package datadog

import (
	"time"
)

const logsListPath = "/v1/logs-queries/list"

// LogsListRequest represents the request body sent to the list API
type LogsListRequest struct {
	Index   *string                   `json:"index,omitempty"`
	Limit   *int                      `json:"limit,omitempty"`
	Query   *string                   `json:"query"`
	Sort    *string                   `json:"sort,omitempty"`
	StartAt *string                   `json:"startAt,omitempty"`
	Time    *LogsListRequestQueryTime `json:"time"`
}

// LogsListRequestQueryTime represents the time object for the request sent to the list API
type LogsListRequestQueryTime struct {
	TimeFrom *string `json:"from"`
	TimeTo   *string `json:"to"`
	TimeZone *string `json:"timezone,omitempty"`
	Offset   *int    `json:"offset,omitempty"`
}

// LogsList represents the base API response returned by the list API
type LogsList struct {
	Logs      []Logs  `json:"logs"`
	NextLogID *string `json:"nextLogId"`
	Status    *string `json:"status"`
}

func (l *LogsList) next() bool {
	if l.NextLogID != nil {
		return true
	}

	return false
}

// Logs represents the data of a log entry and contains the UUID of that entry (which
// is used for the StartAt option in an API request) as well as the content of that log
type Logs struct {
	ID      *string     `json:"id"`
	Content LogsContent `json:"content"`
}

// LogsContent respresents the actual log content returned by the list API
type LogsContent struct {
	Timestamp  *time.Time     `json:"timestamp"`
	Tags       []string       `json:"tags,omitempty"`
	Attributes LogsAttributes `json:"attributes,omitempty"`
	Host       *string        `json:"host"`
	Service    *string        `json:"service"`
	Message    *string        `json:"message"`
}

// LogsAttributes represents the Content attribute object from the list API
type LogsAttributes map[string]interface{}

// GetLogsList gets a page of log entries based on the values in the provided LogListRequest
func (client *Client) GetLogsList(logsRequest *LogsListRequest) (logsList *LogsList, err error) {
	out := &LogsList{}

	if err = client.doJsonRequest("POST", logsListPath, logsRequest, out); err != nil {
		return nil, err
	}

	return out, nil
}

// GetLogsListPages calls GetLogsList and handles the pagination performed by the 'logs-queries/list' API
func (client *Client) GetLogsListPages(logsRequest *LogsListRequest, maxResults int) (logs []Logs, err error) {

	// Reduce the number of results we have to fetch if the limit in our request body is greater than the value of maxResults
	if maxResults < logsRequest.GetLimit() && maxResults > 0 {
		logsRequest.SetLimit(maxResults)
	}

	response, err := client.GetLogsList(logsRequest)
	if err != nil {
		return nil, err
	}

	logs = append(logs, response.Logs...)
	if maxResults < 0 { // Retrieve all results
		for response.next() && err == nil {
			logsRequest.StartAt = response.NextLogID
			response, err = client.GetLogsList(logsRequest)
			if err != nil {
				return logs, err
			}

			logs = append(logs, response.Logs...)
		}
	} else {
		for response.next() && err == nil && len(logs) < maxResults {
			logsRequest.StartAt = response.NextLogID

			if maxResults-len(logs) < logsRequest.GetLimit() {
				logsRequest.SetLimit(maxResults - len(logs))
			}

			response, err = client.GetLogsList(logsRequest)
			if err != nil {
				return logs, err
			}

			logs = append(logs, response.Logs...)
		}
	}
	return logs, err
}