// Copyright 2019 Drone.IO Inc. All rights reserved.
// Use of this source code is governed by the Polyform License
// that can be found in the LICENSE file.

// Package handler provides HTTP handlers that expose pipeline
// state and status.
package handler

import (
	"net/http"
	"sort"
	"strconv"

	"git.awesome-for.me/liuzhiguo/drone-go/drone"
	hook "git.awesome-for.me/liuzhiguo/runner-go/logger/history"
	"git.awesome-for.me/liuzhiguo/runner-go/pipeline/reporter/history"
)

// HandleHealth returns a http.HandlerFunc that returns a 200
// if the service is healthly.
func HandleHealth(t *history.History) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		// TODO(bradrydzewski) iterate through the list of
		// pending or running stages and write an error message
		// if the timeout is exceeded.
		nocache(w)
		w.WriteHeader(200)
	}
}

// HandleIndex returns a http.HandlerFunc that displays a list
// of currently and previously executed builds.
func HandleIndex(t *history.History) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		d := t.Entries()

		s1 := history.ByTimestamp(d)
		s2 := history.ByStatus(d)
		sort.Sort(s1)
		sort.Sort(s2)

		if r.Header.Get("Accept") == "application/json" {
			nocache(w)
			renderJSON(w, d)
		} else {
			nocache(w)
			render(w, "index.tmpl", &data{Items: d})
		}
	}
}

// HandleStage returns a http.HandlerFunc that displays the
// stage details.
func HandleStage(hist *history.History, logger *hook.Hook) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		id, _ := strconv.ParseInt(r.FormValue("id"), 10, 64)

		// filter logs by stage id.
		logs := logger.Filter(func(entry *hook.Entry) bool {
			return entry.Data["stage.id"] == id
		})

		// find pipeline by stage id
		entry := hist.Entry(id)
		if entry == nil {
			w.WriteHeader(404)
			return
		}

		nocache(w)
		render(w, "stage.tmpl", struct {
			*history.Entry
			Logs []*hook.Entry
		}{
			Entry: entry,
			Logs:  logs,
		})
	}
}

// HandleLogHistory returns a http.HandlerFunc that displays a
// list recent log entries.
func HandleLogHistory(t *hook.Hook) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		nocache(w)
		render(w, "logs.tmpl", struct {
			Entries []*hook.Entry
		}{t.Entries()})
	}
}

// data is a template data structure that provides helper
// functions for calculating the system state.
type data struct {
	Items []*history.Entry
}

// helper function returns true if no running builds exists.
func (d *data) Idle() bool {
	for _, item := range d.Items {
		switch item.Stage.Status {
		case drone.StatusPending, drone.StatusRunning:
			return false
		}
	}
	return true
}