# Shared helpers for all install scripts. Sourced, not executed.

set -euo pipefail

PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
TOOLS_DIR="$PROJECT_ROOT/tools"
DOWNLOAD_CACHE="$PROJECT_ROOT/.cache/downloads"

# The llvm-mos clone our backend is stitched into, and its build tree.
# The clone is pinned to the commit in llvmMosCommit.txt so a fresh
# install builds exactly what we last tested; updateLlvmMos.sh moves the
# pin forward.
LLVM_SRC="$TOOLS_DIR/llvm-mos"
LLVM_BUILD="$TOOLS_DIR/llvm-mos-build"
LLVM_MOS_URL="https://github.com/llvm-mos/llvm-mos.git"
LLVM_MOS_COMMIT_FILE="$PROJECT_ROOT/llvmMosCommit.txt"

install -d "$TOOLS_DIR" "$DOWNLOAD_CACHE"

log() {
    printf '\033[1;34m[llvm816]\033[0m %s\n' "$*" >&2
}

warn() {
    printf '\033[1;33m[llvm816 WARN]\033[0m %s\n' "$*" >&2
}

die() {
    printf '\033[1;31m[llvm816 FAIL]\033[0m %s\n' "$*" >&2
    exit 1
}

# Download to cache unless already present. $1=url, $2=dest filename in cache.
fetchCached() {
    local url="$1"
    local name="$2"
    local dest="$DOWNLOAD_CACHE/$name"
    if [ -s "$dest" ]; then
        log "cached: $name"
    else
        log "fetching: $url"
        curl -fL --retry 3 --progress-bar -o "$dest.part" "$url"
        mv "$dest.part" "$dest"
    fi
    printf '%s\n' "$dest"
}

needCmd() {
    command -v "$1" >/dev/null 2>&1 || die "required command not found: $1"
}

haveCmd() {
    command -v "$1" >/dev/null 2>&1
}

# Print the llvm-mos commit this tree is pinned to.
llvmMosPinnedCommit() {
    local commit
    [ -s "$LLVM_MOS_COMMIT_FILE" ] || die "missing pin file: $LLVM_MOS_COMMIT_FILE"
    commit="$(tr -d '[:space:]' < "$LLVM_MOS_COMMIT_FILE")"
    [[ "$commit" =~ ^[0-9a-f]{40}$ ]] || die "bad commit in $LLVM_MOS_COMMIT_FILE: '$commit'"
    printf '%s\n' "$commit"
}

# Shallow-fetch $1 (a commit SHA) and check it out as local branch main.
# The clone must already have its backend unapplied (unapplyBackend).
checkoutLlvmMosCommit() {
    local commit="$1"
    git -C "$LLVM_SRC" fetch --depth=1 origin "$commit"
    git -C "$LLVM_SRC" checkout -q -B main FETCH_HEAD
}

# Undo applyBackend.sh so the clone is a pristine upstream tree again:
# reverse our patches, then delete the symlinks into src/.  Dies if the
# clone still has changes afterwards (someone edited it by hand).
unapplyBackend() {
    local patch
    local link
    local target
    log "reverting any applied patches"
    for patch in "$PROJECT_ROOT"/patches/*.patch; do
        [ -f "$patch" ] || continue
        if git -C "$LLVM_SRC" apply --reverse --check "$patch" >/dev/null 2>&1; then
            git -C "$LLVM_SRC" apply --reverse "$patch"
            log "  reverted: $(basename "$patch")"
        fi
    done
    # Symlinks from applyBackend.sh are untracked files inside tracked
    # directories; git leaves them alone, so remove them explicitly.
    log "removing symlinks under $LLVM_SRC pointing into $PROJECT_ROOT/src"
    find "$LLVM_SRC" -type l | while read -r link; do
        target="$(readlink -f "$link" || true)"
        case "$target" in
            "$PROJECT_ROOT"/src/*) rm "$link" ;;
        esac
    done
    if ! git -C "$LLVM_SRC" diff --quiet || ! git -C "$LLVM_SRC" diff --cached --quiet; then
        die "llvm-mos checkout still has local changes after cleanup. Inspect with: git -C $LLVM_SRC status"
    fi
}

# runGnoMameSmoke <omf-path> <marker1> [<marker2> ...]
#
# Launch an already-built GNO/ME OMF under real GS/OS 6.0.4 + GNO in
# headless MAME and assert that every <marker> matches.  Each marker is
# a single `addr=hexValue` token in the runInGno.sh `--check` syntax
# (e.g. `0x025000=C0DE`).  Multiple markers are passed positionally —
# the function does NOT split on commas, so a caller wanting two checks
# passes two separate args.
#
# Exit 0 on all-match, 1 on any miss.  Mirrors tests/lua/runLuaTest.sh's
# pattern of "run program in emulator, then assert canned markers";
# scoped at GNO instead of bare-metal because the C++ smoke / cxxstdlib
# / cursor work needs a real OMF Loader path.
#
# Required prereqs (caller should pre-check or let this function die):
#   tools/cadius/cadius
#   tools/gsos/6.0.4 - System.Disk.po
#   tools/gno/gnobase.po
runGnoMameSmoke() {
    local omfPath="$1"
    shift
    [ -f "$omfPath" ] || die "runGnoMameSmoke: OMF not found: $omfPath"
    [ $# -ge 1 ]      || die "runGnoMameSmoke: at least one marker required"
    local args=()
    local m
    for m in "$@"; do
        args+=("$m")
    done
    bash "$PROJECT_ROOT/scripts/runInGno.sh" "$omfPath" --check "${args[@]}"
}