#!/usr/bin/env bash
# test_build_hub_tree_gate.sh — build-hub.sh refuses a stale or dirty tree (R-1021).
#
# Builds a tiny scratch repo (a bare "origin" + a clone holding the hub's directory shape), copies build-hub.sh next
# to it (so its workspace/ is scratch too) and runs it with FELHOM_HUB_REPO_DIR pointing at the clone and a STUB
# `docker` first on PATH: the real Docker is never called, nothing is built or pushed. Each case asserts the exit code
# AND a line of output:
#   dirty (an untracked file)          -> refused, "not clean"
#   dirty (a modified tracked file)    -> refused, "not clean"
#   behind origin, the pull blocked    -> refused (local commit diverged: "pull --ff-only failed")
#   ahead of origin (unpushed commit)  -> refused, "is not origin/main"
#   behind origin, the pull clean      -> passes, and the Commit line names the NEW head (read after the pull)
#   clean, at origin/main              -> passes, the stub docker reached
# Run: bash scripts/test_build_hub_tree_gate.sh   (exit 0 all cases right · 1 a case wrong)
set -uo pipefail
HERE="$(cd "$(dirname "$0")" && pwd)"
WS="$(mktemp -d)"
trap 'rm -rf "${WS:?}"' EXIT
fails=0

mkdir -p "$WS/bin" "$WS/build"
printf '#!/bin/sh\necho "STUB docker $*"\n' > "$WS/bin/docker"; chmod +x "$WS/bin/docker"
cp "$HERE/build-hub.sh" "$WS/build/build.sh"

fresh() {
    rm -rf "${WS:?}/origin.git" "${WS:?}/clone" "${WS:?}/other" "${WS:?}/build/workspace"
    git init -q --bare -b main "$WS/origin.git"
    git clone -q "$WS/origin.git" "$WS/clone" 2>/dev/null
    (cd "$WS/clone" && mkdir -p hub/cmd/hub hub/internal/api hub/internal/store hub/internal/web \
        && printf 'module x\n\ngo 1.22\n' > hub/go.mod && echo a > hub/cmd/hub/a.txt \
        && git add -A && git -c user.name=t -c user.email=t@t commit -q -m init && git push -q origin main)
    git clone -q "$WS/origin.git" "$WS/other" 2>/dev/null
}
upstream_commit() {  # a new commit on origin, made from another clone
    (cd "$WS/other" && git pull -q && echo "$1" > "hub/cmd/hub/$1.txt" && git add -A \
        && git -c user.name=t -c user.email=t@t commit -q -m "$1" && git push -q origin main)
}
run() {  # name, expected rc, required output fragment
    local out rc
    out=$(cd "$WS/build" && PATH="$WS/bin:$PATH" FELHOM_HUB_REPO_DIR="$WS/clone" bash ./build.sh 9.9.9 2>&1); rc=$?
    if [[ $rc -eq $2 && "$out" == *"$3"* ]]; then
        echo "  ok  $1 (rc=$rc)"
    else
        echo "  XX  $1 (rc=$rc, expected $2; wanted: $3)"; echo "$out" | tail -8 | sed 's/^/      /'; fails=$((fails+1))
    fi
}

fresh; touch "$WS/clone/leftover.txt"
run "dirty: an untracked file" 1 "the tree is not clean"
fresh; echo b >> "$WS/clone/hub/cmd/hub/a.txt"
run "dirty: a modified tracked file" 1 "the tree is not clean"
fresh; upstream_commit up1; (cd "$WS/clone" && echo l > hub/cmd/hub/local.txt && git add -A && git -c user.name=t -c user.email=t@t commit -q -m local)
run "behind origin and the pull blocked (diverged)" 1 "pull --ff-only failed"
fresh; (cd "$WS/clone" && echo l > hub/cmd/hub/local.txt && git add -A && git -c user.name=t -c user.email=t@t commit -q -m local)
run "ahead of origin (an unpushed commit)" 1 "is not origin/main"
fresh; upstream_commit up2; NEW=$(git -C "$WS/origin.git" rev-parse --short main)
run "behind origin, clean pull: Commit is the NEW head" 0 "Commit:   ${NEW}"
fresh
run "clean, at origin/main: builds (stub docker)" 0 "STUB docker build"

if [[ $fails -gt 0 ]]; then echo "build-hub tree gate: $fails case(s) WRONG"; exit 1; fi
echo "build-hub tree gate OK — 6 case(s)"