#!/usr/bin/env bash
set -euo pipefail

DRY_RUN=false

while [[ $# -gt 0 ]]; do
    case $1 in
        --dry-run|-n)
            DRY_RUN=true
            shift
            ;;
        --help|-h)
            echo "Usage: $0 [OPTIONS]"
            echo ""
            echo "Options:"
            echo "  --dry-run, -n    Show what would be updated without making changes"
            echo "  --help, -h       Show this help message"
            exit 0
            ;;
        *)
            echo "Unknown option: $1"
            echo "Use --help for usage information"
            exit 1
            ;;
    esac
done

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

REPO_ROOT="${REPO_ROOT:-$(git rev-parse --show-toplevel 2>/dev/null || pwd)}"
NIX_FILE="$REPO_ROOT/packages/opencode/default.nix"

echo "Fetching latest opencode version from GitHub API..."

RELEASE_INFO=$(curl -fsSL https://api.github.com/repos/anomalyco/opencode/releases/latest)
NEW_VERSION=$(echo "$RELEASE_INFO" | jq -r '.tag_name' | sed 's/^v//')

if [ -z "$NEW_VERSION" ] || [ "$NEW_VERSION" = "null" ]; then
    echo -e "${RED}Error: Failed to fetch version from GitHub API${NC}"
    exit 1
fi

CURRENT_VERSION=$(grep -m1 'version = ' "$NIX_FILE" | sed -E 's/.*version = "([^"]+)".*/\1/')

if [ "$CURRENT_VERSION" = "$NEW_VERSION" ]; then
    echo -e "${GREEN}Already up to date: $CURRENT_VERSION${NC}"
    exit 0
fi

echo -e "${YELLOW}Updating from $CURRENT_VERSION to $NEW_VERSION${NC}"

# Compute SHA256 hashes for each platform
# fetchzip hashes the unpacked directory, so we need to extract and hash
compute_unpacked_hash() {
    local url="$1"
    local ext="$2"
    local tmpdir=$(mktemp -d)
    local archive="/tmp/opencode-archive.$ext"
    
    curl -fsSL "$url" -o "$archive"
    
    if [ "$ext" = "zip" ]; then
        (cd "$tmpdir" && unzip -q "$archive")
    else
        (cd "$tmpdir" && tar xzf "$archive")
    fi
    
    local sri_hash=$(nix hash path "$tmpdir")
    local nix32_hash=$(nix hash convert --hash-algo sha256 --to nix32 "$sri_hash")
    
    rm -rf "$tmpdir" "$archive"
    echo "$nix32_hash"
}

echo "Computing SHA256 hashes (this may take a moment)..."

SHA_DARWIN_ARM=$(compute_unpacked_hash "https://github.com/anomalyco/opencode/releases/download/v${NEW_VERSION}/opencode-darwin-arm64.zip" "zip")
echo "  aarch64-darwin: $SHA_DARWIN_ARM"

SHA_DARWIN_X64=$(compute_unpacked_hash "https://github.com/anomalyco/opencode/releases/download/v${NEW_VERSION}/opencode-darwin-x64.zip" "zip")
echo "  x86_64-darwin: $SHA_DARWIN_X64"

SHA_LINUX_X64=$(compute_unpacked_hash "https://github.com/anomalyco/opencode/releases/download/v${NEW_VERSION}/opencode-linux-x64.tar.gz" "tar.gz")
echo "  x86_64-linux: $SHA_LINUX_X64"

SHA_LINUX_ARM64=$(compute_unpacked_hash "https://github.com/anomalyco/opencode/releases/download/v${NEW_VERSION}/opencode-linux-arm64.tar.gz" "tar.gz")
echo "  aarch64-linux: $SHA_LINUX_ARM64"

if [ "$DRY_RUN" = true ]; then
    echo -e "${YELLOW}DRY RUN - No changes will be made${NC}"
    echo ""
    echo "Would update:"
    echo "  Version: $CURRENT_VERSION -> $NEW_VERSION"
    echo "  aarch64-darwin SHA: $SHA_DARWIN_ARM"
    echo "  x86_64-darwin SHA:  $SHA_DARWIN_X64"
    echo "  x86_64-linux SHA:   $SHA_LINUX_X64"
    echo "  aarch64-linux SHA:  $SHA_LINUX_ARM64"
    exit 0
fi

# Update version
sed -i.tmp "s/version = \".*\";/version = \"$NEW_VERSION\";/" "$NIX_FILE"

# Update SHA256 hashes using awk
awk -v sha_arm="$SHA_DARWIN_ARM" -v sha_x64="$SHA_DARWIN_X64" -v sha_linux_x64="$SHA_LINUX_X64" -v sha_linux_arm="$SHA_LINUX_ARM64" '
/aarch64-darwin = {/ { in_arm = 1 }
/x86_64-darwin = {/ { in_x64 = 1; in_arm = 0 }
/x86_64-linux = {/ { in_linux_x64 = 1; in_x64 = 0 }
/aarch64-linux = {/ { in_linux_arm = 1; in_linux_x64 = 0 }
/};/ {
  in_arm = 0
  in_x64 = 0
  in_linux_x64 = 0
  in_linux_arm = 0
}
/sha256 = / {
  if (in_arm) {
    sub(/sha256 = ".*";/, "sha256 = \"" sha_arm "\";")
  } else if (in_x64) {
    sub(/sha256 = ".*";/, "sha256 = \"" sha_x64 "\";")
  } else if (in_linux_x64) {
    sub(/sha256 = ".*";/, "sha256 = \"" sha_linux_x64 "\";")
  } else if (in_linux_arm) {
    sub(/sha256 = ".*";/, "sha256 = \"" sha_linux_arm "\";")
  }
}
{ print }
' "$NIX_FILE" > "$NIX_FILE.new"

mv "$NIX_FILE.new" "$NIX_FILE"
rm -f "$NIX_FILE.tmp"

echo -e "${GREEN}Successfully updated to version $NEW_VERSION${NC}"
echo ""
echo "Updated SHA256 hashes:"
echo "  aarch64-darwin: $SHA_DARWIN_ARM"
echo "  x86_64-darwin:  $SHA_DARWIN_X64"
echo "  x86_64-linux:   $SHA_LINUX_X64"
echo "  aarch64-linux:  $SHA_LINUX_ARM64"
echo ""
echo "Next steps:"
echo "  1. Review changes: git diff $NIX_FILE"
echo "  2. Test build: nix build .#custom-opencode"
echo "  3. Verify version: ./result/bin/opencode --version"
echo "  4. Commit: git add $NIX_FILE && git commit -m 'opencode: Update to version $NEW_VERSION'"