example.c

#include <stdio.h>
#include <stdlib.h>

#define JSON_IMPLEMENTATION
#include "./json.h"

char *read_file(const char *filename);

int main(int argc, char **argv) {
  // Read JSON from file
  char *mission_json = read_file("example.json");
  if (!mission_json) {
    return 1;
  }

  printf("=== ARTEMIS III MISSION DATA PARSER ===\n\n");

  // Example 1: Extract mission overview (6 fields in one call)
  printf("1. MISSION OVERVIEW\n");
  printf("-------------------\n");
  
  const char *mission_keys[] = {
    "mission.name",
    "mission.launch_date",
    "mission.status",
    "mission.duration_days",
    "mission.budget_millions",
    "mission.is_crewed"
  };
  
  char **mission_data = json_gets(mission_json, mission_keys, 6);
  if (mission_data) {
    printf("Mission: %s\n", mission_data[0]);
    printf("Launch Date: %s\n", mission_data[1]);
    printf("Status: %s\n", mission_data[2]);
    printf("Duration: %s days | Budget: $%s million | Crewed: %s\n", 
           mission_data[3], mission_data[4], mission_data[5]);
    
    for (int i = 0; i < 6; i++) free(mission_data[i]);
    free(mission_data);
  }

  // Example 2: Array access - fetch all crew members
  printf("\n2. CREW ROSTER (array access)\n");
  printf("------------------------------\n");
  
  const char *crew_keys[] = {
    "crew.0.name", "crew.0.role",
    "crew.1.name", "crew.1.role",
    "crew.2.name", "crew.2.role",
    "crew.3.name", "crew.3.role"
  };
  
  char **crew = json_gets(mission_json, crew_keys, 8);
  if (crew) {
    for (int i = 0; i < 4; i++) {
      printf("  %s - %s\n", crew[i*2], crew[i*2+1]);
    }
    for (int i = 0; i < 8; i++) free(crew[i]);
    free(crew);
  }

  // Example 3: Deep nesting - spacecraft systems
  printf("\n3. SPACECRAFT SYSTEMS (deep nesting)\n");
  printf("-------------------------------------\n");
  
  const char *spacecraft_keys[] = {
    "spacecraft.name",
    "spacecraft.manufacturer",
    "spacecraft.systems.propulsion",
    "spacecraft.systems.life_support",
    "spacecraft.systems.power"
  };
  
  char **spacecraft = json_gets(mission_json, spacecraft_keys, 5);
  if (spacecraft) {
    printf("%s (by %s)\n", spacecraft[0], spacecraft[1]);
    printf("  Propulsion: %s\n", spacecraft[2]);
    printf("  Life Support: %s\n", spacecraft[3]);
    printf("  Power: %s\n", spacecraft[4]);
    
    for (int i = 0; i < 5; i++) free(spacecraft[i]);
    free(spacecraft);
  }

  // Example 4: Coordinates and numeric values
  printf("\n4. LANDING COORDINATES\n");
  printf("----------------------\n");
  
  const char *location_keys[] = {
    "landing_site.name",
    "landing_site.coordinates.latitude",
    "landing_site.coordinates.longitude",
    "landing_site.elevation_meters"
  };
  
  char **location = json_gets(mission_json, location_keys, 4);
  if (location) {
    printf("Site: %s\n", location[0]);
    printf("Coordinates: %s°, %s° | Elevation: %s m\n", 
           location[1], location[2], location[3]);
    
    for (int i = 0; i < 4; i++) free(location[i]);
    free(location);
  }

  // Example 5: String array values
  printf("\n5. MISSION OBJECTIVES\n");
  printf("---------------------\n");
  
  const char *obj_keys[] = {
    "objectives.0", "objectives.1", "objectives.2", "objectives.3"
  };
  
  char **objectives = json_gets(mission_json, obj_keys, 4);
  if (objectives) {
    for (int i = 0; i < 4; i++) {
      printf("  %d. %s\n", i+1, objectives[i]);
    }
    for (int i = 0; i < 4; i++) free(objectives[i]);
    free(objectives);
  }

  // Example 6: Mixed data from different sections
  printf("\n6. MISSION SUMMARY (mixed paths)\n");
  printf("---------------------------------\n");
  
  const char *summary_keys[] = {
    "mission.name",
    "crew.0.name",
    "spacecraft.name",
    "landing_site.name"
  };
  
  char **summary = json_gets(mission_json, summary_keys, 4);
  if (summary) {
    printf("%s: Commander %s will pilot %s to %s\n",
           summary[0], summary[1], summary[2], summary[3]);
    
    for (int i = 0; i < 4; i++) free(summary[i]);
    free(summary);
  }

  // Example 7: Single value with json_get()
  printf("\n7. SINGLE VALUE (json_get)\n");
  printf("--------------------------\n");
  
  char *commander = json_get(mission_json, "crew.0.specialization");
  printf("Commander specialization: %s\n", commander ? commander : "N/A");
  free(commander);

  // Example 8: Null/missing values
  printf("\n8. ERROR HANDLING\n");
  printf("-----------------\n");
  
  const char *test_keys[] = {
    "mission.name",
    "invalid.key",
    "crew.99.name"
  };
  
  char **test = json_gets(mission_json, test_keys, 3);
  if (test) {
    printf("Valid: %s\n", test[0] ? test[0] : "NULL");
    printf("Invalid key: %s\n", test[1] ? test[1] : "NULL");
    printf("Out of bounds: %s\n", test[2] ? test[2] : "NULL");
    
    for (int i = 0; i < 3; i++) free(test[i]);
    free(test);
  }

  printf("\n=== END OF DEMO ===\n");
  
  free(mission_json);
  return 0;
}

// Helper function to read entire file into a string
char *read_file(const char *filename) {
  FILE *file = fopen(filename, "r");
  if (!file) {
    fprintf(stderr, "Error: Could not open file '%s'\n", filename);
    return NULL;
  }

  fseek(file, 0, SEEK_END);
  long file_size = ftell(file);
  fseek(file, 0, SEEK_SET);

  char *buffer = (char *)malloc(file_size + 1);
  if (!buffer) {
    fprintf(stderr, "Error: Memory allocation failed\n");
    fclose(file);
    return NULL;
  }

  size_t bytes_read = fread(buffer, 1, file_size, file);
  buffer[bytes_read] = '\0';

  fclose(file);
  return buffer;
}