grep.c

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#include <ascii-chat/log/grep.h>
#include <ascii-chat/common.h>
#include <ascii-chat/log/log.h>
#include <ascii-chat/util/lifecycle.h>
#include <ascii-chat/util/pcre2.h>
#include <ascii-chat/util/utf8.h>
#include <ascii-chat/video/terminal/ansi.h>
#include <ascii-chat/platform/terminal.h>
#include <ascii-chat/platform/thread.h>
#include <ascii-chat/log/search.h>
 
#include <string.h>
#include <stdint.h>
 
#ifdef _WIN32
#include <windows.h>
#else
#include <sched.h>
#endif
 
#define HIGHLIGHT_DARK_BG 70   // Dark grey for dark theme backgrounds
#define HIGHLIGHT_LIGHT_BG 200 // Light grey for light theme backgrounds
 
#define MIN_HIGHLIGHT_DISTANCE 40
 
static inline float calculate_luminance(uint8_t r, uint8_t g, uint8_t b) {
  return (0.2126f * r + 0.7152f * g + 0.0722f * b) / 255.0f;
}
 
typedef struct {
  const char *original;         
  char *parsed_pattern;         
  pcre2_singleton_t *singleton; 
  bool is_fixed_string;         
  bool case_insensitive;        
  bool invert;                  
  bool global_flag;             
  int context_before;           
  int context_after;            
} grep_pattern_t;
 
static struct {
  grep_pattern_t *patterns;         
  int pattern_count;                
  int pattern_capacity;             
  bool enabled;                     
  tls_key_t match_data_key;         
  lifecycle_t match_data_lifecycle; 
 
  // Context line buffering
  char **line_buffer;    
  int buffer_size;       
  int buffer_pos;        
  int lines_after_match; 
  int max_context_after; 
 
  // Save/restore for interactive grep
  grep_pattern_t *saved_patterns; 
  int saved_pattern_count;        
  int saved_pattern_capacity;     
  bool saved_enabled;             
 
  // Cached highlight color (avoid querying terminal every render)
  uint8_t cached_highlight_r, cached_highlight_g, cached_highlight_b;
  uint64_t last_color_query_us;
} g_filter_state = {
    .patterns = NULL,
    .pattern_count = 0,
    .pattern_capacity = 0,
    .enabled = false,
    .match_data_lifecycle = LIFECYCLE_INIT,
    .line_buffer = NULL,
    .buffer_size = 0,
    .buffer_pos = 0,
    .lines_after_match = 0,
    .max_context_after = 0,
    .saved_patterns = NULL,
    .saved_pattern_count = 0,
    .saved_pattern_capacity = 0,
    .saved_enabled = false,
    .cached_highlight_r = 70,
    .cached_highlight_g = 70,
    .cached_highlight_b = 70,
    .last_color_query_us = 0,
};
 
static void destroy_match_data(void *data) {
  if (data) {
    pcre2_match_data_free((pcre2_match_data *)data);
  }
}
 
static void create_match_data_key(void) {
  ascii_tls_key_create(&g_filter_state.match_data_key, destroy_match_data);
}
 
static void get_highlight_color(uint8_t *r, uint8_t *g, uint8_t *b) {
  // Get current time for cache validation
  uint64_t now_us = platform_get_monotonic_time_us();
  uint64_t cache_age_us = now_us - g_filter_state.last_color_query_us;
 
  // Use cached color if recent (refresh every 2 seconds)
  if (cache_age_us < 2 * US_PER_SEC_INT) {
    *r = g_filter_state.cached_highlight_r;
    *g = g_filter_state.cached_highlight_g;
    *b = g_filter_state.cached_highlight_b;
    return;
  }
 
  // Query terminal color (only every 2 seconds)
  // Note: Skip querying during interactive grep mode to avoid PTY state issues
  // that can cause spurious ESC bytes in stdin
  uint8_t bg_r = 0, bg_g = 0, bg_b = 0;
  bool has_bg_color = log_search_is_active() ? false : terminal_query_background_color(&bg_r, &bg_g, &bg_b);
 
  bool is_dark;
  if (has_bg_color) {
    // Calculate luminance from actual background color
    float luminance = calculate_luminance(bg_r, bg_g, bg_b);
    is_dark = (luminance < 0.5f); // Dark if luminance < 50%
  } else {
    // Fall back to heuristic detection
    is_dark = terminal_has_dark_background();
  }
 
  // Choose highlight: dark bg = dark highlight, light bg = light highlight
  uint8_t grey = is_dark ? HIGHLIGHT_DARK_BG : HIGHLIGHT_LIGHT_BG;
 
  // If we have the actual background color, check if it's too close to our grey
  if (has_bg_color) {
    uint8_t bg_grey = (uint8_t)((bg_r + bg_g + bg_b) / 3);
    int distance = abs((int)bg_grey - (int)grey);
 
    // If background is too close to our grey, use black/white for maximum contrast
    if (distance < MIN_HIGHLIGHT_DISTANCE) {
      grey = is_dark ? 0 : 255; // Black for dark terminals, white for light
    }
  }
 
  // Cache the result
  g_filter_state.cached_highlight_r = grey;
  g_filter_state.cached_highlight_g = grey;
  g_filter_state.cached_highlight_b = grey;
  g_filter_state.last_color_query_us = now_us;
 
  *r = grey;
  *g = grey;
  *b = grey;
}
 
static size_t map_plain_to_colored_pos(const char *colored_text, size_t char_pos) {
  size_t byte_pos = 0;
  size_t chars_seen = 0;
 
  while (colored_text[byte_pos] != '\0' && chars_seen < char_pos) {
    // Check for ANSI escape sequence (handle all escape types, not just CSI)
    if (colored_text[byte_pos] == '\x1b') {
      byte_pos++;
      // Check if there's a next byte before reading it
      if (colored_text[byte_pos] == '\0') {
        // Incomplete escape sequence at end of string, just break
        break;
      }
      unsigned char next = (unsigned char)colored_text[byte_pos];
      if (next == '[') {
        // CSI sequence: \x1b[...final_byte (where final byte is 0x40-0x7E)
        byte_pos++;
        while (colored_text[byte_pos] != '\0') {
          unsigned char c = (unsigned char)colored_text[byte_pos];
          byte_pos++;
          // Final byte ends the sequence (0x40-0x7E)
          if (c >= 0x40 && c <= 0x7E) {
            break;
          }
        }
      } else if (next >= 0x40 && next <= 0x7E) {
        // 2-byte Fe sequence: \x1b + final_byte (e.g., \x1b7, \x1b8)
        byte_pos++;
      } else if (next == '(' || next == ')' || next == '*' || next == '+') {
        // Designate character set sequences: \x1b( + charset (3 bytes total)
        byte_pos++; // skip designator
        if (colored_text[byte_pos] != '\0') {
          byte_pos++; // skip charset ID
        }
      } else {
        // Unknown escape sequence type, try to skip conservatively
        if (colored_text[byte_pos] != '\0') {
          byte_pos++;
        }
      }
    } else {
      // Regular character - decode UTF-8 to get byte length
      uint32_t codepoint;
      int utf8_len = utf8_decode((const uint8_t *)(colored_text + byte_pos), &codepoint);
      if (utf8_len < 0) {
        utf8_len = 1; // Invalid UTF-8, treat as single byte
      }
 
      // Advance by all bytes of this UTF-8 character
      byte_pos += utf8_len;
 
      // Only increment character count once per character (not per byte)
      chars_seen++;
    }
  }
 
  return byte_pos;
}
 
static void ensure_match_data_key_initialized(void) {
  if (!lifecycle_init_once(&g_filter_state.match_data_lifecycle)) {
    return; // Already initialized, spin-wait completed
  }
  // Winner of init_once - do the initialization work
  create_match_data_key();
  lifecycle_init_commit(&g_filter_state.match_data_lifecycle);
}
 
static pcre2_match_data *get_thread_match_data(void) {
  ensure_match_data_key_initialized();
 
  pcre2_match_data *data = ascii_tls_get(g_filter_state.match_data_key);
  if (!data) {
    // Find any regex pattern to create match data from
    for (int i = 0; i < g_filter_state.pattern_count; i++) {
      if (g_filter_state.patterns[i].singleton) {
        pcre2_code *code = asciichat_pcre2_singleton_get_code(g_filter_state.patterns[i].singleton);
        if (code) {
          data = pcre2_match_data_create_from_pattern(code, NULL);
          if (data) {
            ascii_tls_set(g_filter_state.match_data_key, data);
            break;
          }
        }
      }
    }
  }
 
  return data;
}
 
// Use the shared parse_result_t from filter.h
typedef grep_parse_result_t parse_result_t;
 
grep_parse_result_t grep_parse_pattern(const char *input) {
  parse_result_t result = {0};
  result.pcre2_options = PCRE2_UTF | PCRE2_UCP; // Default: UTF-8 mode
 
  if (!input || strlen(input) == 0) {
    return result; // Invalid: empty pattern
  }
 
  size_t len = strlen(input);
  const char *closing_slash = NULL;
  const char *pattern_start = input;
 
  // Check if pattern uses /pattern/flags format (explicit)
  if (input[0] == '/') {
    // Format 1: /pattern/flags
    if (len < 3) {
      return result; // Invalid: too short for /pattern/ format
    }
 
    // Find closing slash - don't treat backslash as an escape character
    // (backslashes are regex escapes, not delimiter escapes)
    closing_slash = strchr(input + 1, '/');
    if (!closing_slash) {
      return result; // Invalid: missing closing /
    }
 
    pattern_start = input + 1;
  } else {
    // Check for pattern/flags format (implicit, no leading slash)
    // Find the last forward slash to use as delimiter
    closing_slash = strrchr(input, '/');
 
    const char *implicit_flags = closing_slash ? closing_slash + 1 : NULL;
    bool implicit_flags_valid = closing_slash && closing_slash > input && *implicit_flags != '\0';
    if (implicit_flags_valid) {
      for (const char *flag = implicit_flags; *flag; flag++) {
        if (!strchr("imsxgIF", *flag) && *flag != 'A' && *flag != 'B' && *flag != 'C' &&
            !(*flag >= '0' && *flag <= '9')) {
          implicit_flags_valid = false;
          break;
        }
      }
    }
 
    if (implicit_flags_valid) {
      // There's at least one slash (not at the beginning)
      // Try to parse as pattern/flags format
      pattern_start = input;
    } else {
      // No slash or slash at beginning - treat as plain pattern
      closing_slash = NULL;
    }
  }
 
  if (closing_slash) {
    // Extract pattern between start and closing slash
    size_t pattern_len = (size_t)(closing_slash - pattern_start);
    if (pattern_len == 0) {
      return result; // Invalid: empty pattern
    }
    if (pattern_len >= sizeof(result.pattern)) {
      pattern_len = sizeof(result.pattern) - 1;
    }
    memcpy(result.pattern, pattern_start, pattern_len);
    result.pattern[pattern_len] = '\0';
 
    // Parse flags after closing slash
    // First pass: check for F flag
    const char *flags = closing_slash + 1;
    bool has_F_flag = (strchr(flags, 'F') != NULL);
 
    // Parse all flags
    for (const char *p = flags; *p; p++) {
      char c = *p;
 
      // Single-character flags
      if (c == 'i') {
        result.pcre2_options |= PCRE2_CASELESS;
        result.case_insensitive = true;
      } else if (c == 'm') {
        result.pcre2_options |= PCRE2_MULTILINE;
      } else if (c == 's') {
        result.pcre2_options |= PCRE2_DOTALL;
      } else if (c == 'x') {
        result.pcre2_options |= PCRE2_EXTENDED;
      } else if (c == 'g') {
        result.global_flag = true;
      } else if (c == 'I') {
        result.invert = true;
      } else if (c == 'F') {
        result.is_fixed_string = true;
      }
      // Multi-character flags with integers
      else if (c == 'A') {
        p++; // Move to digits
        int num = 0;
        while (*p >= '0' && *p <= '9') {
          num = num * 10 + (*p - '0');
          p++;
        }
        p--;                                        // Back up one (for loop will increment)
        result.context_after = (num > 0) ? num : 1; // Default to 1 if no number
      } else if (c == 'B') {
        p++;
        int num = 0;
        while (*p >= '0' && *p <= '9') {
          num = num * 10 + (*p - '0');
          p++;
        }
        p--;
        result.context_before = (num > 0) ? num : 1;
      } else if (c == 'C') {
        p++;
        int num = 0;
        while (*p >= '0' && *p <= '9') {
          num = num * 10 + (*p - '0');
          p++;
        }
        p--;
        int ctx = (num > 0) ? num : 1;
        result.context_before = ctx;
        result.context_after = ctx;
      } else {
        // Invalid flag character - only error if not using F flag
        if (!has_F_flag) {
          return result; // Invalid
        }
        // Otherwise ignore invalid flags (they're part of the fixed string context)
      }
    }
  } else {
    // Format 3: Plain pattern without slashes (treat as regex, no flags)
    size_t pattern_len = len;
    if (pattern_len >= sizeof(result.pattern)) {
      pattern_len = sizeof(result.pattern) - 1;
    }
    memcpy(result.pattern, input, pattern_len);
    result.pattern[pattern_len] = '\0';
 
    // No flags for plain format - just use default options
    // (PCRE2_UTF | PCRE2_UCP already set at the top)
  }
 
  result.valid = true;
  return result;
}
 
asciichat_error_t grep_init(const char *pattern) {
  // Reject NULL or empty patterns
  if (!pattern) {
    return SET_ERRNO(ERROR_INVALID_PARAM, "Pattern cannot be NULL");
  }
  if (strlen(pattern) == 0) {
    return SET_ERRNO(ERROR_INVALID_PARAM, "Pattern cannot be empty");
  }
 
  // Parse pattern
  parse_result_t parsed = grep_parse_pattern(pattern);
  if (!parsed.valid) {
    log_error("Invalid --grep pattern format: \"%s\"", pattern);
    log_error("Use /pattern/flags format (e.g., \"/query/ig\") or plain regex (e.g., \"query\")");
    return SET_ERRNO(ERROR_INVALID_PARAM, "Invalid --grep pattern format");
  }
 
  // Allocate or expand pattern array
  if (g_filter_state.pattern_count >= g_filter_state.pattern_capacity) {
    int new_capacity = (g_filter_state.pattern_capacity == 0) ? 4 : g_filter_state.pattern_capacity * 2;
    grep_pattern_t *new_patterns =
        SAFE_REALLOC(g_filter_state.patterns, new_capacity * sizeof(grep_pattern_t), grep_pattern_t *);
    if (!new_patterns) {
      return SET_ERRNO(ERROR_MEMORY, "Failed to allocate pattern array");
    }
    g_filter_state.patterns = new_patterns;
    g_filter_state.pattern_capacity = new_capacity;
  }
 
  // Add new pattern
  grep_pattern_t *new_pat = &g_filter_state.patterns[g_filter_state.pattern_count];
  memset(new_pat, 0, sizeof(*new_pat));
 
  // Make a copy of the original pattern string (argv pointers may be deallocated)
  char *original_copy = SAFE_MALLOC(strlen(pattern) + 1, char *);
  if (!original_copy) {
    return SET_ERRNO(ERROR_MEMORY, "Failed to allocate original pattern string");
  }
  memcpy(original_copy, pattern, strlen(pattern) + 1);
  new_pat->original = original_copy;
 
  new_pat->parsed_pattern = SAFE_MALLOC(strlen(parsed.pattern) + 1, char *);
  if (!new_pat->parsed_pattern) {
    SAFE_FREE(original_copy);
    return SET_ERRNO(ERROR_MEMORY, "Failed to allocate pattern string");
  }
  memcpy(new_pat->parsed_pattern, parsed.pattern, strlen(parsed.pattern) + 1);
 
  new_pat->is_fixed_string = parsed.is_fixed_string;
  new_pat->case_insensitive = parsed.case_insensitive;
  new_pat->invert = parsed.invert;
  new_pat->global_flag = parsed.global_flag;
  new_pat->context_before = parsed.context_before;
  new_pat->context_after = parsed.context_after;
 
  // Compile regex (skip for fixed strings)
  if (!parsed.is_fixed_string) {
    new_pat->singleton = asciichat_pcre2_singleton_compile(parsed.pattern, parsed.pcre2_options);
    if (!new_pat->singleton) {
      SAFE_FREE(new_pat->parsed_pattern);
      return SET_ERRNO(ERROR_INVALID_PARAM, "Failed to compile regex pattern");
    }
 
    // Validate compilation
    pcre2_code *code = asciichat_pcre2_singleton_get_code(new_pat->singleton);
    if (!code) {
      SAFE_FREE(new_pat->parsed_pattern);
      return SET_ERRNO(ERROR_INVALID_PARAM, "Regex compilation failed");
    }
  }
 
  g_filter_state.pattern_count++;
 
  // Update context buffer size if needed
  if (parsed.context_before > g_filter_state.buffer_size) {
    // Reallocate line buffer
    char **new_buffer = SAFE_REALLOC(g_filter_state.line_buffer, parsed.context_before * sizeof(char *), char **);
    if (!new_buffer) {
      return SET_ERRNO(ERROR_MEMORY, "Failed to allocate context line buffer");
    }
    // Initialize new slots
    for (int i = g_filter_state.buffer_size; i < parsed.context_before; i++) {
      new_buffer[i] = NULL;
    }
    g_filter_state.line_buffer = new_buffer;
    g_filter_state.buffer_size = parsed.context_before;
  }
 
  // Update max context_after
  if (parsed.context_after > g_filter_state.max_context_after) {
    g_filter_state.max_context_after = parsed.context_after;
  }
 
  g_filter_state.enabled = true;
  log_info("Added --grep pattern #%d: %s", g_filter_state.pattern_count, pattern);
 
  return ASCIICHAT_OK;
}
 
bool grep_should_output(const char *log_line, size_t *match_start, size_t *match_len) {
  // Reject NULL lines
  if (!log_line) {
    if (match_start)
      *match_start = 0;
    if (match_len)
      *match_len = 0;
    return false;
  }
 
  // If filtering disabled, output everything
  if (!g_filter_state.enabled) {
    return true;
  }
 
  // Check if we're in "context after" mode (outputting lines after a match)
  if (g_filter_state.lines_after_match > 0) {
    g_filter_state.lines_after_match--;
    *match_start = 0;
    *match_len = 0;
 
    // Store in buffer even during context-after mode
    if (g_filter_state.buffer_size > 0) {
      SAFE_FREE(g_filter_state.line_buffer[g_filter_state.buffer_pos]);
      size_t line_len = strlen(log_line) + 1;
      g_filter_state.line_buffer[g_filter_state.buffer_pos] = SAFE_MALLOC(line_len, char *);
      if (g_filter_state.line_buffer[g_filter_state.buffer_pos]) {
        memcpy(g_filter_state.line_buffer[g_filter_state.buffer_pos], log_line, line_len);
      }
      g_filter_state.buffer_pos = (g_filter_state.buffer_pos + 1) % g_filter_state.buffer_size;
    }
 
    return true; // Output context line
  }
 
  pcre2_match_data *match_data = get_thread_match_data();
  size_t line_len = strlen(log_line);
 
  // Try each pattern (OR logic)
  bool any_match = false;
  grep_pattern_t *matched_pattern = NULL;
 
  for (int i = 0; i < g_filter_state.pattern_count; i++) {
    grep_pattern_t *pat = &g_filter_state.patterns[i];
    bool this_match = false;
 
    if (pat->is_fixed_string) {
      // Fixed string matching (with optional case-insensitive support)
      const char *found;
      if (pat->case_insensitive) {
        // Unicode-aware case-insensitive search
        found = utf8_strcasestr(log_line, pat->parsed_pattern);
      } else {
        // Case-sensitive search
        found = strstr(log_line, pat->parsed_pattern);
      }
 
      if (found) {
        this_match = true;
        if (!matched_pattern) {
          *match_start = (size_t)(found - log_line);
          *match_len = strlen(pat->parsed_pattern);
          matched_pattern = pat;
        }
      }
    } else {
      // Regex matching
      if (!match_data || !pat->singleton) {
        continue;
      }
 
      pcre2_code *code = asciichat_pcre2_singleton_get_code(pat->singleton);
      if (!code) {
        continue;
      }
 
      int rc = pcre2_jit_match(code, (PCRE2_SPTR)log_line, line_len, 0, 0, match_data, NULL);
      if (rc >= 0) {
        this_match = true;
        if (!matched_pattern) {
          PCRE2_SIZE *ovector = pcre2_get_ovector_pointer(match_data);
          *match_start = (size_t)ovector[0];
          *match_len = (size_t)(ovector[1] - ovector[0]);
          matched_pattern = pat;
        }
      }
    }
 
    // Apply invert flag
    if (pat->invert) {
      this_match = !this_match;
    }
 
    if (this_match) {
      any_match = true;
      // Update matched_pattern if this one has more context
      if (!matched_pattern || (pat->context_before + pat->context_after) >
                                  (matched_pattern->context_before + matched_pattern->context_after)) {
        matched_pattern = pat;
      }
    }
  }
 
  // If any pattern matched
  if (any_match && matched_pattern) {
    // Output context_before lines from circular buffer
    if (matched_pattern->context_before > 0 && g_filter_state.buffer_size > 0) {
      int num_lines = (matched_pattern->context_before < g_filter_state.buffer_size) ? matched_pattern->context_before
                                                                                     : g_filter_state.buffer_size;
 
      // Calculate starting position in circular buffer
      int start_pos = (g_filter_state.buffer_pos - num_lines + g_filter_state.buffer_size) % g_filter_state.buffer_size;
 
      // Output buffered lines
      for (int i = 0; i < num_lines; i++) {
        int pos = (start_pos + i) % g_filter_state.buffer_size;
        if (g_filter_state.line_buffer[pos]) {
          fprintf(stderr, "%s\n", g_filter_state.line_buffer[pos]);
        }
      }
    }
 
    // Set up context_after counter
    if (matched_pattern->context_after > 0) {
      g_filter_state.lines_after_match = matched_pattern->context_after;
    }
 
    return true; // Match found, output line
  }
 
  // No match - store in context buffer for potential future use
  if (g_filter_state.buffer_size > 0) {
    SAFE_FREE(g_filter_state.line_buffer[g_filter_state.buffer_pos]);
    size_t line_len_copy = strlen(log_line) + 1;
    g_filter_state.line_buffer[g_filter_state.buffer_pos] = SAFE_MALLOC(line_len_copy, char *);
    if (g_filter_state.line_buffer[g_filter_state.buffer_pos]) {
      memcpy(g_filter_state.line_buffer[g_filter_state.buffer_pos], log_line, line_len_copy);
    }
    g_filter_state.buffer_pos = (g_filter_state.buffer_pos + 1) % g_filter_state.buffer_size;
  }
 
  return false; // No match, suppress line
}
 
char *grep_highlight_colored_copy(const char *colored_text, const char *plain_text, size_t match_start,
                                  size_t match_len) {
  const char *result = grep_highlight_colored(colored_text, plain_text, match_start, match_len);
  if (result) {
    size_t result_len = strlen(result) + 1;
    char *copy = SAFE_MALLOC(result_len, char *);
    if (copy) {
      memcpy(copy, result, result_len);
      return copy;
    }
  }
  return NULL;
}
 
const char *grep_highlight_colored(const char *colored_text, const char *plain_text, size_t match_start,
                                   size_t match_len) {
  static __thread char highlight_buffer[16384];
 
  if (!colored_text || !plain_text || match_len == 0) {
    return colored_text;
  }
 
  // When interactive grep is active, check if it has global flag
  bool is_log_search = log_search_is_active();
  bool should_use_global_pattern = false;
  grep_pattern_t *global_pat = NULL;
 
  if (!is_log_search) {
    // If any pattern has global flag, highlight ALL matches for that pattern
    // Find first pattern with global flag
    for (int i = 0; i < g_filter_state.pattern_count; i++) {
      if (g_filter_state.patterns[i].global_flag && !g_filter_state.patterns[i].is_fixed_string) {
        global_pat = &g_filter_state.patterns[i];
        should_use_global_pattern = true;
        break;
      }
    }
  } else if (log_search_get_global_highlight()) {
    // Interactive grep is active and has /g flag - do global matching on the provided pattern
    // We'll do all-match highlighting using the match position to extract the pattern
    // and re-match for all occurrences
    should_use_global_pattern = true;
    // global_pat stays NULL, but we set the flag to enable global matching below
  }
 
  if (should_use_global_pattern) {
    pcre2_code *code = NULL;
    pcre2_match_data *match_data = NULL;
    char fixed_string_pattern[256] = {0};
    bool is_fixed_string_pattern = false;
    bool case_insensitive_fixed = false;
 
    // Get code from CLI pattern or interactive grep pattern
    if (global_pat && global_pat->singleton) {
      code = asciichat_pcre2_singleton_get_code(global_pat->singleton);
      match_data = get_thread_match_data();
    } else if (is_log_search) {
      // Interactive grep global highlighting - get pattern from grep state
      void *grep_singleton_void = log_search_get_pattern_singleton();
      if (grep_singleton_void) {
        pcre2_singleton_t *grep_singleton = (pcre2_singleton_t *)grep_singleton_void;
        code = asciichat_pcre2_singleton_get_code(grep_singleton);
        // Create match data for this pattern
        if (code) {
          match_data = pcre2_match_data_create_from_pattern(code, NULL);
        }
      } else {
        // No regex pattern - check if it's a fixed string pattern in interactive grep
        int pattern_len = log_search_get_input_len();
        const char *pattern = log_search_get_input_buffer();
        if (pattern_len > 0 && pattern && pattern_len < (int)sizeof(fixed_string_pattern)) {
          SAFE_STRNCPY(fixed_string_pattern, pattern, sizeof(fixed_string_pattern) - 1);
          is_fixed_string_pattern = true;
          case_insensitive_fixed = log_search_get_case_insensitive();
        }
      }
    }
 
    if (!code && !is_fixed_string_pattern) {
      if (match_data && is_log_search) {
        pcre2_match_data_free(match_data); // Free if we created it
      }
      return colored_text; // Fall back to no highlighting
    }
 
    size_t plain_len = strlen(plain_text);
    size_t colored_len = strlen(colored_text);
    char *dst = highlight_buffer;
    size_t plain_offset = 0;
    size_t colored_pos = 0;
 
    // Handle fixed string global matching
    if (is_fixed_string_pattern) {
      while (plain_offset < plain_len) {
        // Find next occurrence of fixed string
        const char *found = NULL;
        if (case_insensitive_fixed) {
          found = utf8_strcasestr(plain_text + plain_offset, fixed_string_pattern);
        } else {
          found = strstr(plain_text + plain_offset, fixed_string_pattern);
        }
 
        if (!found) {
          break; // No more matches
        }
 
        size_t plain_match_start = (size_t)(found - plain_text);
        size_t plain_match_end = plain_match_start + strlen(fixed_string_pattern);
 
        // Map to colored text positions (same as single-match path)
        size_t colored_match_start = map_plain_to_colored_pos(colored_text, plain_match_start);
        size_t colored_match_end = map_plain_to_colored_pos(colored_text, plain_match_end);
 
        // Copy text before match
        if (colored_match_start > colored_pos) {
          memcpy(dst, colored_text + colored_pos, colored_match_start - colored_pos);
          dst += (colored_match_start - colored_pos);
        }
 
        // Add highlight background
        uint8_t r, g, b;
        get_highlight_color(&r, &g, &b);
        dst = append_truecolor_bg(dst, r, g, b);
 
        // Copy matched text with background
        size_t match_byte_len = colored_match_end - colored_match_start;
        memcpy(dst, colored_text + colored_match_start, match_byte_len);
        dst += match_byte_len;
 
        // Reset background
        memcpy(dst, "\x1b[49m", 5);
        dst += 5;
 
        colored_pos = colored_match_end;
        plain_offset = plain_match_end;
      }
 
      // Copy remaining text
      if (colored_pos < colored_len) {
        memcpy(dst, colored_text + colored_pos, colored_len - colored_pos);
        dst += (colored_len - colored_pos);
      }
 
      // Reset both background and foreground at end
      *dst = '\0';
      return highlight_buffer;
    }
 
    // Find all matches in plain text and highlight in colored text (regex matching)
    while (plain_offset < plain_len) {
      int rc = pcre2_jit_match(code, (PCRE2_SPTR)plain_text, plain_len, plain_offset, 0, match_data, NULL);
      if (rc < 0) {
        break; // No more matches
      }
 
      PCRE2_SIZE *ovector = pcre2_get_ovector_pointer(match_data);
      size_t plain_match_start = (size_t)ovector[0];
      size_t plain_match_end = (size_t)ovector[1];
 
      // Map to colored text positions
      size_t colored_match_start = map_plain_to_colored_pos(colored_text, plain_match_start);
      size_t colored_match_end = map_plain_to_colored_pos(colored_text, plain_match_end);
 
      // Copy text before match
      if (colored_match_start > colored_pos) {
        memcpy(dst, colored_text + colored_pos, colored_match_start - colored_pos);
        dst += (colored_match_start - colored_pos);
      }
 
      // Add highlight background
      uint8_t r, g, b;
      get_highlight_color(&r, &g, &b);
      dst = append_truecolor_bg(dst, r, g, b);
 
      // Copy matched text, re-applying background after any [0m or [00m reset codes
      size_t match_byte_len = colored_match_end - colored_match_start;
      const char *match_src = colored_text + colored_match_start;
      char *dst_end = highlight_buffer + sizeof(highlight_buffer) - 1; // Absolute buffer end
      size_t i = 0;
      while (i < match_byte_len) {
        // Check for [0m or [00m reset codes
        if (i + 4 <= match_byte_len && match_src[i] == '\x1b' && match_src[i + 1] == '[' && match_src[i + 2] == '0' &&
            match_src[i + 3] == 'm') {
          // Found [0m - copy it and re-apply background (if room)
          if (dst + 4 >= dst_end)
            break;                 // Not enough space for the reset code itself
          *dst++ = match_src[i++]; // ESC
          *dst++ = match_src[i++]; // '['
          *dst++ = match_src[i++]; // '0'
          *dst++ = match_src[i++]; // 'm'
          // Re-apply highlight background after reset (only if room)
          if (dst + 20 < dst_end) {
            uint8_t r2, g2, b2;
            get_highlight_color(&r2, &g2, &b2);
            dst = append_truecolor_bg(dst, r2, g2, b2);
          }
        } else if (i + 5 <= match_byte_len && match_src[i] == '\x1b' && match_src[i + 1] == '[' &&
                   match_src[i + 2] == '0' && match_src[i + 3] == '0' && match_src[i + 4] == 'm') {
          // Found [00m - copy it and re-apply background (if room)
          if (dst + 5 >= dst_end)
            break;                 // Not enough space for the reset code itself
          *dst++ = match_src[i++]; // ESC
          *dst++ = match_src[i++]; // '['
          *dst++ = match_src[i++]; // '0'
          *dst++ = match_src[i++]; // '0'
          *dst++ = match_src[i++]; // 'm'
          // Re-apply highlight background after reset (only if room)
          if (dst + 20 < dst_end) {
            uint8_t r2, g2, b2;
            get_highlight_color(&r2, &g2, &b2);
            dst = append_truecolor_bg(dst, r2, g2, b2);
          }
        } else {
          // Regular character - just copy
          if (dst + 1 >= dst_end)
            break;
          *dst++ = match_src[i++];
        }
      }
 
      // Reset background only
      memcpy(dst, "\x1b[49m", 5);
      dst += 5;
 
      colored_pos = colored_match_end;
      plain_offset = plain_match_end;
 
      // Prevent infinite loop on zero-length matches
      if (plain_match_end == plain_match_start) {
        plain_offset++;
      }
    }
 
    // Copy remaining text
    if (colored_pos < colored_len) {
      memcpy(dst, colored_text + colored_pos, colored_len - colored_pos);
      dst += (colored_len - colored_pos);
    }
 
    // Reset both background and foreground at end to prevent color bleeding
    *dst = '\0';
 
    // Clean up match data if we created it for interactive grep
    if (is_log_search && match_data && !global_pat) {
      pcre2_match_data_free(match_data);
    }
 
    return highlight_buffer;
  }
 
  // Single match highlighting (same logic as global path)
  // map_plain_to_colored_pos(N) returns byte position after counting N characters
  size_t colored_start = map_plain_to_colored_pos(colored_text, match_start);
  size_t colored_end = map_plain_to_colored_pos(colored_text, match_start + match_len);
 
  size_t colored_len = strlen(colored_text);
  char *dst = highlight_buffer;
 
  // Copy everything before the match
  if (colored_start > 0) {
    memcpy(dst, colored_text, colored_start);
    dst += colored_start;
  }
 
  // Add highlight background
  uint8_t r, g, b;
  get_highlight_color(&r, &g, &b);
  dst = append_truecolor_bg(dst, r, g, b);
 
  // Copy matched text, re-applying background after any [0m or [00m reset codes
  size_t match_byte_len = colored_end - colored_start;
  const char *match_src = colored_text + colored_start;
  char *dst_end = highlight_buffer + sizeof(highlight_buffer) - 1; // Absolute buffer end
  size_t i = 0;
 
  while (i < match_byte_len) {
    // Check for [0m or [00m reset codes
    if (i + 4 <= match_byte_len && match_src[i] == '\x1b' && match_src[i + 1] == '[' && match_src[i + 2] == '0' &&
        match_src[i + 3] == 'm') {
      // Found [0m - copy it and re-apply background (if room)
      if (dst + 4 >= dst_end)
        break;                 // Not enough space for even the reset code
      *dst++ = match_src[i++]; // ESC
      *dst++ = match_src[i++]; // '['
      *dst++ = match_src[i++]; // '0'
      *dst++ = match_src[i++]; // 'm'
      // Re-apply highlight background after reset (only if room)
      if (dst + 20 < dst_end) {
        uint8_t r2, g2, b2;
        get_highlight_color(&r2, &g2, &b2);
        dst = append_truecolor_bg(dst, r2, g2, b2);
      }
    } else if (i + 5 <= match_byte_len && match_src[i] == '\x1b' && match_src[i + 1] == '[' &&
               match_src[i + 2] == '0' && match_src[i + 3] == '0' && match_src[i + 4] == 'm') {
      // Found [00m - copy it and re-apply background (if room)
      if (dst + 5 >= dst_end)
        break;                 // Not enough space for even the reset code
      *dst++ = match_src[i++]; // ESC
      *dst++ = match_src[i++]; // '['
      *dst++ = match_src[i++]; // '0'
      *dst++ = match_src[i++]; // '0'
      *dst++ = match_src[i++]; // 'm'
      // Re-apply highlight background after reset (only if room)
      if (dst + 20 < dst_end) {
        uint8_t r3, g3, b3;
        get_highlight_color(&r3, &g3, &b3);
        dst = append_truecolor_bg(dst, r3, g3, b3);
      }
    } else {
      // Regular character - just copy
      if (dst + 1 >= dst_end) {
        break;
      }
      *dst++ = match_src[i++];
    }
  }
 
  // Reset only the background color to preserve foreground colors from headers
  // Using \x1b[49m (reset background only) instead of \x1b[0m (reset all)
  memcpy(dst, "\x1b[49m", 5);
  dst += 5;
 
  // Copy remaining text
  size_t remaining = colored_len - colored_end;
  if (remaining > 0) {
    memcpy(dst, colored_text + colored_end, remaining);
    dst += remaining;
  }
 
  *dst = '\0';
  return highlight_buffer;
}
 
const char *grep_highlight(const char *log_line, size_t match_start, size_t match_len) {
  static __thread char highlight_buffer[16384];
 
  if (!log_line || match_len == 0) {
    return log_line; // No highlighting needed
  }
 
  size_t line_len = strlen(log_line);
  if (match_start + match_len > line_len) {
    return log_line; // Invalid range
  }
 
  char *dst = highlight_buffer;
  const char *src = log_line;
  size_t pos = 0;
 
  // If any pattern has global flag, highlight ALL matches
  grep_pattern_t *global_pat = NULL;
  for (int i = 0; i < g_filter_state.pattern_count; i++) {
    if (g_filter_state.patterns[i].global_flag && !g_filter_state.patterns[i].is_fixed_string) {
      global_pat = &g_filter_state.patterns[i];
      break;
    }
  }
 
  if (global_pat && global_pat->singleton) {
    pcre2_code *code = asciichat_pcre2_singleton_get_code(global_pat->singleton);
    pcre2_match_data *match_data = get_thread_match_data();
 
    if (!code || !match_data) {
      return log_line; // Fall back to no highlighting
    }
 
    // Find all matches in the line
    size_t offset = 0;
    while (offset < line_len) {
      int rc = pcre2_jit_match(code, (PCRE2_SPTR)log_line, line_len, offset, 0, match_data, NULL);
      if (rc < 0) {
        break; // No more matches
      }
 
      PCRE2_SIZE *ovector = pcre2_get_ovector_pointer(match_data);
      size_t match_pos = (size_t)ovector[0];
      size_t match_end = (size_t)ovector[1];
      size_t len = match_end - match_pos;
 
      // Copy text before match
      if (match_pos > pos) {
        memcpy(dst, src + pos, match_pos - pos);
        dst += (match_pos - pos);
      }
 
      // Highlight the match (background only, preserve foreground color)
      uint8_t r, g, b;
      get_highlight_color(&r, &g, &b);
      dst = append_truecolor_bg(dst, r, g, b);
      memcpy(dst, src + match_pos, len);
      dst += len;
 
      pos = match_end;
      offset = match_end;
 
      // Prevent infinite loop on zero-length matches
      if (len == 0) {
        offset++;
      }
    }
 
    // Copy remaining text after last match
    if (pos < line_len) {
      memcpy(dst, src + pos, line_len - pos);
      dst += (line_len - pos);
    }
 
  } else {
    // Single match highlighting (original behavior)
    // Copy text before match
    if (match_start > 0) {
      memcpy(dst, log_line, match_start);
      dst += match_start;
    }
 
    // Add background color for match (preserve foreground color)
    uint8_t r, g, b;
    get_highlight_color(&r, &g, &b);
    dst = append_truecolor_bg(dst, r, g, b);
 
    // Copy matched text
    memcpy(dst, log_line + match_start, match_len);
    dst += match_len;
 
    // Copy text after match
    size_t remaining = line_len - (match_start + match_len);
    if (remaining > 0) {
      memcpy(dst, log_line + match_start + match_len, remaining);
      dst += remaining;
    }
  }
 
  *dst = '\0';
  return highlight_buffer;
}
 
void grep_destroy(void) {
  // Free all patterns
  for (int i = 0; i < g_filter_state.pattern_count; i++) {
    grep_pattern_t *pat = &g_filter_state.patterns[i];
    // Free the copied original string (need temp variable due to const qualifier)
    char *original_to_free = (char *)pat->original;
    SAFE_FREE(original_to_free);
    SAFE_FREE(pat->parsed_pattern);
    // Singletons are auto-cleaned by asciichat_pcre2_cleanup_all()
    pat->singleton = NULL;
  }
  SAFE_FREE(g_filter_state.patterns);
  g_filter_state.patterns = NULL; // Make idempotent
 
  // Free context buffer
  if (g_filter_state.line_buffer) {
    for (int i = 0; i < g_filter_state.buffer_size; i++) {
      SAFE_FREE(g_filter_state.line_buffer[i]);
    }
    SAFE_FREE(g_filter_state.line_buffer);
    g_filter_state.line_buffer = NULL; // Make idempotent
  }
 
  g_filter_state.pattern_count = 0;
  g_filter_state.pattern_capacity = 0;
  g_filter_state.buffer_size = 0;
  g_filter_state.buffer_pos = 0;
  g_filter_state.lines_after_match = 0;
  g_filter_state.max_context_after = 0;
  g_filter_state.enabled = false;
 
  // Note: Thread-local match_data is cleaned up via pthread_key destructor
}
 
/* ============================================================================
 * Save/Restore Functions for Interactive Grep
 * ========================================================================== */
 
asciichat_error_t grep_save_patterns(void) {
  // Free previous saved patterns if any
  if (g_filter_state.saved_patterns) {
    for (int i = 0; i < g_filter_state.saved_pattern_count; i++) {
      SAFE_FREE(g_filter_state.saved_patterns[i].parsed_pattern);
    }
    SAFE_FREE(g_filter_state.saved_patterns);
  }
 
  // Allocate saved pattern array
  if (g_filter_state.pattern_count > 0) {
    g_filter_state.saved_patterns =
        SAFE_MALLOC(g_filter_state.pattern_count * sizeof(grep_pattern_t), grep_pattern_t *);
    if (!g_filter_state.saved_patterns) {
      return SET_ERRNO(ERROR_MEMORY, "Failed to allocate saved pattern array");
    }
 
    // Deep copy all patterns
    for (int i = 0; i < g_filter_state.pattern_count; i++) {
      grep_pattern_t *src = &g_filter_state.patterns[i];
      grep_pattern_t *dst = &g_filter_state.saved_patterns[i];
 
      // Copy pattern structure
      *dst = *src;
 
      // Deep copy parsed_pattern string
      dst->parsed_pattern = SAFE_MALLOC(strlen(src->parsed_pattern) + 1, char *);
      if (!dst->parsed_pattern) {
        // Clean up partial save
        for (int j = 0; j < i; j++) {
          SAFE_FREE(g_filter_state.saved_patterns[j].parsed_pattern);
        }
        SAFE_FREE(g_filter_state.saved_patterns);
        g_filter_state.saved_patterns = NULL;
        return SET_ERRNO(ERROR_MEMORY, "Failed to save pattern string");
      }
      memcpy(dst->parsed_pattern, src->parsed_pattern, strlen(src->parsed_pattern) + 1);
 
      // Singleton pointers are shared (reference counted)
      dst->singleton = src->singleton;
    }
  }
 
  g_filter_state.saved_pattern_count = g_filter_state.pattern_count;
  g_filter_state.saved_pattern_capacity = g_filter_state.pattern_count;
  g_filter_state.saved_enabled = g_filter_state.enabled;
 
  return ASCIICHAT_OK;
}
 
asciichat_error_t grep_restore_patterns(void) {
  // Clear current patterns (but don't free the array)
  for (int i = 0; i < g_filter_state.pattern_count; i++) {
    SAFE_FREE(g_filter_state.patterns[i].parsed_pattern);
    g_filter_state.patterns[i].singleton = NULL;
  }
 
  // Ensure we have capacity for saved patterns
  if (g_filter_state.saved_pattern_count > g_filter_state.pattern_capacity) {
    grep_pattern_t *new_patterns = SAFE_REALLOC(
        g_filter_state.patterns, g_filter_state.saved_pattern_count * sizeof(grep_pattern_t), grep_pattern_t *);
    if (!new_patterns) {
      return SET_ERRNO(ERROR_MEMORY, "Failed to allocate pattern array for restore");
    }
    g_filter_state.patterns = new_patterns;
    g_filter_state.pattern_capacity = g_filter_state.saved_pattern_count;
  }
 
  // Restore patterns
  if (g_filter_state.saved_patterns) {
    for (int i = 0; i < g_filter_state.saved_pattern_count; i++) {
      grep_pattern_t *src = &g_filter_state.saved_patterns[i];
      grep_pattern_t *dst = &g_filter_state.patterns[i];
 
      // Copy pattern structure
      *dst = *src;
 
      // Deep copy parsed_pattern string
      dst->parsed_pattern = SAFE_MALLOC(strlen(src->parsed_pattern) + 1, char *);
      if (!dst->parsed_pattern) {
        // Clean up partial restore
        for (int j = 0; j < i; j++) {
          SAFE_FREE(g_filter_state.patterns[j].parsed_pattern);
        }
        g_filter_state.pattern_count = 0;
        return SET_ERRNO(ERROR_MEMORY, "Failed to restore pattern string");
      }
      memcpy(dst->parsed_pattern, src->parsed_pattern, strlen(src->parsed_pattern) + 1);
 
      // Singleton pointers are shared (reference counted)
      dst->singleton = src->singleton;
    }
  }
 
  g_filter_state.pattern_count = g_filter_state.saved_pattern_count;
  g_filter_state.enabled = g_filter_state.saved_enabled;
 
  return ASCIICHAT_OK;
}
 
void grep_clear_patterns(void) {
  // Don't free patterns, just set count to 0
  // This allows quick restore without reallocation
  g_filter_state.pattern_count = 0;
  g_filter_state.enabled = false;
}
 
int grep_get_pattern_count(void) {
  return g_filter_state.pattern_count;
}
 
const char *grep_get_last_pattern(void) {
  if (g_filter_state.pattern_count == 0) {
    return NULL;
  }
 
  // Return the original pattern string of the last pattern
  return g_filter_state.patterns[g_filter_state.pattern_count - 1].original;
}