#!/usr/bin/env bash

# SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0

set -e

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
TARGET_DIR="${CARGO_TARGET_DIR:-$PROJECT_ROOT/target}"
BINARY="$TARGET_DIR/debug/openshell"
STATE_FILE="$PROJECT_ROOT/.cache/openshell-build.state"
CALLER_PWD="$PWD"

# ---------------------------------------------------------------------------
# Fingerprint-based rebuild check
#
# Collect dirty files from git, filter to paths in the openshell-cli dependency
# closure, hash their contents, and compare against a persisted state file. We
# also track HEAD so that branch switches / pulls are detected.
# ---------------------------------------------------------------------------

needs_build=0

if [[ ! -x "$BINARY" ]]; then
  needs_build=1
else
  cd "$PROJECT_ROOT"

  # Current HEAD commit (detects branch switches, pulls, rebases)
  current_head=$(git rev-parse HEAD 2>/dev/null || echo "unknown")

  # Collect dirty (modified, staged, untracked) files
  changed_files=()
  while IFS= read -r path; do
    changed_files+=("$path")
  done < <(
    {
      git diff --name-only 2>/dev/null
      git diff --name-only --cached 2>/dev/null
      git ls-files --others --exclude-standard 2>/dev/null
    } | sort -u
  )

  # Filter to paths that can affect the openshell-cli binary
  matches_cli() {
    local path=$1
    case "$path" in
      Cargo.toml|Cargo.lock|proto/*)
        return 0 ;;
      crates/openshell-cli/*|crates/openshell-core/*|crates/openshell-bootstrap/*)
        return 0 ;;
      crates/openshell-prover/*)
        return 0 ;;
      crates/openshell-policy/*|crates/openshell-providers/*|crates/openshell-tui/*)
        return 0 ;;
      *)
        return 1 ;;
    esac
  }

  # Compute a composite fingerprint of matching dirty files
  payload=""
  for path in "${changed_files[@]}"; do
    matches_cli "$path" || continue
    if [[ -e "$path" ]]; then
      digest=$(shasum -a 256 "$path" | cut -d ' ' -f 1)
    else
      digest="__MISSING__"
    fi
    payload+="${path}:${digest}"$'\n'
  done

  if [[ -n "$payload" ]]; then
    current_fingerprint=$(printf '%s' "$payload" | shasum -a 256 | cut -d ' ' -f 1)
  else
    current_fingerprint=""
  fi

  # Load previous state
  previous_head=""
  previous_fingerprint=""
  if [[ -f "$STATE_FILE" ]]; then
    while IFS='=' read -r key value; do
      case "$key" in
        head) previous_head=$value ;;
        fingerprint) previous_fingerprint=$value ;;
      esac
    done < "$STATE_FILE"
  fi

  # Decide whether to rebuild
  if [[ "$current_head" != "$previous_head" ]]; then
    needs_build=1
  elif [[ "$current_fingerprint" != "$previous_fingerprint" ]]; then
    needs_build=1
  fi
fi

if [[ "$needs_build" == "1" ]]; then
  echo "Recompiling openshell..." >&2
  build_args=(--package openshell-cli --quiet)
  if ! command -v pkg-config >/dev/null 2>&1 || ! pkg-config --exists z3 >/dev/null 2>&1; then
    z3_prefix=""
    if command -v brew >/dev/null 2>&1; then
      z3_prefix=$(brew --prefix z3 2>/dev/null || true)
    fi

    for candidate in "$z3_prefix" /opt/homebrew/opt/z3 /usr/local/opt/z3; do
      if [[ -n "$candidate" && -f "$candidate/include/z3.h" && -d "$candidate/lib" ]]; then
        echo "Using local Z3 from ${candidate} for CLI build." >&2
        export Z3_SYS_Z3_HEADER="${candidate}/include/z3.h"
        export Z3_LIBRARY_PATH_OVERRIDE="${candidate}/lib"
        break
      fi
    done
  fi
  cargo build "${build_args[@]}"
  # Persist state after successful build
  mkdir -p "$(dirname "$STATE_FILE")"
  cd "$PROJECT_ROOT"
  new_head=$(git rev-parse HEAD 2>/dev/null || echo "unknown")
  # Recompute fingerprint of remaining dirty files (build may not change them)
  post_files=()
  while IFS= read -r path; do
    post_files+=("$path")
  done < <(
    {
      git diff --name-only 2>/dev/null
      git diff --name-only --cached 2>/dev/null
      git ls-files --others --exclude-standard 2>/dev/null
    } | sort -u
  )

  matches_cli() {
    local path=$1
    case "$path" in
      Cargo.toml|Cargo.lock|proto/*)
        return 0 ;;
      crates/openshell-cli/*|crates/openshell-core/*|crates/openshell-bootstrap/*)
        return 0 ;;
      crates/openshell-prover/*)
        return 0 ;;
      crates/openshell-policy/*|crates/openshell-providers/*|crates/openshell-tui/*)
        return 0 ;;
      *)
        return 1 ;;
    esac
  }

  post_payload=""
  for path in "${post_files[@]}"; do
    matches_cli "$path" || continue
    if [[ -e "$path" ]]; then
      digest=$(shasum -a 256 "$path" | cut -d ' ' -f 1)
    else
      digest="__MISSING__"
    fi
    post_payload+="${path}:${digest}"$'\n'
  done

  if [[ -n "$post_payload" ]]; then
    new_fingerprint=$(printf '%s' "$post_payload" | shasum -a 256 | cut -d ' ' -f 1)
  else
    new_fingerprint=""
  fi

  cat > "$STATE_FILE" <<EOF
head=${new_head}
fingerprint=${new_fingerprint}
EOF
fi

cd "$CALLER_PWD"
exec "$BINARY" "$@"