/**
 * registry.c — In-memory slot registry + JSON persistence.
 */
#include "registry.h"
#include "slot.h"

#include <stdio.h>
#include <string.h>
#include <time.h>

fc_registry_entry_t g_registry[FC_MAX_SLOTS];
int                 g_registry_count = 0;

static const char *REGISTRY_JSON = "/dev/shm/framecache/registry.json";

void registry_add(struct fc_slot *slot)
{
    for (int i = 0; i < FC_MAX_SLOTS; i++) {
        if (!g_registry[i].active) {
            g_registry[i].active = 1;
            g_registry[i].slot   = slot;
            strncpy(g_registry[i].slot_id, fc_slot_id(slot),
                    FC_MAX_SLOT_ID - 1);
            g_registry_count++;
            registry_write_json();
            return;
        }
    }
    fprintf(stderr, "[framecache] registry full (%d slots)\n", FC_MAX_SLOTS);
}

void registry_remove(const char *slot_id)
{
    for (int i = 0; i < FC_MAX_SLOTS; i++) {
        if (g_registry[i].active &&
            strncmp(g_registry[i].slot_id, slot_id, FC_MAX_SLOT_ID) == 0)
        {
            g_registry[i].active = 0;
            g_registry[i].slot   = NULL;
            g_registry[i].slot_id[0] = '\0';
            g_registry_count--;
            registry_write_json();
            return;
        }
    }
}

struct fc_slot *registry_find(const char *slot_id)
{
    for (int i = 0; i < FC_MAX_SLOTS; i++) {
        if (g_registry[i].active &&
            strncmp(g_registry[i].slot_id, slot_id, FC_MAX_SLOT_ID) == 0)
        {
            return g_registry[i].slot;
        }
    }
    return NULL;
}

void registry_write_json(void)
{
    FILE *f = fopen(REGISTRY_JSON, "w");
    if (!f) return;

    fprintf(f, "{\n  \"version\": 1,\n  \"slots\": {\n");

    int first = 1;
    for (int i = 0; i < FC_MAX_SLOTS; i++) {
        if (!g_registry[i].active) continue;
        fc_header_t *hdr = fc_slot_header(g_registry[i].slot);

        char ts[32];
        time_t now = time(NULL);
        struct tm *t = gmtime(&now);
        strftime(ts, sizeof ts, "%Y-%m-%dT%H:%M:%SZ", t);

        if (!first) fprintf(f, ",\n");
        first = 0;

        fprintf(f,
            "    \"%s\": {\n"
            "      \"shm_path\": \"%s\",\n"
            "      \"sem_name\": \"%s\",\n"
            "      \"width\": %u,\n"
            "      \"height\": %u,\n"
            "      \"fps_num\": %u,\n"
            "      \"fps_den\": %u,\n"
            "      \"pixel_format\": \"UYVY422\",\n"
            "      \"source_type\": \"%s\",\n"
            "      \"frame_size\": %u,\n"
            "      \"ring_depth\": %u,\n"
            "      \"created_at\": \"%s\"\n"
            "    }",
            g_registry[i].slot_id,
            fc_slot_shm_path(g_registry[i].slot),
            fc_slot_sem_name(g_registry[i].slot),
            hdr->width, hdr->height,
            hdr->fps_num, hdr->fps_den,
            hdr->source_type,
            hdr->frame_size,
            hdr->ring_depth,
            ts
        );
    }

    fprintf(f, "\n  }\n}\n");
    fclose(f);
}