#include "rss_html_common.h"
#include "json.h"
#include "fileutils.h"
#include <string.h>
#include <stdio.h>
#include <time.h>
#include <assert.h>

int write_plugin_json_to_file(const char *dir, const char *filename, const char *url, const char *updated, const char *start_after, const char *start_after_url, const char *plugin_name) {
    struct json_string_s title_json_key;
    create_json_string(&title_json_key, "title", 5);

    struct json_string_s title_json_value_str;
    create_json_string(&title_json_value_str, start_after, start_after ? strlen(start_after) : 0);
    struct json_value_s title_json_value;
    init_json_value_str(&title_json_value, &title_json_value_str);

    struct json_string_s time_json_key;
    create_json_string(&time_json_key, "time", 4);

    struct json_string_s time_value_str;
    create_json_string(&time_value_str, updated, strlen(updated));
    struct json_value_s time_json_value;
    init_json_value_str(&time_json_value, &time_value_str);

    struct json_string_s url_json_key;
    create_json_string(&url_json_key, "url", 3);

    struct json_string_s url_value_str;
    create_json_string(&url_value_str, start_after_url, start_after_url ? strlen(start_after_url) : 0);
    struct json_value_s url_json_value;
    init_json_value_str(&url_json_value, &url_value_str);

    struct json_string_s plugin_json_key;
    create_json_string(&plugin_json_key, "plugin", 6);

    struct json_string_s plugin_json_value_str;
    create_json_string(&plugin_json_value_str, plugin_name, plugin_name ? strlen(plugin_name) : 0);
    struct json_value_s plugin_json_value;
    init_json_value_str(&plugin_json_value, &plugin_json_value_str);

    struct json_string_s link_json_key;
    create_json_string(&link_json_key, "link", 4);

    struct json_string_s link_json_value_str;
    create_json_string(&link_json_value_str, url, strlen(url));
    struct json_value_s link_json_value;
    init_json_value_str(&link_json_value, &link_json_value_str);

    struct json_string_s updated_json_key;
    create_json_string(&updated_json_key, "updated", 7);

    struct json_string_s updated_json_value_str;
    create_json_string(&updated_json_value_str, updated, strlen(updated));
    struct json_value_s updated_json_value;
    init_json_value_str(&updated_json_value, &updated_json_value_str);

    struct json_string_s downloaded_json_key;
    create_json_string(&downloaded_json_key, "downloaded", 10);

    struct json_object_s downloaded_json;
    downloaded_json.start = NULL;
    downloaded_json.length = 0;

    struct json_value_s downloaded_json_value;
    downloaded_json_value.payload = &downloaded_json;
    downloaded_json_value.type = json_type_object;

    struct json_object_element_s downloaded_title_element;
    downloaded_title_element.name = &title_json_key;
    downloaded_title_element.value = &title_json_value;

    struct json_object_element_s downloaded_time_element;
    downloaded_time_element.name = &time_json_key;
    downloaded_time_element.value = &time_json_value;

    struct json_object_element_s downloaded_url_element;
    downloaded_url_element.name = &url_json_key;
    downloaded_url_element.value = &url_json_value;

    downloaded_title_element.next = &downloaded_time_element;
    downloaded_time_element.next = &downloaded_url_element;
    downloaded_url_element.next = NULL;

    struct json_array_s downloaded_json_array;
    downloaded_json_array.start = NULL;
    downloaded_json_array.length = 0;
    struct json_array_element_s downloaded_json_array_element;

    if(start_after) {
        downloaded_json.start = &downloaded_title_element;
        downloaded_json.length = 3;

        downloaded_json_array_element.value = &downloaded_json_value;
        downloaded_json_array_element.next = NULL;
        downloaded_json_array.start = &downloaded_json_array_element;
        downloaded_json_array.length = 1;
    }

    struct json_value_s downloaded_json_array_value;
    downloaded_json_array_value.payload = &downloaded_json_array;
    downloaded_json_array_value.type = json_type_array;

    struct json_object_s json_root;
    json_root.length = 3;
    
    struct json_object_element_s link_element;
    link_element.name = &link_json_key;
    link_element.value = &link_json_value;

    struct json_object_element_s updated_element;
    updated_element.name = &updated_json_key;
    updated_element.value = &updated_json_value;

    struct json_object_element_s downloaded_element;
    downloaded_element.name = &downloaded_json_key;
    downloaded_element.value = &downloaded_json_array_value;

    struct json_object_element_s plugin_element;
    plugin_element.name = &plugin_json_key;
    plugin_element.value = &plugin_json_value;

    link_element.next = &updated_element;
    updated_element.next = &downloaded_element;
    downloaded_element.next = NULL;

    if(plugin_name) {
        json_root.start = &plugin_element;
        plugin_element.next = &link_element;
    } else {
        json_root.start = &link_element;
    }

    struct json_value_s json_root_value;
    json_root_value.payload = &json_root;
    json_root_value.type = json_type_object;
    size_t json_body_size = 0;
    char *json_body_str = json_write_pretty(&json_root_value, "    ", "\n", &json_body_size);
    if(!json_body_str) {
        fprintf(stderr, "Failed to write json data to file %s/%s\n", dir, filename);
        return -1;
    }

    /* Workaround json bug (?) */
    json_body_size = strlen(json_body_str);

    int result = file_overwrite_in_dir(dir, filename, json_body_str, json_body_size);
    free(json_body_str);
    return result;
}

static struct json_array_element_s* get_last_element_in_json_array(struct json_array_s *json_array) {
    struct json_array_element_s *json_element = json_array->start;
    while(json_element) {
        struct json_array_element_s *next_json_element = json_element->next;
        if(next_json_element)
            json_element = next_json_element;
        else
            return json_element;
    }
    return NULL;
}

/* TODO: If this fails in the middle, recover and update the next time somehow */
int tracked_item_update_latest(TrackedItem *tracked_item, char *tracked_dir, DownloadItemsData **download_items, char **filenames, long *timestamps, int num_download_items) {
    if(num_download_items == 0)
        return 0;

    assert(num_download_items <= MAX_UPDATE_ITEMS);
    assert(timestamps);
    int tracked_dir_len = strlen(tracked_dir);
    int result = 0;

    char *item_filepath = tracked_dir;
    strcat(item_filepath, tracked_item->title);
    
    char updated[32];
    assert(sizeof(time_t) == sizeof(long));
    sprintf(updated, "%ld", timestamps[num_download_items - 1]);
    int updated_len = strlen(updated);
    result = file_overwrite_in_dir(item_filepath, "updated", updated, updated_len);
    if(result != 0) {
        fprintf(stderr, "Failed to update %s/updated\n", item_filepath);
        goto cleanup;
    }

    struct json_value_s *updated_field = json_object_get_field_by_name(tracked_item->json_data, "updated");
    if(updated_field) {
        struct json_string_s *updated_json = json_value_as_string(updated_field);
        updated_json->string = updated;
        updated_json->string_size = updated_len;
    } else {
        fprintf(stderr, "Corrupt json for rss item: %s\n", item_filepath);
    }

    struct json_value_s *downloaded_json = json_object_get_field_by_name(tracked_item->json_data, "downloaded");
    struct json_array_s *downloaded_json_array_orig = NULL;
    struct json_array_s *downloaded_json_array = NULL;

    struct json_array_s new_downloaded_array;
    new_downloaded_array.length = 1;
    new_downloaded_array.start = NULL;

    struct json_value_s new_downloaded_array_val;
    new_downloaded_array_val.payload = &new_downloaded_array;
    new_downloaded_array_val.type = json_type_array;

    struct json_string_s downloaded_json_key;
    create_json_string(&downloaded_json_key, "downloaded", 10);

    struct json_object_element_s new_downloaded_array_obj_el;
    new_downloaded_array_obj_el.name = &downloaded_json_key;
    new_downloaded_array_obj_el.value = &new_downloaded_array_val;

    if(downloaded_json) {
        downloaded_json_array = json_value_as_array(downloaded_json);
        if(!downloaded_json_array) {
            fprintf(stderr, "Corrupt json for rss item: %s\n", item_filepath);
            result = -1;
            goto cleanup;
        }
        downloaded_json_array_orig = downloaded_json_array;
    } else {
        downloaded_json_array = &new_downloaded_array;
    }

    struct json_string_s title_json_key;
    create_json_string(&title_json_key, "title", 5);

    struct json_string_s filename_json_key;
    create_json_string(&filename_json_key, "filename", 8);

    struct json_string_s time_json_key;
    create_json_string(&time_json_key, "time", 4);

    struct json_string_s url_json_key;
    create_json_string(&url_json_key, "url", 3);

    struct json_string_s title_json_value_str[MAX_UPDATE_ITEMS];
    struct json_value_s title_json_value[MAX_UPDATE_ITEMS];
    struct json_string_s filename_json_value_str[MAX_UPDATE_ITEMS];
    struct json_value_s filename_json_value[MAX_UPDATE_ITEMS];
    struct json_string_s time_value_str[MAX_UPDATE_ITEMS];
    struct json_value_s time_json_value[MAX_UPDATE_ITEMS];
    struct json_string_s url_value_str[MAX_UPDATE_ITEMS];
    struct json_value_s url_json_value[MAX_UPDATE_ITEMS];

    struct json_object_element_s downloaded_title_element[MAX_UPDATE_ITEMS];
    struct json_object_element_s downloaded_filename_element[MAX_UPDATE_ITEMS];
    struct json_object_element_s downloaded_time_element[MAX_UPDATE_ITEMS];
    struct json_object_element_s downloaded_url_element[MAX_UPDATE_ITEMS];

    struct json_object_s new_downloaded_json_obj[MAX_UPDATE_ITEMS];
    struct json_value_s new_downloaded_json_val[MAX_UPDATE_ITEMS];
    struct json_array_element_s new_downloaded_item_element[MAX_UPDATE_ITEMS];

    char items_timestamps[MAX_UPDATE_ITEMS][32];

    struct json_array_element_s *last_downloaded_element = NULL;
    for(int i = 0; i < num_download_items; ++i) {
        create_json_string(&title_json_value_str[i], download_items[i]->title, strlen(download_items[i]->title));
        init_json_value_str(&title_json_value[i], &title_json_value_str[i]);

        if(filenames) {
            create_json_string(&filename_json_value_str[i], filenames[i], strlen(filenames[i]));
            init_json_value_str(&filename_json_value[i], &filename_json_value_str[i]);
        }

        sprintf(items_timestamps[i], "%ld", timestamps[i]);
        int updated_len = strlen(items_timestamps[i]);
        create_json_string(&time_value_str[i], items_timestamps[i], updated_len);
        init_json_value_str(&time_json_value[i], &time_value_str[i]);

        create_json_string(&url_value_str[i], download_items[i]->link, strlen(download_items[i]->link));
        init_json_value_str(&url_json_value[i], &url_value_str[i]);

        downloaded_title_element[i].name = &title_json_key;
        downloaded_title_element[i].value = &title_json_value[i];

        if(filenames) {
            downloaded_filename_element[i].name = &filename_json_key;
            downloaded_filename_element[i].value = &filename_json_value[i];
        }

        downloaded_time_element[i].name = &time_json_key;
        downloaded_time_element[i].value = &time_json_value[i];

        downloaded_url_element[i].name = &url_json_key;
        downloaded_url_element[i].value = &url_json_value[i];

        downloaded_title_element[i].next = &downloaded_time_element[i];
        downloaded_time_element[i].next = &downloaded_url_element[i];
        downloaded_url_element[i].next = NULL;
        if(filenames) {
            downloaded_url_element[i].next = &downloaded_filename_element[i];
            downloaded_filename_element[i].next = NULL;
            new_downloaded_json_obj[i].length = 4;
        } else {
            new_downloaded_json_obj[i].length = 3;
        }

        new_downloaded_json_obj[i].start = &downloaded_title_element[i];

        new_downloaded_json_val[i].payload = &new_downloaded_json_obj[i];
        new_downloaded_json_val[i].type = json_type_object;

        new_downloaded_item_element[i].value = &new_downloaded_json_val[i];
        new_downloaded_item_element[i].next = NULL;

        if(downloaded_json_array->length > 0) {
            if(!last_downloaded_element)
                last_downloaded_element = get_last_element_in_json_array(downloaded_json_array);
    
            if(last_downloaded_element)
                last_downloaded_element->next = &new_downloaded_item_element[i];
            else
                downloaded_json_array->start = &new_downloaded_item_element[i];
    
            last_downloaded_element = &new_downloaded_item_element[i];
            downloaded_json_array->length++;
        } else {
            downloaded_json_array->start = &new_downloaded_item_element[i];
            downloaded_json_array->length = 1;
            last_downloaded_element = &new_downloaded_item_element[i];

            if(!downloaded_json_array_orig) {
                struct json_object_element_s *prev_start = tracked_item->json_data->start;
                tracked_item->json_data->start = &new_downloaded_array_obj_el;
                new_downloaded_array_obj_el.next = prev_start;
                tracked_item->json_data->length++;
            }
        }
    }

    struct json_value_s json_root_value;
    json_root_value.payload = tracked_item->json_data;
    json_root_value.type = json_type_object;

    size_t json_body_size = 0;
    char *json_body_str = json_write_pretty(&json_root_value, "    ", "\n", &json_body_size);
    if(!json_body_str) {
        fprintf(stderr, "Failed to write json data to file %s/data\n", item_filepath);
        result = -1;
        goto cleanup;
    }

    /* Workaround json bug (?) */
    json_body_size = strlen(json_body_str);

    result = file_overwrite_in_dir(item_filepath, "data", json_body_str, json_body_size);
    free(json_body_str);

    cleanup:
    tracked_dir[tracked_dir_len] = '\0';
    return result;
}

struct json_value_s* json_object_get_field_by_name(struct json_object_s *json_obj, const char *name) {
    struct json_object_element_s *obj_element = json_obj->start;
    while(obj_element) {
        if(strcmp(obj_element->name->string, name) == 0)
            return obj_element->value;
        obj_element = obj_element->next;
    }
    return NULL;
}

void create_json_string(struct json_string_s *json_result, const char *str, int len) {
    json_result->string = str;
    json_result->string_size = len;
}

void init_json_value_str(struct json_value_s *json_value, struct json_string_s *json_str) {
    json_value->payload = json_str;
    json_value->type = json_type_string;
}