/**
 * fgla.c - Find Glass utility for searching optical glass database
 *
 * Copyright (C) 2025 https://optics-design.com
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * See the COPYING file for the full license text.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include "glass_data.h"
#include "glamacdef.h"

// Security constants
#define MAX_SEARCH_TERM_LEN 256
#define MAX_GLASS_NAME_LEN 256
#define MAX_CATALOG_COUNT 10
#define MAX_NORMALIZED_LEN 512
#define GLASS_CODE_LEN 6

// Output format types
typedef enum {
    OUTPUT_CSV = 0,
    OUTPUT_TABLE = 1,
    OUTPUT_JSON = 2
} OutputFormat;

// Function to safely convert string to lowercase with length limit
void to_lowercase_safe(char* str, size_t max_len) {
    if (!str) return;
    
    for (size_t i = 0; i < max_len && str[i]; i++) {
        str[i] = tolower(str[i]);
    }
}

// Function to safely normalize string by removing dashes and converting to lowercase
int normalize_string_safe(const char* input, char* output, size_t output_size) {
    if (!input || !output || output_size < 2) return -1;
    
    size_t input_len = strnlen(input, MAX_GLASS_NAME_LEN);
    size_t j = 0;
    
    for (size_t i = 0; i < input_len && j < output_size - 1; i++) {
        if (input[i] != '-') {  // Skip dashes
            output[j++] = tolower(input[i]);
        }
    }
    output[j] = '\0';
    return 0;
}

// Function to safely check if needle is found in haystack (case-insensitive, dash-insensitive)
int contains_substring_safe(const char* haystack, const char* needle) {
    if (!haystack || !needle) return 0;
    
    // Validate input lengths
    size_t h_len = strnlen(haystack, MAX_GLASS_NAME_LEN);
    size_t n_len = strnlen(needle, MAX_SEARCH_TERM_LEN);
    
    if (h_len == 0 || n_len == 0 || h_len >= MAX_GLASS_NAME_LEN || n_len >= MAX_SEARCH_TERM_LEN) {
        return 0;
    }
    
    // Allocate normalized buffers safely
    char* haystack_normalized = malloc(h_len + 1);
    char* needle_normalized = malloc(n_len + 1);
    
    if (!haystack_normalized || !needle_normalized) {
        free(haystack_normalized);
        free(needle_normalized);
        return 0;
    }
    
    // Create normalized copies (lowercase, no dashes)
    if (normalize_string_safe(haystack, haystack_normalized, h_len + 1) != 0 ||
        normalize_string_safe(needle, needle_normalized, n_len + 1) != 0) {
        free(haystack_normalized);
        free(needle_normalized);
        return 0;
    }
    
    int result = strstr(haystack_normalized, needle_normalized) != NULL;
    
    free(haystack_normalized);
    free(needle_normalized);
    
    return result;
}

// Function to check if manufacturer matches any of the specified catalogs
int matches_catalog(const char* manufacturer, const char* catalog_list[], int catalog_count) {
    if (catalog_count == 0) return 1; // No filter = show all
    
    for (int i = 0; i < catalog_count; i++) {
        // Case-insensitive comparison
        if (strcasecmp(manufacturer, catalog_list[i]) == 0) {
            return 1;
        }
    }
    return 0;
}

// Function to validate search term input
int validate_search_term(const char* term) {
    if (!term) return 0;
    
    size_t len = strnlen(term, MAX_SEARCH_TERM_LEN);
    if (len == 0 || len >= MAX_SEARCH_TERM_LEN) return 0;
    
    // Check for dangerous characters
    for (size_t i = 0; i < len; i++) {
        char c = term[i];
        if (c == '\0') break;
        // Allow alphanumeric, dash, space, and 'x' for glass codes
        if (!isalnum(c) && c != '-' && c != ' ' && c != 'x' && c != 'X') {
            return 0;
        }
    }
    
    return 1;
}

// Function to check if a search term is a glass code pattern
// Glass code pattern: exactly 6 characters, contains only digits and/or 'x'
int is_glass_code_pattern(const char* term) {
    if (!term) return 0;
    
    size_t len = strnlen(term, GLASS_CODE_LEN + 1);
    if (len != GLASS_CODE_LEN) return 0;
    
    for (size_t i = 0; i < GLASS_CODE_LEN; i++) {
        char c = term[i];
        if (c != 'x' && c != 'X' && !isdigit(c)) {
            return 0; // Invalid character
        }
    }
    
    return 1; // All characters are digits or 'x'
}

// Function to safely check if a glass code matches a pattern
// Pattern can contain 'x' as wildcards, or be an exact 6-digit match
int matches_glass_code_pattern_safe(const char* glass_code, const char* pattern) {
    if (!glass_code || !pattern) return 0;
    
    size_t code_len = strnlen(glass_code, 20);  // Glass codes can be longer than 6
    size_t pattern_len = strnlen(pattern, GLASS_CODE_LEN + 1);
    
    if (code_len < GLASS_CODE_LEN || pattern_len != GLASS_CODE_LEN) return 0;
    
    // Extract first 6 digits from glass_code safely
    char code_digits[GLASS_CODE_LEN + 1];
    size_t digit_count = 0;
    
    for (size_t i = 0; i < code_len && digit_count < GLASS_CODE_LEN; i++) {
        if (isdigit(glass_code[i])) {
            code_digits[digit_count++] = glass_code[i];
        }
    }
    
    if (digit_count < GLASS_CODE_LEN) return 0; // Not enough digits
    code_digits[GLASS_CODE_LEN] = '\0';
    
    // Check if pattern has any wildcards
    int has_wildcards = 0;
    for (size_t i = 0; i < GLASS_CODE_LEN; i++) {
        if (tolower(pattern[i]) == 'x') {
            has_wildcards = 1;
            break;
        }
    }
    
    if (!has_wildcards) {
        // Exact match comparison
        return strcmp(code_digits, pattern) == 0;
    } else {
        // Wildcard pattern matching
        for (size_t i = 0; i < GLASS_CODE_LEN; i++) {
            char p = tolower(pattern[i]);
            if (p != 'x' && p != code_digits[i]) {
                return 0;
            }
        }
        return 1;
    }
}

void print_usage(const char* program_name) {
    printf("fgla - Find Glass utility\n");
    printf("Usage: %s [OPTIONS] <search_term>\n", program_name);
    printf("\n");
    printf("Search for optical glasses by name or glass code\n");
    printf("- Name search: case-insensitive, dash-insensitive partial matching\n");
    printf("- Glass code search: 6-digit exact match (e.g., '517642') or pattern with 'x' wildcards (e.g., '51x64x')\n");
    printf("\n");
    printf("Options:\n");
    printf("  -c <catalogs>   Search only specified catalog(s) (case-insensitive)\n");
    printf("                  Multiple catalogs: -c SCHOTT HOYA CDGM Ohara\n");
    printf("                  If not specified, searches all catalogs\n");
    printf("  -f <format>     Output format: csv, table, json (default: csv)\n");
    printf("\n");
    printf("Examples:\n");
    printf("  %s BK                    # Find all glasses containing 'BK'\n", program_name);
    printf("  %s 517642                # Find glasses with exact glass code\n", program_name);
    printf("  %s 51x64x                # Find glasses with glass code matching pattern\n", program_name);
    printf("  %s -c SCHOTT \"N-SF\"      # Find N-SF glasses in SCHOTT catalog only\n", program_name);
    printf("  %s -f table BK7          # Display results in table format\n", program_name);
    printf("  %s -f json -c HOYA nsf   # Output HOYA NSF glasses as JSON\n", program_name);
}

// Error handling with detailed messages
typedef enum {
    FGLA_SUCCESS = 0,
    FGLA_ERROR_INVALID_ARGS = 1,
    FGLA_ERROR_INVALID_SEARCH_TERM = 2,
    FGLA_ERROR_NO_DATABASE = 3,
    FGLA_ERROR_NO_MATCHES = 4,
    FGLA_ERROR_MEMORY = 5
} FglaResult;

void print_error_with_suggestion(FglaResult error, const char* context) {
    switch (error) {
        case FGLA_ERROR_INVALID_SEARCH_TERM:
            fprintf(stderr, "Error: Invalid search term '%s'\n", context ? context : "");
            fprintf(stderr, "Search terms must be 1-%d characters and contain only letters, numbers, dashes, spaces, or 'x'\n", MAX_SEARCH_TERM_LEN - 1);
            fprintf(stderr, "Examples: 'BK7', '517642', '51x64x'\n");
            break;
        case FGLA_ERROR_NO_DATABASE:
            fprintf(stderr, "Error: Could not load glass database.\n");
            fprintf(stderr, "Suggestions:\n");
            fprintf(stderr, "  1. Run 'python scripts/excel_to_json.py data/xlsx/ -o data/json/glasses.json'\n");
            fprintf(stderr, "  2. Check that data/json/glasses.json exists and is readable\n");
            fprintf(stderr, "  3. Verify current working directory with 'pwd'\n");
            break;
        case FGLA_ERROR_NO_MATCHES:
            fprintf(stderr, "No glasses found matching '%s'\n", context ? context : "");
            fprintf(stderr, "Try:\n");
            fprintf(stderr, "  - A shorter or more general search term\n");
            fprintf(stderr, "  - Checking spelling\n");
            fprintf(stderr, "  - Using different manufacturers with -c option\n");
            break;
        default:
            fprintf(stderr, "Error: %s\n", context ? context : "Unknown error");
            break;
    }
}

// Output formatting functions
void print_header(OutputFormat format, u32 found_count, const char* search_term, int is_glass_code_search) {
    switch (format) {
        case OUTPUT_CSV:
            if (is_glass_code_search) {
                printf("Found %u glasses matching glass code pattern \"%s\"\n", found_count, search_term);
            } else {
                printf("Found %u glasses matching \"%s\"\n", found_count, search_term);
            }
            printf("Name,nd,vd,Glass Code,Manufacturer\n");
            break;
            
        case OUTPUT_TABLE:
            if (is_glass_code_search) {
                printf("Found %u glasses matching glass code pattern \"%s\"\n\n", found_count, search_term);
            } else {
                printf("Found %u glasses matching \"%s\"\n\n", found_count, search_term);
            }
            printf("%-20s %8s %8s %10s %12s\n", "Name", "nd", "vd", "Glass Code", "Manufacturer");
            printf("%-20s %8s %8s %10s %12s\n", "----", "--", "--", "----------", "------------");
            break;
            
        case OUTPUT_JSON:
            printf("{\n");
            printf("  \"search_term\": \"%s\",\n", search_term);
            printf("  \"search_type\": \"%s\",\n", is_glass_code_search ? "glass_code" : "name");
            printf("  \"found_count\": %u,\n", found_count);
            printf("  \"glasses\": [\n");
            break;
    }
}

void print_glass_result(OutputFormat format, const Glass* glass, const char* glass_name, int is_first, int is_last) {
    switch (format) {
        case OUTPUT_CSV:
            printf("%s,%.5f,%.2f,%s,%s\n", 
                   glass_name, 
                   glass->refractiveIndex, 
                   glass->abbeNumber,
                   (const char*)glass->glass_code,
                   (const char*)glass->manufacturer);
            break;
            
        case OUTPUT_TABLE:
            printf("%-20s %8.5f %8.2f %10s %12s\n", 
                   glass_name, 
                   glass->refractiveIndex, 
                   glass->abbeNumber,
                   (const char*)glass->glass_code,
                   (const char*)glass->manufacturer);
            break;
            
        case OUTPUT_JSON:
            printf("%s    {\n", is_first ? "" : ",\n");
            printf("      \"name\": \"%s\",\n", glass_name);
            printf("      \"nd\": %.5f,\n", glass->refractiveIndex);
            printf("      \"vd\": %.2f,\n", glass->abbeNumber);
            printf("      \"glass_code\": \"%s\",\n", (const char*)glass->glass_code);
            printf("      \"manufacturer\": \"%s\"\n", (const char*)glass->manufacturer);
            printf("    }");
            break;
    }
}

void print_footer(OutputFormat format) {
    if (format == OUTPUT_JSON) {
        printf("\n  ]\n}\n");
    }
}

int main(int argc, char* argv[]) {
    const char* search_term = NULL;
    const char* catalog_list[MAX_CATALOG_COUNT]; // Support up to MAX_CATALOG_COUNT catalogs
    int catalog_count = 0;
    OutputFormat output_format = OUTPUT_CSV; // Default format
    
    // Parse command line arguments
    int i = 1;
    while (i < argc) {
        if (strcmp(argv[i], "-c") == 0) {
            // Collect catalog names after -c until next option or unknown argument
            i++; // Skip -c
            const char* known_catalogs[] = {"SCHOTT", "HOYA", "CDGM", "Ohara", NULL};
            
            while (i < argc && argv[i][0] != '-') {
                // Check if this is a known catalog
                int is_catalog = 0;
                for (int j = 0; known_catalogs[j] != NULL; j++) {
                    if (strcasecmp(argv[i], known_catalogs[j]) == 0) {
                        is_catalog = 1;
                        break;
                    }
                }
                
                if (is_catalog) {
                    if (catalog_count >= MAX_CATALOG_COUNT - 1) { // Leave room for NULL terminator
                        fprintf(stderr, "Error: Too many catalogs specified (maximum %d)\n", MAX_CATALOG_COUNT - 1);
                        return FGLA_ERROR_INVALID_ARGS;
                    }
                    catalog_list[catalog_count++] = argv[i];
                    i++;
                } else {
                    // Not a known catalog, stop collecting catalogs
                    break;
                }
            }
            if (catalog_count == 0) {
                fprintf(stderr, "Error: -c option requires at least one catalog name\n");
                print_usage(argv[0]);
                return FGLA_ERROR_INVALID_ARGS;
            }
        } else if (strcmp(argv[i], "-f") == 0) {
            // Format option
            i++; // Skip -f
            if (i >= argc) {
                fprintf(stderr, "Error: -f option requires a format argument\n");
                print_usage(argv[0]);
                return FGLA_ERROR_INVALID_ARGS;
            }
            
            if (strcmp(argv[i], "csv") == 0) {
                output_format = OUTPUT_CSV;
            } else if (strcmp(argv[i], "table") == 0) {
                output_format = OUTPUT_TABLE;
            } else if (strcmp(argv[i], "json") == 0) {
                output_format = OUTPUT_JSON;
            } else {
                fprintf(stderr, "Error: Unknown format '%s'. Supported formats: csv, table, json\n", argv[i]);
                return FGLA_ERROR_INVALID_ARGS;
            }
            i++;
        } else if (argv[i][0] == '-') {
            fprintf(stderr, "Error: Unknown option '%s'\n", argv[i]);
            print_usage(argv[0]);
            return FGLA_ERROR_INVALID_ARGS;
        } else {
            if (search_term != NULL) {
                fprintf(stderr, "Error: Multiple search terms not allowed\n");
                print_usage(argv[0]);
                return FGLA_ERROR_INVALID_ARGS;
            }
            search_term = argv[i];
            i++;
        }
    }
    
    catalog_list[catalog_count] = NULL; // NULL-terminate the list
    
    if (search_term == NULL) {
        print_usage(argv[0]);
        return FGLA_ERROR_INVALID_ARGS;
    }
    
    // Validate search term
    if (!validate_search_term(search_term)) {
        print_error_with_suggestion(FGLA_ERROR_INVALID_SEARCH_TERM, search_term);
        return FGLA_ERROR_INVALID_SEARCH_TERM;
    }
    
    // Try to load glass data from multiple possible locations
    b32 loaded = 0;
    const char* json_paths[] = {
        "data/json/glasses.json",
        "../data/json/glasses.json", 
        "glasses.json",
        NULL
    };
    
    // Try to load JSON file
    const char* successful_path = NULL;
    for (int i = 0; json_paths[i] && !successful_path; i++) {
        // Test if we can load from this path (always try all catalogs for path testing)
        if (load_glasses_from_json((const byte*)json_paths[i], NULL)) {
            successful_path = json_paths[i];
        }
    }
    
    if (!successful_path) {
        print_error_with_suggestion(FGLA_ERROR_NO_DATABASE, NULL);
        fprintf(stderr, "Tried these locations:\n");
        for (int i = 0; json_paths[i]; i++) {
            fprintf(stderr, "  - %s\n", json_paths[i]);
        }
        return FGLA_ERROR_NO_DATABASE;
    }
    
    // Load all glasses first, then filter by catalog during display
    loaded = load_glasses_from_json((const byte*)successful_path, NULL);
    
    u32 glass_count = get_glass_count();
    u32 found_count = 0;
    
    // Determine search type
    int is_glass_code_search = is_glass_code_pattern(search_term);
    
    // Pre-allocate matches array for performance (avoids double iteration)
    u32* matching_indices = malloc(glass_count * sizeof(u32));
    if (!matching_indices) {
        fprintf(stderr, "Error: Memory allocation failed\n");
        cleanup_glass_data();
        return FGLA_ERROR_MEMORY;
    }
    
    // Single pass: find and store matches
    found_count = 0;
    for (u32 i = 0; i < glass_count; i++) {
        const Glass* glass = get_glass(i);
        if (!glass) continue;
        
        const char* glass_name = (const char*)get_glass_name(i);
        if (!glass_name) continue;
        
        int matches = 0;
        
        if (is_glass_code_search) {
            // Glass code pattern search
            const char* glass_code = (const char*)glass->glass_code;
            if (glass_code && matches_glass_code_pattern_safe(glass_code, search_term)) {
                matches = 1;
            }
        } else {
            // Name search
            if (contains_substring_safe(glass_name, search_term)) {
                matches = 1;
            }
        }
        
        // Check if this glass matches the search term and catalog filter
        if (matches && matches_catalog((const char*)glass->manufacturer, catalog_list, catalog_count)) {
            matching_indices[found_count++] = i;
        }
    }
    
    // Output results
    if (found_count == 0) {
        print_error_with_suggestion(FGLA_ERROR_NO_MATCHES, search_term);
        free(matching_indices);
        cleanup_glass_data();
        return FGLA_ERROR_NO_MATCHES;
    }
    
    // Print header in requested format
    print_header(output_format, found_count, search_term, is_glass_code_search);
    
    // Display matches from stored indices
    for (u32 j = 0; j < found_count; j++) {
        u32 i = matching_indices[j];
        const Glass* glass = get_glass(i);
        const char* glass_name = (const char*)get_glass_name(i);
        
        if (glass && glass_name) {
            print_glass_result(output_format, glass, glass_name, j == 0, j == found_count - 1);
        }
    }
    
    // Print footer in requested format
    print_footer(output_format);
    
    free(matching_indices);
    
    // Cleanup
    cleanup_glass_data();
    
    return FGLA_SUCCESS;
}