#!/usr/bin/env bash
# Chanora Linux build helper.
#
# Run this on a Linux host (Ubuntu 22.04+ / Debian bookworm+ / Fedora 38+) that
# has already completed the prerequisites in §4 of docs/release/linux-build.md:
#   - Rust stable with x86_64-unknown-linux-gnu target
#   - Flutter 3.41.9+ stable on PATH
#   - CMake 3.13+, pkg-config, GTK3 dev headers, clang
#   - System libopus dev package (libopus-dev / opus-devel)
#   - flutter_rust_bridge_codegen 2.12.0 (only if regenerating bindings)
#
# Usage (from the repo root ~/chanora):
#   ./tools/build-linux.sh
#   ./tools/build-linux.sh --no-rust          # skip Rust rebuild (cached)
#   ./tools/build-linux.sh --regenerate-bindings  # rerun FRB codegen first
#   ./tools/build-linux.sh --version v0.2.0-beta.1
#
# Produces:
#   target/x86_64-unknown-linux-gnu/release/libchanora_bridge.so
#   apps/chanora_flutter/build/linux/x64/release/bundle/chanora_flutter
#   chanora-<version>-linux-x64.tar.gz          (release bundle)

set -euo pipefail

VERSION="v0.2.0-beta.1"
SKIP_RUST=0
REGEN=0
TARGET="x86_64-unknown-linux-gnu"

while [[ $# -gt 0 ]]; do
    case "$1" in
        --version) VERSION="$2"; shift 2;;
        --no-rust) SKIP_RUST=1; shift;;
        --regenerate-bindings) REGEN=1; shift;;
        --target) TARGET="$2"; shift 2;;
        *) echo "unknown arg: $1" >&2; exit 2;;
    esac
done

cd "$(dirname "$0")/.."
REPO_ROOT="$(pwd)"

bar() { printf '%s\n' '========================================================================'; }

bar
echo "Chanora Linux build"
echo "Repo root : $REPO_ROOT"
echo "Version   : $VERSION"
echo "Target    : $TARGET"
echo "Build Rust: $([ "$SKIP_RUST" = 1 ] && echo skip || echo yes)"
bar

# ---------- 1. Verify toolchain ----------
echo "[1/6] Verify toolchain"
for cmd in cargo rustc flutter cmake pkg-config clang gcc; do
    if ! command -v "$cmd" >/dev/null; then
        echo "  ERROR: '$cmd' not on PATH. See docs/release/linux-build.md." >&2
        exit 1
    fi
    printf "  %-12s : %s\n" "$cmd" "$($cmd --version 2>&1 | head -1)"
done

# Verify GTK3 dev headers
if ! pkg-config --exists gtk+-3.0 2>/dev/null; then
    echo "  ERROR: gtk+-3.0 dev headers not found. Install libgtk-3-dev (Debian/Ubuntu) or gtk3-devel (Fedora)." >&2
    exit 1
fi

# Verify libopus dev headers (needed by audiopus_sys to link)
if ! pkg-config --exists opus 2>/dev/null; then
    echo "  ERROR: opus dev headers not found. Install libopus-dev (Debian/Ubuntu) or opus-devel (Fedora)." >&2
    exit 1
fi

# Verify Rust target
if ! rustup target list --installed | grep -q "^$TARGET$"; then
    echo "  Adding rustup target $TARGET..."
    rustup target add "$TARGET"
fi

# ---------- 2. Add Linux platform if missing ----------
FLUTTER_APP="$REPO_ROOT/apps/chanora_flutter"
if [[ ! -d "$FLUTTER_APP/linux" ]]; then
    echo "[2/6] Add Linux platform to apps/chanora_flutter"
    (cd "$FLUTTER_APP" && flutter create --platforms=linux .)
else
    echo "[2/6] Linux platform already present in apps/chanora_flutter"
fi

# ---------- 3. (Optional) regenerate FRB bindings ----------
if [[ $REGEN -eq 1 ]]; then
    echo "[3/6] Regenerate flutter_rust_bridge bindings"
    if ! command -v flutter_rust_bridge_codegen >/dev/null; then
        echo "  flutter_rust_bridge_codegen not on PATH; install it first." >&2
        exit 1
    fi
    flutter_rust_bridge_codegen generate
else
    echo "[3/6] Skipping FRB codegen (use --regenerate-bindings if api.rs changed)"
fi

# ---------- 4. Build the Rust cdylib ----------
BRIDGE_SO="$REPO_ROOT/target/$TARGET/release/libchanora_bridge.so"

if [[ $SKIP_RUST -eq 1 ]]; then
    echo "[4/6] Skipping Rust build (cached)"
    if [[ ! -f "$BRIDGE_SO" ]]; then
        echo "  ERROR: --no-rust but $BRIDGE_SO not found. Run without --no-rust first." >&2
        exit 1
    fi
else
    echo "[4/6] cargo build --release -p chanora_bridge --target $TARGET"
    export CMAKE_POLICY_VERSION_MINIMUM=3.5
    export LIBOPUS_STATIC=0
    cargo build --release --target "$TARGET" -p chanora_bridge
fi

echo "  Bridge .so: $BRIDGE_SO"
if [[ ! -f "$BRIDGE_SO" ]]; then
    echo "  ERROR: $BRIDGE_SO not found after build." >&2
    exit 1
fi

# ---------- 5. flutter build linux --release ----------
echo "[5/6] flutter build linux --release"
cd "$FLUTTER_APP"
flutter pub get
flutter build linux --release

BUNDLE_DIR="$FLUTTER_APP/build/linux/x64/release/bundle"
EXE="$BUNDLE_DIR/chanora_flutter"
if [[ ! -f "$EXE" ]]; then
    echo "  ERROR: $EXE not found after flutter build." >&2
    exit 1
fi

# Copy the bridge .so into the bundle's lib/ directory so dart:ffi finds it.
mkdir -p "$BUNDLE_DIR/lib"
cp "$BRIDGE_SO" "$BUNDLE_DIR/lib/"
echo "  Bundle dir : $BUNDLE_DIR"
echo "  EXE        : $EXE"
echo "  Bridge .so : $BUNDLE_DIR/lib/libchanora_bridge.so"

# ---------- 6. Package the bundle ----------
echo "[6/6] Package release tarball"
cd "$REPO_ROOT"
TAR_NAME="chanora-$VERSION-linux-x64.tar.gz"
TAR_PATH="$REPO_ROOT/$TAR_NAME"
rm -f "$TAR_PATH"

# Bundle everything in the bundle directory
tar czf "$TAR_PATH" -C "$FLUTTER_APP/build/linux/x64/release/bundle" .
echo "  Tarball    : $TAR_PATH"
echo "  Size       : $(du -h "$TAR_PATH" | cut -f1)"

bar
echo "Linux build complete."
bar
echo "Artefacts:"
echo "  Rust lib:"
echo "    target/$TARGET/release/libchanora_bridge.so"
echo "  Bundle dir:"
echo "    $BUNDLE_DIR/"
echo "  Tarball:"
echo "    $TAR_PATH"