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

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
TAURI_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"
REPO_ROOT="$(cd "$TAURI_DIR/.." && pwd)"

detect_host_triple() {
  if ! command -v rustc >/dev/null 2>&1; then
    echo "error: rustc is required to determine the host target triple" >&2
    return 1
  fi
  local host
  host="$(rustc -vV | awk '/^host: /{print $2}')"
  if [ -z "$host" ]; then
    echo "error: could not determine host target triple" >&2
    return 1
  fi
  echo "$host"
}

resolve_target_triple() {
  if [ -n "${TAURI_ENV_TARGET_TRIPLE:-}" ]; then
    echo "$TAURI_ENV_TARGET_TRIPLE"
    return 0
  fi
  if [ -n "${CARGO_BUILD_TARGET:-}" ]; then
    echo "$CARGO_BUILD_TARGET"
    return 0
  fi
  detect_host_triple
}

map_go_target() {
  case "$1" in
    aarch64-apple-darwin) echo "darwin arm64" ;;
    x86_64-apple-darwin) echo "darwin amd64" ;;
    x86_64-pc-windows-msvc|x86_64-pc-windows-gnu) echo "windows amd64" ;;
    aarch64-pc-windows-msvc) echo "windows arm64" ;;
    x86_64-unknown-linux-gnu) echo "linux amd64" ;;
    aarch64-unknown-linux-gnu) echo "linux arm64" ;;
    *)
      echo "error: unsupported target triple for Go sidecar: $1" >&2
      return 1
      ;;
  esac
}

resolve_version() {
  # In CI, AGENTSVIEW_VERSION is set from the triggering tag ref
  # to avoid git-describe picking the wrong tag when multiple
  # tags point at the same commit.
  if [ -n "${AGENTSVIEW_VERSION:-}" ]; then
    echo "$AGENTSVIEW_VERSION"
    return 0
  fi

  local resolved
  resolved="$(git -C "$REPO_ROOT" describe --tags --always --dirty 2>/dev/null || true)"
  if [ -n "$resolved" ]; then
    echo "$resolved"
    return 0
  fi

  resolved="$(git -C "$REPO_ROOT" rev-parse --short HEAD 2>/dev/null || true)"
  if [ -n "$resolved" ]; then
    echo "$resolved"
    return 0
  fi

  echo "dev"
}

version_to_semver() {
  local raw="$1"
  # Strip leading 'v'
  raw="${raw#v}"
  # git-describe: 0.10.0-3-gabcdef -> 0.10.0-dev.3
  if [[ "$raw" =~ ^([0-9]+\.[0-9]+\.[0-9]+)-([0-9]+)-g[0-9a-f]+(-dirty)?$ ]]; then
    local base="${BASH_REMATCH[1]}"
    local distance="${BASH_REMATCH[2]}"
    echo "${base}-dev.${distance}"
    return 0
  fi
  # Already semver, with optional prerelease suffix (possibly with -dirty).
  # Identifiers are dot-separated, each non-empty, allowing [a-zA-Z0-9-].
  if [[ "$raw" =~ ^[0-9]+\.[0-9]+\.[0-9]+(-[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)*)?(-dirty)?$ ]]; then
    echo "${raw%-dirty}"
    return 0
  fi
  # Looks like a version (digits then dot) but isn't valid semver -- fail fast.
  # Bare hex hashes starting with digits (e.g. 1abc234) fall through to
  # the non-tag fallback below.
  if [[ "$raw" =~ ^[0-9]+\. ]]; then
    echo "error: malformed version tag: $raw" >&2
    return 1
  fi
  # Non-tag fallback: bare hash, "dev", etc.
  echo ""
}

patch_tauri_version() {
  local version="$1"
  local semver
  semver="$(version_to_semver "$version")"
  if [ -z "$semver" ]; then
    echo "Skipping tauri.conf.json version patch (non-tag build: $version)"
    return 0
  fi
  local conf="$TAURI_DIR/src-tauri/tauri.conf.json"
  # Save original only if not already saved (handles re-run
  # after a previous failure left the backup behind).
  if [ ! -f "$conf.orig" ]; then
    cp "$conf" "$conf.orig"
  fi
  sed -i.bak \
    "s/\"version\": \"[^\"]*\"/\"version\": \"$semver\"/" \
    "$conf"
  rm -f "$conf.bak"
  echo "Patched tauri.conf.json version to $semver"
}

restore_pricing_snapshot() {
  (
    cd "$REPO_ROOT"
    go run ./internal/pricing/cmd/litellm-snapshot -restore
  )
}

install_frontend_deps() {
  npm ci
}

main() {
  local target_triple go_target goos goarch ext host_triple
  target_triple="$(resolve_target_triple)"
  if [ -z "$target_triple" ]; then
    echo "error: target triple is empty" >&2
    exit 1
  fi
  go_target="$(map_go_target "$target_triple")"
  read -r goos goarch <<<"$go_target"
  host_triple="$(detect_host_triple)"

  echo "Building agentsview backend for sidecar ($target_triple -> $goos/$goarch)..."
  if [ "$target_triple" != "$host_triple" ]; then
    echo "warning: cross-target sidecar build requested from host $host_triple" >&2
  fi

  (
    cd "$REPO_ROOT/frontend"
    install_frontend_deps
    npm run build
  )

  rm -rf "$REPO_ROOT/internal/web/dist"
  cp -r "$REPO_ROOT/frontend/dist" "$REPO_ROOT/internal/web/dist"

  ext=""
  if [[ "$target_triple" == *"windows"* ]]; then
    ext=".exe"
  fi

  local version commit build_date ldflags tmp_dir build_bin
  version="$(resolve_version)"
  patch_tauri_version "$version"
  commit="$(git -C "$REPO_ROOT" rev-parse --short HEAD 2>/dev/null || echo "unknown")"
  build_date="$(date -u +"%Y-%m-%dT%H:%M:%SZ")"
  ldflags="-X main.version=$version -X main.commit=$commit -X main.buildDate=$build_date -s -w"

  tmp_dir="$(mktemp -d)"
  trap 'rm -rf "${tmp_dir:-}"' EXIT
  build_bin="$tmp_dir/agentsview$ext"
  restore_pricing_snapshot

  (
    cd "$REPO_ROOT"
    CGO_ENABLED=1 GOOS="$goos" GOARCH="$goarch" \
      go build -tags fts5 -ldflags "$ldflags" -trimpath \
      -o "$build_bin" ./cmd/agentsview
  )

  if [ ! -f "$build_bin" ]; then
    echo "error: built backend binary not found at $build_bin" >&2
    exit 1
  fi

  local out_dir out_bin
  out_dir="$TAURI_DIR/src-tauri/binaries"
  out_bin="$out_dir/agentsview-$target_triple$ext"

  mkdir -p "$out_dir"
  cp "$build_bin" "$out_bin"
  chmod +x "$out_bin" || true

  echo "Prepared sidecar binary: $out_bin"
}

if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
  main "$@"
fi