#!/usr/bin/env bash

set -euo pipefail

SCCACHE_VERSION="v0.10.0"
# Use absolute path to avoid issues with working directory changes between steps
SCCACHE_DIR="$(pwd)/target/sccache"

install_sccache() {
    mkdir -p "$SCCACHE_DIR"

    if [[ -x "${SCCACHE_DIR}/sccache" ]] && "${SCCACHE_DIR}/sccache" --version &>/dev/null; then
        echo "sccache already cached: $("${SCCACHE_DIR}/sccache" --version)"
    else
        echo "Installing sccache ${SCCACHE_VERSION} from GitHub releases..."

        local os arch archive basename
        os="$(uname -s)"
        arch="$(uname -m)"

        case "${os}-${arch}" in
            Darwin-arm64)
                archive="sccache-${SCCACHE_VERSION}-aarch64-apple-darwin.tar.gz"
                ;;
            Darwin-x86_64)
                archive="sccache-${SCCACHE_VERSION}-x86_64-apple-darwin.tar.gz"
                ;;
            Linux-x86_64)
                archive="sccache-${SCCACHE_VERSION}-x86_64-unknown-linux-musl.tar.gz"
                ;;
            Linux-aarch64)
                archive="sccache-${SCCACHE_VERSION}-aarch64-unknown-linux-musl.tar.gz"
                ;;
            *)
                echo "Unsupported platform: ${os}-${arch}"
                exit 1
                ;;
        esac

        basename="${archive%.tar.gz}"
        curl -fsSL "https://github.com/mozilla/sccache/releases/download/${SCCACHE_VERSION}/${archive}" | tar xz
        mv "${basename}/sccache" "${SCCACHE_DIR}/"
        rm -rf "${basename}"
        echo "Installed sccache: $("${SCCACHE_DIR}/sccache" --version)"
    fi

    # Verify the binary works before adding to path
    if ! "${SCCACHE_DIR}/sccache" --version &>/dev/null; then
        echo "ERROR: sccache binary at ${SCCACHE_DIR}/sccache is not executable or corrupted"
        rm -f "${SCCACHE_DIR}/sccache"
        exit 1
    fi

    if [[ -n "${GITHUB_PATH:-}" ]]; then
        echo "${SCCACHE_DIR}" >> "$GITHUB_PATH"
    fi
    export PATH="${SCCACHE_DIR}:${PATH}"
}

configure_sccache() {
    if [[ -z "${R2_ACCOUNT_ID:-}" ]]; then
        echo "R2_ACCOUNT_ID not set, skipping sccache configuration"
        return
    fi

    echo "Configuring sccache with Cloudflare R2..."

    local bucket="${SCCACHE_BUCKET:-sccache-zed}"
    local key_prefix="${SCCACHE_KEY_PREFIX:-sccache/}"
    local base_dir="${GITHUB_WORKSPACE:-$(pwd)}"

    # Use the absolute path to sccache binary for RUSTC_WRAPPER to avoid
    # any PATH race conditions between GITHUB_PATH and GITHUB_ENV
    local sccache_bin="${SCCACHE_DIR}/sccache"

    # Set in current process
    export SCCACHE_ENDPOINT="https://${R2_ACCOUNT_ID}.r2.cloudflarestorage.com"
    export SCCACHE_BUCKET="${bucket}"
    export SCCACHE_REGION="auto"
    export SCCACHE_S3_KEY_PREFIX="${key_prefix}"
    export SCCACHE_BASEDIR="${base_dir}"
    export AWS_ACCESS_KEY_ID="${R2_ACCESS_KEY_ID}"
    export AWS_SECRET_ACCESS_KEY="${R2_SECRET_ACCESS_KEY}"
    export RUSTC_WRAPPER="${sccache_bin}"

    # Also write to GITHUB_ENV for subsequent steps
    if [[ -n "${GITHUB_ENV:-}" ]]; then
        {
            echo "SCCACHE_ENDPOINT=${SCCACHE_ENDPOINT}"
            echo "SCCACHE_BUCKET=${SCCACHE_BUCKET}"
            echo "SCCACHE_REGION=${SCCACHE_REGION}"
            echo "SCCACHE_S3_KEY_PREFIX=${SCCACHE_S3_KEY_PREFIX}"
            echo "SCCACHE_BASEDIR=${SCCACHE_BASEDIR}"
            echo "AWS_ACCESS_KEY_ID=${AWS_ACCESS_KEY_ID}"
            echo "AWS_SECRET_ACCESS_KEY=${AWS_SECRET_ACCESS_KEY}"
            echo "RUSTC_WRAPPER=${RUSTC_WRAPPER}"
        } >> "$GITHUB_ENV"
    fi

    echo "✓ sccache configured with Cloudflare R2 (bucket: ${bucket})"
}

show_config() {
    echo "=== sccache configuration ==="
    echo "sccache version: $(sccache --version)"
    echo "RUSTC_WRAPPER: ${RUSTC_WRAPPER:-<not set>}"
    echo "SCCACHE_BUCKET: ${SCCACHE_BUCKET:-<not set>}"
    echo "SCCACHE_ENDPOINT: ${SCCACHE_ENDPOINT:-<not set>}"
    echo "SCCACHE_REGION: ${SCCACHE_REGION:-<not set>}"
    echo "SCCACHE_S3_KEY_PREFIX: ${SCCACHE_S3_KEY_PREFIX:-<not set>}"
    echo "SCCACHE_BASEDIR: ${SCCACHE_BASEDIR:-<not set>}"
    if [[ -n "${AWS_ACCESS_KEY_ID:-}" ]]; then
        echo "AWS_ACCESS_KEY_ID: <set, length=${#AWS_ACCESS_KEY_ID}>"
    else
        echo "AWS_ACCESS_KEY_ID: <not set>"
    fi
    if [[ -n "${AWS_SECRET_ACCESS_KEY:-}" ]]; then
        echo "AWS_SECRET_ACCESS_KEY: <set>"
    else
        echo "AWS_SECRET_ACCESS_KEY: <not set>"
    fi
    echo "=== sccache stats ==="
    sccache --show-stats || true
}

install_sccache
configure_sccache
show_config