package hn

import (
	"net/http"
	"time"

	u "git.eeqj.de/sneak/goutil"
	"github.com/flosch/pongo2"
	"github.com/jinzhu/gorm"
	"github.com/labstack/echo"
)

// RequestHandlerSet holds the dependencies shared by the HTTP handlers.
type RequestHandlerSet struct {
	db      *gorm.DB
	version string
}

// NewRequestHandlerSet builds a RequestHandlerSet for the given version and
// database handle.
func NewRequestHandlerSet(version string, db *gorm.DB) *RequestHandlerSet {
	rhs := new(RequestHandlerSet)
	rhs.db = db
	rhs.version = version

	return rhs
}

// exitRow is a story that has left the front page within the last 24h.
type exitRow struct {
	Duration     string
	DurationSecs uint
	URL          string
	Title        string
	HighestRank  uint
	HNID         uint
	Score        uint
	TimeGone     string
	TimeGoneSecs uint
}

// currentRow is a story currently on the front page.
type currentRow struct {
	Duration     string
	DurationSecs uint
	URL          string
	Title        string
	Score        uint
	HighestRank  uint
	HNID         uint
	Rank         uint
}

// exitedRows returns the stories that left the front page in the last 24h,
// most recently departed first.
func (r *RequestHandlerSet) exitedRows() []exitRow {
	last24h := time.Now().Add(time.Second * 86400 * -1)

	var fpi []HNFrontPage
	r.db.Where("disappeared is not ? and disappeared > ?", time.Time{}, last24h).Order("disappeared desc").Find(&fpi)

	rows := make([]exitRow, 0, len(fpi))
	for _, item := range fpi {
		rows = append(rows, exitRow{
			Duration:     u.TimeDiffHuman(item.Disappeared, item.Appeared),
			DurationSecs: u.TimeDiffAbsSeconds(item.Disappeared, item.Appeared),
			URL:          item.URL,
			HNID:         item.HNID,
			Score:        item.Score,
			Title:        item.Title,
			HighestRank:  item.HighestRank,
			TimeGone:     u.TimeDiffHuman(time.Now(), item.Disappeared),
			TimeGoneSecs: u.TimeDiffAbsSeconds(time.Now(), item.Disappeared),
		})
	}

	return rows
}

// currentRows returns the stories currently on the front page, best rank first.
func (r *RequestHandlerSet) currentRows() []currentRow {
	var cur []HNFrontPage
	r.db.Where("disappeared is ?", time.Time{}).Order("rank asc").Find(&cur)

	rows := make([]currentRow, 0, len(cur))
	for _, item := range cur {
		rows = append(rows, currentRow{
			Duration:     u.TimeDiffHuman(time.Now(), item.Appeared),
			DurationSecs: u.TimeDiffAbsSeconds(time.Now(), item.Appeared),
			URL:          item.URL,
			HNID:         item.HNID,
			Score:        item.Score,
			Title:        item.Title,
			HighestRank:  item.HighestRank,
			Rank:         item.Rank,
		})
	}

	return rows
}

func (r *RequestHandlerSet) indexHandler(c echo.Context) error {
	tc := pongo2.Context{
		"time":    time.Now().UTC().Format(time.RFC3339Nano),
		"exits":   r.exitedRows(),
		"current": r.currentRows(),
		"gitrev":  r.version,
	}

	return c.Render(http.StatusOK, "index.html", tc)
}

func (r *RequestHandlerSet) aboutHandler(c echo.Context) error {
	tc := pongo2.Context{
		"time":   time.Now().UTC().Format(time.RFC3339Nano),
		"gitrev": r.version,
	}

	return c.Render(http.StatusOK, "about.html", tc)
}