#!/usr/bin/env bash
# job-prepare.sh — zet een per-job working tree op
#
# Usage: job-prepare.sh <job_id> <repo_url>
#
# Strategie:
#   1. Bare cache van de repo onderhouden in $AGENT_REPO_CACHE/<slug>.git
#   2. Vers fetchen voor we clonen (laatste main-state)
#   3. `git clone --reference --dissociate` zodat objects gedeeld worden
#      (snelle clone, schone working tree)
#   4. `npm install` met cache-share via $NPM_CONFIG_CACHE
#
# Output (laatste regel): pad van de working tree, voor `cd`-gebruik.

set -uo pipefail

source /opt/agent/bin/_lib.sh

: "${AGENT_REPO_CACHE:=/var/cache/repos}"
: "${AGENT_JOB_ROOT:=/tmp}"
: "${AGENT_LOG_DIR:=/var/log/agent}"

JOB_ID="${1:-}"
REPO_URL="${2:-}"

if [[ -z "$JOB_ID" || -z "$REPO_URL" ]]; then
    log "usage: $0 <job_id> <repo_url>"
    exit 2
fi

# Slug uit repo_url voor de cache-naam: "github.com/foo/bar.git" → "foo_bar"
SLUG=$(echo "$REPO_URL" \
    | sed -E 's#^.*[:/]([^/]+/[^/]+?)(\.git)?/?$#\1#' \
    | tr '/' '_')

CACHE_DIR="${AGENT_REPO_CACHE}/${SLUG}.git"
WORK_DIR="${AGENT_JOB_ROOT}/job-${JOB_ID}"
JOB_LOG="${AGENT_LOG_DIR}/jobs/${JOB_ID}.log"

mkdir -p "$(dirname "$JOB_LOG")"

{
    log "preparing job ${JOB_ID} from ${REPO_URL}"
    log "cache=${CACHE_DIR} work=${WORK_DIR}"

    # ----- 1. ensure bare cache ------------------------------------
    if [[ ! -d "$CACHE_DIR" ]]; then
        log "cache miss — bare-cloning ${REPO_URL}"
        git clone --bare --filter=blob:none "$REPO_URL" "$CACHE_DIR"
    else
        log "cache hit — fetching latest"
        git -C "$CACHE_DIR" fetch --all --prune --quiet
    fi

    # ----- 2. fresh working tree -----------------------------------
    if [[ -d "$WORK_DIR" ]]; then
        log "stale work dir found — removing"
        rm -rf "$WORK_DIR"
    fi

    log "cloning via reference"
    git clone \
        --reference "$CACHE_DIR" \
        --dissociate \
        --quiet \
        "$REPO_URL" "$WORK_DIR"

    # ----- 3. branch -----------------------------------------------
    BRANCH="agent/job-${JOB_ID}"
    git -C "$WORK_DIR" checkout -B "$BRANCH"
    log "checked out ${BRANCH} from $(git -C "$WORK_DIR" rev-parse --short HEAD)"

    # ----- 4. install deps -----------------------------------------
    if [[ -f "$WORK_DIR/package-lock.json" ]]; then
        log "running npm ci (cache=${NPM_CONFIG_CACHE})"
        ( cd "$WORK_DIR" && npm ci --no-audit --no-fund --prefer-offline ) \
            || log "WARN: npm ci failed (continuing — agent kan zelf decide)"
    elif [[ -f "$WORK_DIR/package.json" ]]; then
        log "no lockfile — running npm install"
        ( cd "$WORK_DIR" && npm install --no-audit --no-fund --prefer-offline ) \
            || log "WARN: npm install failed"
    else
        log "no package.json — skipping install"
    fi

    log "ready: ${WORK_DIR}"
} >> "$JOB_LOG" 2>&1

# Output naar stdout zodat Claude het pad kan parsen.
echo "$WORK_DIR"