#include "rvprof_internal.h"

static void rvprof_atexit_handler(void){
    if(g_rvprof.initialized) rvprof_context_cleanup();
}

static void register_atexit_handler(void){
    static int registered = 0;
    if (!registered){
        atexit(rvprof_atexit_handler);
        registered = 1;
    }
}


void rvprof_init(const char* output_file){
    if (g_rvprof.initialized) return;

    // enable usage of cygnus hooks, disable with RVPROF_DISABLE_HOOKS env variable
    g_rvprof.config.enable_hooks = 1;
    // merge regions of same names in output, disable with RVPROF_DISABLE_MERGE env variable
    g_rvprof.config.merge_regions =1;
    // set output file name, auto-detected, override with RVPROF_OUTPUT env variable
    g_rvprof.config.output_filename = NULL;
    // set program name, auto-detected
    g_rvprof.config.program_name = NULL;

    char* disable_hooks = getenv("RVPROF_DISABLE_HOOKS");
    if (disable_hooks && strcmp(disable_hooks, "1") == 0){
        g_rvprof.config.enable_hooks = 0;
    }

    char* disable_merge = getenv("RVPROF_DISABLE_MERGE");
    if (disable_merge && strcmp(disable_merge, "1") == 0){
        g_rvprof.config.merge_regions = 0;
    }

    char* env_output = getenv("RVPROF_OUTPUT");
    const char* filename;

    // determine output filename
    if (output_file && strlen(output_file) > 0){
        filename = output_file;
    } else if (env_output && strlen(env_output) > 0){
        filename = env_output;
    } else {
        filename = rvprof_utils_generate_output_filename();
    }

    g_rvprof.output_file = fopen(filename, "w");
    if(!g_rvprof.output_file) return;

    rvprof_error_t timing_result = rvprof_timing_init();
    if (timing_result != RVPROF_SUCCESS) return;

    rvprof_symbols_init(g_rvprof.config.program_name); // in case symbol resolution fails, just addresses are printed later


    // rest of global state
    g_rvprof.stack_ptr = -1;
    g_rvprof.initialized = 1;
    g_rvprof.auto_initialized = 0;
    g_rvprof.total_program_time = 0;
    g_rvprof.total_program_cycles = 0;
    g_rvprof.total_memory_allocated = 0;


    // initialize dynamic arrays with zeros
    memset(&g_rvprof.regions, 0, sizeof(g_rvprof.regions));
    memset(&g_rvprof.functions, 0, sizeof(g_rvprof.functions));
    memset(&g_rvprof.stacks,0,sizeof(g_rvprof.stacks));

    // register atexit handler to automate cleanup
    register_atexit_handler();
}

void rvprof_set_program_name(const char* program_name){
    if (g_rvprof.config.program_name){
        rvprof_free(g_rvprof.config.program_name, strlen(g_rvprof.config.program_name)+1);
    }
    if (program_name) {
        g_rvprof.config.program_name = rvprof_malloc(strlen(program_name)+1);
        if (g_rvprof.config.program_name) {
            strcpy(g_rvprof.config.program_name, program_name);
        }
    }
}