#!/bin/sh
set -e

# Vikasit Code Installer
# Usage: curl -fsSL https://vikasit.ai/install | sh
# Windows users: run  irm https://vikasit.ai/install.ps1 | iex

REPO="Vikasit-AI/releases"
BINARY="vikasit"

# Detect OS and architecture
detect_platform() {
  OS=$(uname -s | tr '[:upper:]' '[:lower:]')
  ARCH=$(uname -m)

  # Messages here MUST go to stderr. This function is called as
  # PLATFORM=$(detect_platform), so anything on stdout is captured into the
  # variable instead of shown — which silently hid the Windows hint below.
  case "$OS" in
    linux) OS="linux" ;;
    darwin) OS="darwin" ;;
    # Git Bash / MSYS2 / Cygwin report MINGW64_NT-*, MSYS_NT-*, CYGWIN_NT-*.
    # They can run this script but there is no POSIX build for them; point at
    # the PowerShell installer, which fetches the native windows-*.zip.
    mingw*|msys*|cygwin*|windows*)
      echo "Vikasit Code has a native Windows build; this POSIX installer cannot install it." >&2
      echo "" >&2
      echo "Run this in PowerShell instead:" >&2
      echo "" >&2
      echo "  irm https://vikasit.ai/install.ps1 | iex" >&2
      echo "" >&2
      exit 1 ;;
    *)
      echo "Unsupported OS: $OS" >&2
      echo "Windows users: run  irm https://vikasit.ai/install.ps1 | iex" >&2
      exit 1 ;;
  esac

  case "$ARCH" in
    x86_64|amd64) ARCH="x64" ;;
    aarch64|arm64) ARCH="arm64" ;;
    *) echo "Unsupported architecture: $ARCH" >&2; exit 1 ;;
  esac

  # The default x64 build is compiled with AVX2. On a pre-Haswell CPU (roughly
  # pre-2013) it installs fine and then panics on every run, which reads as a
  # broken install rather than an unsupported CPU. Fall back to the -baseline
  # build, which exists for those machines. arm64 is unaffected.
  if [ "$ARCH" = "x64" ]; then
    HAS_AVX2=""
    if [ "$OS" = "linux" ] && [ -r /proc/cpuinfo ]; then
      HAS_AVX2=$(grep -m1 -o ' avx2' /proc/cpuinfo 2>/dev/null || true)
    elif [ "$OS" = "darwin" ]; then
      HAS_AVX2=$(sysctl -n machdep.cpu.leaf7_features 2>/dev/null | grep -o 'AVX2' || true)
    fi
    # Only downgrade when the probe ran AND reported no AVX2. If the probe
    # itself could not run, assume AVX2 so modern machines are unaffected.
    if [ -z "$HAS_AVX2" ] && { [ -r /proc/cpuinfo ] || [ "$OS" = "darwin" ]; }; then
      ARCH="x64-baseline"
      echo "CPU has no AVX2 - using the baseline build." >&2
    fi
  fi

  echo "${OS}-${ARCH}"
}

# Get latest version from GitHub (robust parse: tolerant of spacing/order)
get_latest_version() {
  curl -fsSL "https://api.github.com/repos/$REPO/releases/latest" \
    | grep '"tag_name"' \
    | head -n 1 \
    | sed -E 's/.*"tag_name"[[:space:]]*:[[:space:]]*"v?([^"]+)".*/\1/'
}

PLATFORM=$(detect_platform)
VERSION=$(get_latest_version)

if [ -z "$VERSION" ]; then
  echo "Failed to fetch latest version from https://api.github.com/repos/$REPO/releases/latest"
  exit 1
fi

echo "Installing Vikasit Code v$VERSION for $PLATFORM..."

# Determine file extension
case "$PLATFORM" in
  linux-*) EXT="tar.gz" ;;
  darwin-*) EXT="zip" ;;
esac

URL="https://github.com/$REPO/releases/download/v$VERSION/vikasit-code-$PLATFORM.$EXT"
INSTALL_DIR="$HOME/.vikasit/bin"
TMP_DIR=$(mktemp -d)

echo "Downloading from $URL..."
if ! curl -fSL "$URL" -o "$TMP_DIR/vikasit.$EXT"; then
  echo ""
  echo "ERROR: Failed to download release asset (it may not exist for this version/platform)."
  echo "  Expected asset: vikasit-code-$PLATFORM.$EXT"
  echo "  URL: $URL"
  echo "  Check available downloads at https://github.com/$REPO/releases/tag/v$VERSION"
  rm -rf "$TMP_DIR"
  exit 1
fi

echo "Extracting..."
cd "$TMP_DIR"
case "$EXT" in
  tar.gz) tar xzf "vikasit.$EXT" ;;
  zip) unzip -q "vikasit.$EXT" ;;
esac

echo "Installing to $INSTALL_DIR..."
mkdir -p "$INSTALL_DIR"
mv "$BINARY" "$INSTALL_DIR/$BINARY"
chmod +x "$INSTALL_DIR/$BINARY"

# Ensure install dir is on PATH so `vikasit` resolves and self-update works
# without sudo (the updater re-runs this installer into the same user dir).
case ":$PATH:" in
  *":$INSTALL_DIR:"*) ;;
  *)
    SHELL_RC="$HOME/.profile"
    [ -n "$ZSH_VERSION" ] && SHELL_RC="$HOME/.zshrc"
    [ -n "$BASH_VERSION" ] && SHELL_RC="$HOME/.bashrc"
    if ! grep -qs ".vikasit/bin" "$SHELL_RC"; then
      printf '\nexport PATH="%s:$PATH"\n' "$INSTALL_DIR" >> "$SHELL_RC"
    fi
    echo "Added $INSTALL_DIR to PATH in $SHELL_RC. Restart your shell or run: export PATH=\"$INSTALL_DIR:\$PATH\""
    ;;
esac

# Cleanup
rm -rf "$TMP_DIR"

echo ""
echo "Vikasit Code v$VERSION installed successfully!"
echo ""
echo "Run 'vikasit' to get started."