/******************************************************************************
 *
 *                Copyright (c) 2017-2019 by Löwenware Ltd
 *             Please, refer LICENSE file for legal information
 *
 ******************************************************************************/

/**
 * @file todo.c
 * @author Ilja Kartašov <ik@lowenware.com>
 * @brief AISL ToDo.txt module code file
 *
 * @see https://lowenware.com/
 */

#include <stdlib.h>
#include <inttypes.h>
#include <uuid.h>
#include <string.h>
#include <components/query.h>
#include <components/quick.h>
#include <components/log.h>
#include <cStuff/string.h>
#include <mods/minion.h>


typedef enum {
	  AX_MINION_UNDEFINED
	, AX_MINION_TODAY
	, AX_MINION_CREATE_TASK
	, AX_MINION_READ_TASK
	, AX_MINION_UPDATE_TASK
	, AX_MINION_DELETE_TASK
} AxMinionMode;


struct context {
	struct ax_context root;
	struct ax_query qs;
	struct ax_todo_task task;

	AxMinionMode mode;
};

typedef struct context * Context;


typedef int
(*AxMinionCompare)(void *object1, void *object2);

static const char modName[] = "minion";


static Context
context_new(const char *path, AislHttpMethod method, AxMinion mod)
{
	Context ctx;

	if (!(ctx = (Context)ax_context_new(AX_MODULE(mod))))
		return ctx;

	if (strcmp(path, "today/") == 0)
		ctx->mode = AX_MINION_TODAY;
	else if (strcmp(path, "create/") == 0)
		ctx->mode = AX_MINION_CREATE_TASK;
	else if (strcmp(path, "read/") == 0)
		ctx->mode = AX_MINION_READ_TASK;
	else if (strcmp(path, "update/") == 0)
		ctx->mode = AX_MINION_UPDATE_TASK;
	else if (strcmp(path, "delete/") == 0)
		ctx->mode = AX_MINION_DELETE_TASK;

	ctx->task.priority = AX_TODO_ZERO_PRIORITY;

	return ctx;
}


static void
context_free(Context ctx)
{
	ax_query_release(&ctx->qs);
	ax_todo_task_release(&ctx->task);

	ax_context_free((AxContext)ctx);
}


static int
ax_minion_compare_tasks(AxTodoTask task1, AxTodoTask task2)
{
	if (task1->is_done) {
		if (task2->is_done) {
			if (task1->completed > task2->completed) {
				return -1;
			} else if (task1->completed > task2->completed) {
				return 1;
			}
		} else {
			return 1;
		}
	} else {
		if (task2->is_done) {
			return -1;
		} else {
			if (task1->priority < task2->priority) {
				return -1;
			} else if (task1->priority == task2->priority) {
				if (task1->created > task2->created) {
					return -1;
				} else if (task1->created < task2->created) {
					return 1;
				}
			} else {
				return 1;
			}
		}
	}
	return 0;
}


static int
ax_minion_compare_projects(AxTodoProject proj1, AxTodoProject proj2)
{
	if (proj1->last_completed < proj2->last_completed) {
		return -1;
	} else if (proj1->last_completed > proj2->last_completed) {
		return 1;
	}

	if (proj1->ref_count > proj2->ref_count) {
		return -1;
	} else if (proj1->ref_count < proj2->ref_count) {
		return 1;
	}

	return 0;
}


static int
ax_minion_compare_tags(AxTodoTag tag1, AxTodoTag tag2)
{
	if (tag1->ref_count > tag2->ref_count) {
		return -1;
	} else if (tag1->ref_count < tag2->ref_count) {
		return 1;
	}

	return 0;
}


static void
ax_minion_sort(CStuffList list, AxMinionCompare compare_objects)
{
	int l = list->length, ld = l - 1, i, j;
	void **data = list->items, *swap;

	for (i = 0; i < l; i++) {
		int c = i + 1;
		for (j = ld; j >= c; j--) {
			if (compare_objects((AxTodoTask)data[j], (AxTodoTask)data[j - 1]) == -1) {
				swap = data[j];
				data[j] = data[j - 1];
				data[j - 1] = swap;
			}
		}
	}
}


static void
on_input_dt(const char *val, uint32_t v_len, time_t *p_out)
{
	char str_dt[36 + 1];
	if (!(*p_out) && !(v_len < 10 || v_len > sizeof (str_dt) - 1)) {
		strncpy(str_dt, val, v_len);
		str_dt[v_len] = 0;
		(void) ax_todo__get_dt(str_dt, p_out);
	}
}


static void
on_input_uuid(const char *val, uint32_t v_len, uuid_t uuid_out)
{
	char str_uuid[36 + 1];

	if (v_len == 36) {
		strncpy(str_uuid, val, v_len);
		str_uuid[v_len] = 0;
		uuid_parse(str_uuid, uuid_out);
	}
}


static int
on_input_var(const char *key, uint32_t k_len, const char *val, uint32_t v_len,
		void *p_ctx)
{
	Context ctx = (Context) p_ctx;
	/* AxMinion mod = (AxMinion)((AxContext)ctx)->mod; */
	char **out = NULL;

	if (k_len == 1) {
		if (*key == 't') {
			out = &ctx->task.description;
		} else if (*key == 'x') {
			ctx->task.is_done = (v_len == 4 && strncmp(val, "true", 4) == 0);
		} else if (*key == 'p') {
			if (v_len == 1 && !((*val < 0x41 || *val > 0x5A))) {
				ctx->task.priority = *val;
			}
		}
	} else if (k_len == 2) {
		if (strncmp(key, "id", 2) == 0) {
			on_input_uuid(val, v_len, ctx->task.task_id);
		} else if (strncmp(key, "li", 2) == 0) {
			on_input_uuid(val, v_len, ctx->task.list_id);
		} else if (strncmp(key, "co", 2) == 0) {
			on_input_dt(val, v_len, &ctx->task.completed);
		} else if (strncmp(key, "cr", 2) == 0) {
			on_input_dt(val, v_len, &ctx->task.created);
		}
	}

	if (out && !(*out)) {
		if (cstuff_strncpy(out, val, v_len) == -1)
			return -1;
		ax_query__decode(*out);
		ax_todo__remove_line_break(*out);
	}
	return 0;
}


static AislStatus
on_stream_open(AxMinion mod, const struct aisl_evt_open *evt)
{
	Context ctx;
	AislStream s = (AislStream)evt->evt.source;

	if (!(ctx = context_new(&evt->path[AX_MODULE(mod)->ep_length],
			evt->http_method, mod))) {
		return AISL_MALLOC_ERROR;
	}

	aisl_set_context(s, ctx);

	return AISL_SUCCESS;
}


static AislStatus
on_stream_header(AxMinion mod, const struct aisl_evt_header *evt)
{
	AislStream s = (AislStream)evt->evt.source;
	Context ctx = aisl_get_context(s);

	AX_LOG_DEBUG("header: %s = %s", evt->key, evt->value);

	if (strcmp(evt->key, "content-length") == 0) {
		size_t total = strtoll(evt->value, NULL, 10);

		if(ax_query_init(&ctx->qs, total, on_input_var, (void*)ctx) != 0) {
			ax_quick_response(s, AISL_HTTP_INTERNAL_SERVER_ERROR);
		}
	}
	return AISL_SUCCESS;
}


static AislStatus
on_stream_input(AxMinion mod, const struct aisl_evt_input *evt)
{
	Context ctx = aisl_get_context((AislStream)evt->evt.source);

	AX_LOG_DEBUG("input[%d]: %s", evt->size, evt->data);
	ax_query_feed(&ctx->qs, evt->data, evt->size);

	return AISL_SUCCESS;
}


static void
ax_minion_date2str(time_t tt, char *str_dt, size_t sz)
{
	struct tm *p_tm = gmtime(&tt);
	strftime(str_dt, sz, "%Y-%m-%d", p_tm);
}


static bool
ax_minion_today(AxMinion mod, AislStream s, Context ctx)
{
	/* sprint: [{task1}, {task2}]
	 */
	return true;
}


static bool
ax_minion_create_task(AxMinion mod, AislStream s, Context ctx)
{
	AxTodoTask task;
	char str_uuid[36 + 1];

	if (!(ctx->task.description)) {
		AX_LOG_STATE("%s: !description", modName);
		return false;
	}

	if (uuid_compare(ctx->task.list_id, mod->todo.list_id) != 0) {
		AX_LOG_STATE("%s: !list_id", modName);
		return false;
	}

	if (!(task = ax_todo_task_new(ctx->task.list_id)))
		goto e_system;

	task->is_done = ctx->task.is_done;
	task->priority = ctx->task.priority;
	if (!(task->created = ctx->task.created))
		time(&task->created);
	task->completed = ctx->task.completed;
	task->description = ctx->task.description;
	uuid_copy(task->list_id, ctx->task.list_id);
	ctx->task.description = NULL;

	if (cstuff_list_append(&mod->tasks, task) == -1) {
		ax_todo_task_free(task);
		goto e_system;
	}

	if (ax_todo_write(&mod->todo, &mod->tasks) != AISL_SUCCESS)
		goto e_system;

	if (aisl_header(s, "Content-Type", "text/json") == -1)
		goto e_reject;

	uuid_unparse_lower(task->list_id, str_uuid);

	if (aisl_printf(s, "{\"id\": \"%s\"}", str_uuid) == -1)
		goto e_reject;

	if (aisl_flush(s) != AISL_SUCCESS)
		goto e_reject;

goto finally;

e_reject:
	aisl_reject(s);
	goto finally;

e_system:
	ax_quick_response(s, AISL_HTTP_INTERNAL_SERVER_ERROR);
	goto finally;

finally:
	return true;
}


static void
ax_minion_read_task(AxMinion mod, AislStream s, Context ctx)
{
	int i;
	char str_buf[36 + 1];
	CStuffList lst;

	if (aisl_response(s, AISL_HTTP_OK, AISL_AUTO_LENGTH) != AISL_SUCCESS)
		goto e_reject;

	if (aisl_header(s, "Content-Type", "text/json") == -1)
		goto e_reject;

	/* tasks */
	if (aisl_write(s, "{\"tasks\":[", 10) == -1)
		goto e_reject;

	lst = &mod->tasks;
	for (i = 0; i < lst->length; i++) {
		AxTodoTask task = lst->items[i];
		int rc;

		if (i != 0 && aisl_write(s, ",", 1) == -1)
			goto e_reject;

		uuid_unparse_lower(task->task_id, str_buf);

		if (aisl_printf(s, "\n{\"id\":\"%s\",", str_buf) == -1)
			goto e_reject;

		uuid_unparse_lower(task->list_id, str_buf);
		if (aisl_printf(s, "\"li\":\"%s\",", str_buf) == -1)
			goto e_reject;

		if (aisl_printf(s, "\"x\":%s,", task->is_done ? "true" : "false") == -1)
			goto e_reject;

		rc = aisl_printf(s, "\"p\":\"%c\",", task->priority ? task->priority : '0');
		if (rc == -1)
			goto e_reject;

		if (task->is_done && task->completed) {
			ax_minion_date2str(task->completed, str_buf, sizeof(str_buf));
			if (aisl_printf(s, "\"co\":\"%s\",", str_buf) == -1)
				goto e_reject;
		}

		if (task->created) {
			ax_minion_date2str(task->created, str_buf, sizeof(str_buf));
			if (aisl_printf(s, "\"cr\":\"%s\",", str_buf) == -1)
				goto e_reject;
		}

		rc = aisl_printf(s, "\"t\":\"%s\"}", task->description);
		if (rc == -1)
			goto e_reject;
	}

	/* projects */
	if (aisl_write(s, "\n], \"projects\":[", 16) == -1)
		goto e_reject;

	lst = &mod->projects;
	for (i = 0; i < lst->length; i++) {
		AxTodoProject proj = lst->items[i];
		int rc;

		if (i != 0 && aisl_write(s, ",", 1) == -1)
			goto e_reject;

		uuid_unparse_lower(proj->project_id, str_buf);

		if (aisl_printf(s, "\n{\"id\":\"%s\",", str_buf) == -1)
			goto e_reject;

		if (aisl_printf(s, "\"n\":\"%s\",", proj->name) == -1)
			goto e_reject;

		rc = aisl_printf(s, "\"r\":%"PRIu32"", proj->ref_count);
		if (rc == -1)
			goto e_reject;

		if (proj->last_completed) {
			ax_minion_date2str(proj->last_completed, str_buf, sizeof(str_buf));
			if (aisl_printf(s, ",\"lc\":\"%s\"", str_buf) == -1)
				goto e_reject;
		}

		if (aisl_write(s, "}", 1) == -1)
			goto e_reject;

	}

	/* tags */
	if (aisl_write(s, "\n], \"tags\":[", 12) == -1)
		goto e_reject;

	lst = &mod->tags;
	for (i = 0; i < lst->length; i++) {
		AxTodoTag tag = lst->items[i];
		int rc;

		if (i != 0 && aisl_write(s, ",", 1) == -1)
			goto e_reject;

		uuid_unparse_lower(tag->tag_id, str_buf);

		if (aisl_printf(s, "\n{\"id\":\"%s\",", str_buf) == -1)
			goto e_reject;

		if (aisl_printf(s, "\"n\":\"%s\",", tag->name) == -1)
			goto e_reject;

		rc = aisl_printf(s, "\"r\":%"PRIu32"}", tag->ref_count);
		if (rc == -1)
			goto e_reject;
	}
	if (aisl_write(s, "]}", 2) == -1)
		goto e_reject;

	if (aisl_flush(s) != AISL_SUCCESS)
		goto e_reject;

	return;

e_reject:
	AX_LOG_DEBUG("%s: reject", modName);
	aisl_reject(s);
}


static bool
ax_minion_update_task(AxMinion mod, AislStream s, Context ctx)
{
	AxTodoTask task = NULL;
	char str_uuid[36 + 1];
	int i;

	if (!(ctx->task.description)) {
		AX_LOG_STATE("%s: !description", modName);
		return false;
	}

	if (uuid_compare(ctx->task.list_id, mod->todo.list_id) != 0) {
		AX_LOG_STATE("%s: !list_id", modName);
		return false;
	}

	for (i = 0; i < mod->tasks.length; i++) {
		task = (AxTodoTask) mod->tasks.items[i];
		if (uuid_compare(task->task_id, ctx->task.task_id) == 0)
			break;
		task = NULL;
	}

	if (!task) {
		AX_LOG_STATE("%s: !task_id", modName);
		return false;
	}

	if (!(task->priority = ctx->task.priority))
		task->priority = AX_TODO_ZERO_PRIORITY;
	task->created = ctx->task.created;
	task->completed = ctx->task.completed;

	if ((task->is_done = ctx->task.is_done) && !task->completed) {
		time(&task->completed);
	}

	if (task->description)
		free(task->description);
	task->description = ctx->task.description;
	ctx->task.description = NULL;
	uuid_copy(task->list_id, ctx->task.list_id);

	if (ax_todo_write(&mod->todo, &mod->tasks) != AISL_SUCCESS)
		goto e_system;

	if (aisl_header(s, "Content-Type", "text/json") == -1)
		goto e_reject;

	uuid_unparse_lower(task->list_id, str_uuid);

	if (aisl_printf(s, "{\"id\": \"%s\"}", str_uuid) == -1)
		goto e_reject;

	if (aisl_flush(s) != AISL_SUCCESS)
		goto e_reject;

goto finally;

e_reject:
	aisl_reject(s);
	goto finally;

e_system:
	ax_quick_response(s, AISL_HTTP_INTERNAL_SERVER_ERROR);
	goto finally;

finally:
	return true;
}


static bool
ax_minion_delete_task(AxMinion mod, AislStream s, Context ctx)
{
	AxTodoTask task = NULL;
	char str_uuid[36 + 1];
	int i;

	for (i = 0; i < mod->tasks.length; i++) {
		task = (AxTodoTask) mod->tasks.items[i];
		if (uuid_compare(task->task_id, ctx->task.task_id) == 0) {
			cstuff_list_remove(&mod->tasks, i);
			break;
		}
		task = NULL;
	}

	if (!task) {
		AX_LOG_STATE("%s: !task_id", modName);
		return false;
	}

	uuid_unparse_lower(task->list_id, str_uuid);
	ax_todo_task_free(task);

	if (ax_todo_write(&mod->todo, &mod->tasks) != AISL_SUCCESS)
		goto e_system;

	if (aisl_header(s, "Content-Type", "text/json") == -1)
		goto e_reject;

	if (aisl_printf(s, "{\"id\": \"%s\"}", str_uuid) == -1)
		goto e_reject;

	if (aisl_flush(s) != AISL_SUCCESS)
		goto e_reject;

goto finally;

e_reject:
	aisl_reject(s);
	goto finally;

e_system:
	ax_quick_response(s, AISL_HTTP_INTERNAL_SERVER_ERROR);
	goto finally;

finally:
	return true;
}


static AislStatus
on_stream_request(AxMinion mod, const struct aisl_evt *evt)
{
	Context ctx = aisl_get_context((AislStream)evt->source);
	AislStream s = (AislStream)evt->source;

	/* verify input */
	AX_LOG_STATE("%s: request mode = %d", modName, ctx->mode);
	switch(ctx->mode) {
	case AX_MINION_TODAY:
		if (!ax_minion_today(mod, s, ctx))
			goto bad_request;
		break;

	case AX_MINION_CREATE_TASK:
		if (!ax_minion_create_task(mod, s, ctx))
			goto bad_request;
		break;

	case AX_MINION_READ_TASK:
		ax_minion_read_task(mod, s, ctx);
		break;

	case AX_MINION_UPDATE_TASK:
		if (!ax_minion_update_task(mod, s, ctx))
			goto bad_request;
		break;

	case AX_MINION_DELETE_TASK:
		if (!ax_minion_delete_task(mod, s, ctx))
			goto bad_request;
		break;

	default:
		goto bad_request;
	}

	goto finally;

bad_request:
	ax_quick_response(s, AISL_HTTP_BAD_REQUEST);

finally:
	return AISL_SUCCESS;
}


static AislStatus
on_stream_close(AxMinion mod, const struct aisl_evt *evt)
{
	context_free((Context)aisl_get_context((AislStream)evt->source));
	return AISL_SUCCESS;
}


static AislStatus
ax_minion_on_event(AxMinion mod, const struct aisl_evt *evt)
{
	switch(evt->code) {
	case AISL_EVENT_STREAM_OPEN:
		return on_stream_open(mod, (const struct aisl_evt_open *)evt);

	case AISL_EVENT_STREAM_HEADER:
		return on_stream_header(mod, (const struct aisl_evt_header *)evt);

	case AISL_EVENT_STREAM_INPUT:
		return on_stream_input(mod, (const struct aisl_evt_input *)evt);

	case AISL_EVENT_STREAM_REQUEST:
		return on_stream_request(mod, evt);

	case AISL_EVENT_STREAM_CLOSE:
		return on_stream_close(mod, evt);

	default:
		return AISL_IDLE;
	}
}



AislStatus
ax_minion_init(AxMinion mod, const struct ax_minion_cfg *cfg)
{
	AislStatus result;

	AX_MODULE_INIT(ax_minion, cfg->end_point);

	if ((result = ax_todo_init(&mod->todo, cfg->todo_file)) != AISL_SUCCESS)
		return result;

	if ((cstuff_list_init(&mod->tasks, 32)) != CSTUFF_SUCCESS)
		return AISL_MALLOC_ERROR;

	if ((cstuff_list_init(&mod->projects, 8)) != CSTUFF_SUCCESS)
		return AISL_MALLOC_ERROR;

	if ((cstuff_list_init(&mod->tags, 32)) != CSTUFF_SUCCESS)
		return AISL_MALLOC_ERROR;

	if ((result = ax_todo_read(&mod->todo, &mod->tasks, &mod->projects,
					&mod->tags)) != AISL_SUCCESS)
		return result;

	ax_minion_sort(&mod->tasks, (AxMinionCompare)ax_minion_compare_tasks);
	ax_minion_sort(&mod->projects, (AxMinionCompare)ax_minion_compare_projects);
	ax_minion_sort(&mod->tags, (AxMinionCompare)ax_minion_compare_tags);

	if (ax_todo_write(&mod->todo, &mod->tasks) != AISL_SUCCESS) {
		AX_LOG_DEBUG("Write failed ;(");
	}
	return result;
}


void
ax_minion_release(AxMinion mod)
{
	ax_todo_release(&mod->todo);
	cstuff_list_release(&mod->tasks, (CStuffListFree) ax_todo_task_free);
	cstuff_list_release(&mod->projects, (CStuffListFree) ax_todo_project_free);
	cstuff_list_release(&mod->tags, (CStuffListFree) ax_todo_tag_free);
}