#!/bin/bash
set -euo pipefail

# ===============================
# CONFIGURATION
# ===============================
CLEAN_BUILD="${CLEAN_BUILD:-false}"
HALIUM_REPO="${HALIUM_REPO:-https://gitlab.com/ubports/porting/community-ports/halium-generic-adaptation-build-tools.git}"
HALIUM_BRANCH="${HALIUM_BRANCH:-main}"
WORKDIR="$(pwd)"
OUTDIR="${WORKDIR}/out"
OTADIR="${WORKDIR}/ota"
BUILDDIR="${WORKDIR}/build"

# ===============================
# LOGGING FUNCTIONS
# ===============================
log() {
    echo "[$(date +'%Y-%m-%d %H:%M:%S')] $*" >&2
}

cleanup() {
    local exit_code=$?
    if [ $exit_code -ne 0 ]; then
        log "Build failed with exit code $exit_code"
    fi
}
trap cleanup EXIT

# ===============================
# PREPARE BUILD ENV
# ===============================
if [ "$CLEAN_BUILD" = "true" ]; then
    log "Performing clean build: removing previous artifacts"
    rm -rf "$OUTDIR" "$OTADIR" "$BUILDDIR"
else
    log "Incremental build enabled (set CLEAN_BUILD=true to force wipe)"
fi

mkdir -p "$OUTDIR" "$OTADIR"

# ===============================
# CLONE HALIUM TOOLS
# ===============================
if [ ! -d "$BUILDDIR" ]; then
    log "Cloning Halium build tools from $HALIUM_REPO (branch: $HALIUM_BRANCH)"
    git clone -b "$HALIUM_BRANCH" "$HALIUM_REPO" "$BUILDDIR"
else
    log "Halium build tools already present, pulling latest changes"
    (cd "$BUILDDIR" && git fetch && git checkout "$HALIUM_BRANCH" && git pull --rebase) || true
fi

# ===============================
# BUILD KERNEL
# ===============================
log "Starting kernel build..."
"$BUILDDIR/build.sh"
log "Kernel build completed successfully"

# ===============================
# ROOTFS & OTA PREP
# ===============================
DATETIME=$(date +%Y%m%d-%H%M)
DEVICE="$(source deviceinfo && echo "$deviceinfo_codename")"

log "Preparing OTA for device: $DEVICE"
"$BUILDDIR/prepare-fake-ota.sh" "$OUTDIR/device_${DEVICE}.tar.xz" "$OTADIR"

log "Generating system image..."
"$BUILDDIR/system-image-from-ota.sh" "$OTADIR/ubuntu_command" "$OUTDIR"
mv "$OUTDIR/rootfs.img" "$OUTDIR/ubuntu.img"

# ===============================
# PACKAGE ARTIFACTS
# ===============================
cd "$OUTDIR"
log "Compressing ubuntu.img with zstd..."
rm -f ubuntu.img.zst

log "Cleaning generated {init}/boot artifacts inorder to use prebuilt ones"
rm -rf boot.img init_boot.img

log "Copying prebuilt artifacts"
cp -r ../boot.img .
cp -r ../init_boot.img .

zstd -q -f ubuntu.img

ZIPNAME="ubuntu-touch-${DEVICE}-${DATETIME}.zip"
log "Creating flashable zip: $ZIPNAME"
zip -r9 "$ZIPNAME" boot.img init_boot.img *.zst

cd "$WORKDIR"

# ===============================
# DONE
# ===============================
log "======================================="
log "Build completed successfully!"
log "Artifacts available in: $OUTDIR"
ls -lh "$OUTDIR"
log "======================================="