package command

import (
	"fmt"
	"net/url"
	"strings"

	"github.com/hashicorp/nomad/api/contexts"
	"github.com/posener/complete"
	"github.com/skratchdot/open-golang/open"
)

var (
	// uiContexts is the contexts the ui can open automatically.
	uiContexts = []contexts.Context{contexts.Jobs, contexts.Allocs, contexts.Nodes}
)

type UiCommand struct {
	Meta
}

func (c *UiCommand) Help() string {
	helpText := `
Usage: nomad ui [options] <identifier>

Open the Nomad Web UI in the default browser. An optional identifier may be
provided, in which case the UI will be opened to view the details for that
object. Supported identifiers are jobs, allocations and nodes.

General Options:

  ` + generalOptionsUsage()

	return strings.TrimSpace(helpText)
}

func (c *UiCommand) AutocompleteFlags() complete.Flags {
	return c.Meta.AutocompleteFlags(FlagSetClient)
}

func (c *UiCommand) AutocompleteArgs() complete.Predictor {
	return complete.PredictFunc(func(a complete.Args) []string {
		client, err := c.Meta.Client()
		if err != nil {
			return nil
		}

		resp, _, err := client.Search().PrefixSearch(a.Last, contexts.All, nil)
		if err != nil {
			return []string{}
		}

		final := make([]string, 0)

		for _, allowed := range uiContexts {
			matches, ok := resp.Matches[allowed]
			if !ok {
				continue
			}
			if len(matches) == 0 {
				continue
			}

			final = append(final, matches...)
		}

		return final
	})
}

func (c *UiCommand) Synopsis() string {
	return "Open the Nomad Web UI"
}

func (c *UiCommand) Name() string { return "ui" }

func (c *UiCommand) Run(args []string) int {
	flags := c.Meta.FlagSet(c.Name(), FlagSetClient)
	flags.Usage = func() { c.Ui.Output(c.Help()) }

	if err := flags.Parse(args); err != nil {
		return 1
	}

	// Check that we got no more than one argument
	args = flags.Args()
	if l := len(args); l > 1 {
		c.Ui.Error("This command takes no or one optional argument, [<identifier>]")
		c.Ui.Error(commandErrorText(c))
		return 1
	}

	// Get the HTTP client
	client, err := c.Meta.Client()
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error initializing client: %s", err))
		return 1
	}

	url, err := url.Parse(client.Address())
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error parsing Nomad address %q: %s", client.Address(), err))
		return 1
	}

	// We were given an id so look it up
	if len(args) == 1 {
		id := args[0]

		// Query for the context associated with the id
		res, _, err := client.Search().PrefixSearch(id, contexts.All, nil)
		if err != nil {
			c.Ui.Error(fmt.Sprintf("Error querying search with id: %q", err))
			return 1
		}

		if res.Matches == nil {
			c.Ui.Error(fmt.Sprintf("No matches returned for query: %q", err))
			return 1
		}

		var match contexts.Context
		var fullID string
		matchCount := 0
		for _, ctx := range uiContexts {
			vers, ok := res.Matches[ctx]
			if !ok {
				continue
			}

			if l := len(vers); l == 1 {
				match = ctx
				fullID = vers[0]
				matchCount++
			} else if l > 0 && vers[0] == id {
				// Exact match
				match = ctx
				fullID = vers[0]
				break
			}

			// Only a single result should return, as this is a match against a full id
			if matchCount > 1 || len(vers) > 1 {
				c.logMultiMatchError(id, res.Matches)
				return 1
			}
		}

		switch match {
		case contexts.Nodes:
			url.Path = fmt.Sprintf("ui/clients/%s", fullID)
		case contexts.Allocs:
			url.Path = fmt.Sprintf("ui/allocations/%s", fullID)
		case contexts.Jobs:
			url.Path = fmt.Sprintf("ui/jobs/%s", fullID)
		default:
			c.Ui.Error(fmt.Sprintf("Unable to resolve ID: %q", id))
			return 1
		}
	}

	c.Ui.Output(fmt.Sprintf("Opening URL %q", url.String()))
	if err := open.Start(url.String()); err != nil {
		c.Ui.Error(fmt.Sprintf("Error opening URL: %s", err))
		return 1
	}

	return 0
}

// logMultiMatchError is used to log an error message when multiple matches are
// found. The error message logged displays the matched IDs per context.
func (c *UiCommand) logMultiMatchError(id string, matches map[contexts.Context][]string) {
	c.Ui.Error(fmt.Sprintf("Multiple matches found for id %q", id))
	for _, ctx := range uiContexts {
		vers, ok := matches[ctx]
		if !ok {
			continue
		}
		if len(vers) == 0 {
			continue
		}

		c.Ui.Error(fmt.Sprintf("\n%s:", strings.Title(string(ctx))))
		c.Ui.Error(fmt.Sprintf("%s", strings.Join(vers, ", ")))
	}
}