#!/bin/bash
#
# Copyright 2026 Aarav Ravindra Kharade
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

# ═══════════════════════════════════════════════════════════════════
#  ArkOS Build Environment Setup
# ═══════════════════════════════════════════════════════════════════
#
#  Usage:
#    source envsetup.sh
#    type arm64          # Select ARM64 target (Raspberry Pi 4)
#    type x86_64         # Select x86_64 target (PC / QEMU)
#    make                # Build for the selected target
#
#  This script mirrors Android's envsetup.sh / lunch workflow.
#  It must be sourced (not executed) so functions persist in your
#  shell session.
#
# ═══════════════════════════════════════════════════════════════════

# Detect the directory this script lives in
export ARKOS_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
export ARKOS_REPO="$(cd "$ARKOS_ROOT/.." && pwd)"
export ARKOS_TOOLS="$ARKOS_REPO/tools"
export ARKOS_OUT="$ARKOS_ROOT/out_staging"
export ARKOS_FINISHED="$ARKOS_ROOT/finished"

# ── Host Architecture Detection ───────────────────────────────────

export HOST_ARCH="$(uname -m)"
case "$HOST_ARCH" in
    x86_64|amd64)  HOST_ARCH="x86_64" ;;
    aarch64|arm64) HOST_ARCH="aarch64" ;;
    *)             HOST_ARCH="x86_64" ;;
esac
export HOST_ARCH

# ── Clang Toolchain ───────────────────────────────────────────────

# Prefer the prebuilt clang shipped with ArkOS, fall back to system clang
if [ -x "$ARKOS_ROOT/prebuilts/clang/bin/clang" ]; then
    export ARKOS_CLANG="$ARKOS_ROOT/prebuilts/clang/bin/clang"
    export ARKOS_CLANGXX="$ARKOS_ROOT/prebuilts/clang/bin/clang++"
else
    export ARKOS_CLANG="$(which clang 2>/dev/null || echo clang)"
    export ARKOS_CLANGXX="$(which clang++ 2>/dev/null || echo clang++)"
fi

# ── type() — Target Architecture Selector ─────────────────────────
#
#  Works like Android's lunch command. Sets all compiler variables
#  for the selected target architecture.
#
#  Supported targets:
#    arm64   — Raspberry Pi 4 (aarch64-linux-gnu)
#    x86_64  — Standard PC / QEMU (x86_64-linux-gnu)

function type() {
    local target="$1"

    if [ -z "$target" ]; then
        echo ""
        echo "  Usage: type <target>"
        echo ""
        echo "  Available targets:"
        echo "    arm64    — Raspberry Pi 4 Model B (aarch64-linux-gnu)"
        echo "    x86_64   — Standard PC / QEMU (x86_64-linux-gnu)"
        echo ""
        return 1
    fi

    case "$target" in
        arm64|aarch64)
            export TARGET_ARCH="aarch64"
            export TARGET_TRIPLE="aarch64-linux-gnu"
            export TARGET_DEVICE="rpi4"
            export TARGET_KERNEL="arm64"
            export TARGET_KERNEL_IMAGE="Image"
            export TARGET_SYSROOT="$ARKOS_ROOT/system/sysrootaarch64"
            export TARGET_MODULES_DIR="$ARKOS_ROOT/system/sysrootaarch64"
            export TARGET_SWIFT_TRIPLE="aarch64-swift-linux-musl"
            export TARGET_QEMU="qemu-system-aarch64"
            ;;
        x86_64|x86|amd64)
            export TARGET_ARCH="x86_64"
            export TARGET_TRIPLE="x86_64-linux-gnu"
            export TARGET_DEVICE="generic"
            export TARGET_KERNEL="x86_64"
            export TARGET_KERNEL_IMAGE="bzImage"
            export TARGET_SYSROOT="$ARKOS_ROOT/system/sysroot"
            export TARGET_MODULES_DIR="$ARKOS_ROOT/system/ark-sysroot"
            export TARGET_SWIFT_TRIPLE="x86_64-unknown-linux-gnu"
            export TARGET_QEMU="qemu-system-x86_64"
            ;;
        *)
            echo ""
            echo "  ✗ Unknown target: '$target'"
            echo "  Supported targets: arm64, x86_64"
            echo ""
            return 1
            ;;
    esac

    # Set compiler variables — everything uses clang
    export CC="$ARKOS_CLANG --target=$TARGET_TRIPLE"
    export CXX="$ARKOS_CLANGXX --target=$TARGET_TRIPLE"
    export AR="llvm-ar"
    export LD="ld.lld"
    export OBJCOPY="llvm-objcopy"
    export STRIP="llvm-strip"

    # Mark that a target has been selected
    export ARKOS_TARGET_SET=1

    # Print selection banner
    echo ""
    echo -e "  \033[1;36m╔══════════════════════════════════════════╗\033[0m"
    echo -e "  \033[1;36m║       ArkOS Build Target Selected        ║\033[0m"
    echo -e "  \033[1;36m╠══════════════════════════════════════════╣\033[0m"
    echo -e "  \033[1;36m║\033[0m  Architecture : \033[1;32m$TARGET_ARCH\033[0m"
    echo -e "  \033[1;36m║\033[0m  Triple       : \033[1;33m$TARGET_TRIPLE\033[0m"
    echo -e "  \033[1;36m║\033[0m  Device       : \033[1;35m$TARGET_DEVICE\033[0m"
    echo -e "  \033[1;36m║\033[0m  Kernel       : \033[0;37m$TARGET_KERNEL_IMAGE\033[0m"
    echo -e "  \033[1;36m║\033[0m  Sysroot      : \033[0;37m$TARGET_SYSROOT\033[0m"
    echo -e "  \033[1;36m║\033[0m  Compiler     : \033[0;37mclang ($ARKOS_CLANG)\033[0m"
    echo -e "  \033[1;36m╚══════════════════════════════════════════╝\033[0m"
    echo ""
    echo -e "  Run \033[1mmake\033[0m to build ArkOS for \033[1m$TARGET_ARCH\033[0m."
    echo ""
}

# ── Helper Functions ──────────────────────────────────────────────

function croot() {
    cd "$ARKOS_ROOT"
}

function cout() {
    cd "$ARKOS_OUT"
}

function goarkrt() {
    cd "$ARKOS_ROOT/arkrt"
}

# ── Startup Banner ────────────────────────────────────────────────

echo ""
echo -e "  \033[1;35m╔══════════════════════════════════════════╗\033[0m"
echo -e "  \033[1;35m║     ArkOS Build Environment v4.0         ║\033[0m"
echo -e "  \033[1;35m║     Host: $HOST_ARCH                          ║\033[0m"
echo -e "  \033[1;35m╚══════════════════════════════════════════╝\033[0m"
echo ""
echo -e "  Commands:"
echo -e "    \033[1mtype arm64\033[0m   — Select ARM64 target (RPi4)"
echo -e "    \033[1mtype x86_64\033[0m  — Select x86_64 target (PC)"
echo -e "    \033[1mmake\033[0m         — Build for selected target"
echo -e "    \033[1mcroot\033[0m        — cd to ArkOS root"
echo ""