#!/usr/bin/env bash
#
# Cross-compile pydantic-core for Android ARM64.
#
# Prerequisites:
#   - Rust toolchain (rustup)
#   - Android NDK (set ANDROID_NDK_HOME or let this script find it)
#   - maturin (pip install maturin)
#   - Python 3.11 (matching Chaquopy's embedded version)
#
# Output: ../wheels/pydantic_core-*.whl
#
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
WHEELS_DIR="$SCRIPT_DIR/../wheels"
BUILD_DIR="$SCRIPT_DIR/../.build-cache"

# ── Pydantic-core version (must match pydantic>=2.9.2 requirement) ──
PYDANTIC_CORE_VERSION="2.27.2"

# ── Find Android NDK ────────────────────────────────────────────────
if [ -z "${ANDROID_NDK_HOME:-}" ]; then
    # Try common locations
    for candidate in \
        "$HOME/Library/Android/sdk/ndk"/* \
        "$HOME/Android/Sdk/ndk"/* \
        "$LOCALAPPDATA/Android/Sdk/ndk"/* \
        "/usr/local/lib/android/sdk/ndk"/*; do
        if [ -d "$candidate" ]; then
            ANDROID_NDK_HOME="$candidate"
            break
        fi
    done
fi

if [ -z "${ANDROID_NDK_HOME:-}" ]; then
    echo "ERROR: Android NDK not found. Set ANDROID_NDK_HOME or install via Android Studio."
    exit 1
fi
echo "Using Android NDK: $ANDROID_NDK_HOME"

# ── Determine NDK API level and toolchain ───────────────────────────
API_LEVEL=24
HOST_TAG=""
case "$(uname -s)" in
    Linux*)  HOST_TAG="linux-x86_64" ;;
    Darwin*) HOST_TAG="darwin-x86_64" ;;
    MINGW*|MSYS*|CYGWIN*) HOST_TAG="windows-x86_64" ;;
    *) echo "Unsupported host OS"; exit 1 ;;
esac

TOOLCHAIN="$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/$HOST_TAG"
CC="$TOOLCHAIN/bin/aarch64-linux-android${API_LEVEL}-clang"
AR="$TOOLCHAIN/bin/llvm-ar"

if [ ! -f "$CC" ] && [ ! -f "${CC}.cmd" ]; then
    echo "ERROR: NDK compiler not found at $CC"
    echo "Check your NDK installation."
    exit 1
fi

# ── Install Rust Android target ─────────────────────────────────────
echo "Adding Rust target aarch64-linux-android..."
rustup target add aarch64-linux-android

# ── Configure Cargo for cross-compilation ───────────────────────────
mkdir -p "$BUILD_DIR"
export CARGO_TARGET_AARCH64_LINUX_ANDROID_LINKER="$CC"
export CC_aarch64_linux_android="$CC"
export AR_aarch64_linux_android="$AR"

# ── Clone pydantic-core ─────────────────────────────────────────────
REPO_DIR="$BUILD_DIR/pydantic-core"
if [ -d "$REPO_DIR" ]; then
    echo "Updating existing pydantic-core checkout..."
    cd "$REPO_DIR"
    git fetch --tags
    git checkout "v$PYDANTIC_CORE_VERSION"
else
    echo "Cloning pydantic-core v$PYDANTIC_CORE_VERSION..."
    git clone --depth 1 --branch "v$PYDANTIC_CORE_VERSION" \
        https://github.com/pydantic/pydantic-core.git "$REPO_DIR"
    cd "$REPO_DIR"
fi

# ── Build with maturin ──────────────────────────────────────────────
echo "Building pydantic-core for aarch64-linux-android..."
maturin build \
    --release \
    --target aarch64-linux-android \
    --interpreter python3.11 \
    --out "$WHEELS_DIR"

echo ""
echo "=== Build complete ==="
echo "Wheels:"
ls -la "$WHEELS_DIR"/pydantic_core-*.whl 2>/dev/null || echo "WARNING: No wheel found!"