pathToFileURL(__filename).href);
#   const nodeDataChannel = require$1('../build/Release/node_datachannel.node');
#
# bun can't see through that, so the addon is left out and the binary resolves it
# relative to the *build-time* __filename at runtime - working on the build
# machine while failing everywhere else with "Cannot find module
# '../build/Release/node_datachannel.node'". Using a plain literal require makes
# bun embed the addon as an asset instead.
replace_literal() {
    local file="$1" from="$2" to="$3"
    [ -f "$file" ] || { echo "!! expected $file to exist (dependency changed?)"; exit 1; }
    if ! grep -qF "$from" "$file"; then
        # Idempotent: already-applied is fine, a missing target is not.
        if grep -qF "$to" "$file"; then
            echo "  - $file: already patched"
            return 0
        fi
        echo "!! pattern not found in $file: $from"; exit 1
    fi
    python3 - "$file" "$from" "$to" <<'PY'
import sys
path, old, new = sys.argv[1], sys.argv[2], sys.argv[3]
with open(path) as f: content = f.read()
with open(path, 'w') as f: f.write(content.replace(old, new))
PY
    echo "  - $file: $from -> $to"
}

echo "==> [node_modules] making native addon requires statically resolvable"
replace_literal node_modules/node-datachannel/lib/index.cjs \
    "require\$1('../build/Release/node_datachannel.node')" \
    "require('../build/Release/node_datachannel.node')"

# bun ships its own built-in `ws` shim and resolves the bare specifier "ws" to it,
# shadowing the real npm package. That shim has no createWebSocketStream (and no
# Receiver): it throws "Not supported yet in Bun". mockttp's admin server calls
# Ws.createWebSocketStream() for every admin client connection, so the server
# process died the moment the UI opened a session - after the UI had already
# loaded and looked fine.
#
# Requiring a subpath instead of the bare name escapes bun's shim and gets the
# real ws@8, which implements all of this. ws' exports map doesn't publish
# ./index.js, so add it before pointing anything at it.
redirect_ws_to_real_package() {
    local dir="$1" count=0
    # Publish the subpath we're about to require:
    if [ "$(jq -r '.exports["./index.js"] // "none"' node_modules/ws/package.json)" = "none" ]; then
        jq '.exports["./index.js"] = "./index.js"' node_modules/ws/package.json > node_modules/ws/package.json.tmp
        mv node_modules/ws/package.json.tmp node_modules/ws/package.json
        echo "  - ws/package.json: exposed ./index.js subpath"
    else
        echo "  - ws/package.json: subpath already exposed"
    fi

    while IFS= read -r file; do
        sed -i 's|require("ws")|require("ws/index.js")|g' "$file"
        echo "  - ${file#node_modules/}: -> ws/index.js"
        count=$((count + 1))
    done < <(grep -rl 'require("ws")' "$dir" --include=*.js 2>/dev/null || true)

    local already
    already=$(grep -rl 'require("ws/index.js")' "$dir" --include=*.js 2>/dev/null | wc -l)
    [ "$already" -gt 0 ] \
        || { echo "!! no bare ws requires found in $dir (dependency changed?)"; exit 1; }
}

echo "==> [node_modules] redirecting ws requires past bun's built-in shim"
redirect_ws_to_real_package node_modules/mockttp/dist

echo "==> patch-node-modules.sh complete."