package main

import (
	"log"
	"os"
	"time"

	"github.com/jmoiron/sqlx"
	_ "github.com/mattn/go-sqlite3"
)

const schema = `
CREATE TABLE IF NOT EXISTS entries (
	id INTEGER PRIMARY KEY,
	location TEXT NOT NULL,
	referrer TEXT,
	started_at DATETIME NOT NULL,
	time_spent INTEGER NOT NULL,
	scrolled_to REAL NOT NULL
);`

type Entry struct {
	Id         int       `json:"-" db:"id"`
	Location   string    `json:"location" db:"location"`
	Referrer   string    `json:"referrer,omitempty" db:"referrer"`
	StartedAt  time.Time `json:"startedAt" db:"started_at"`
	TimeSpent  int       `json:"timeSpent" db:"time_spent"`
	ScrolledTo float32   `json:"scrolledTo" db:"scrolled_to"`
}

var db *sqlx.DB

func InitEntries() {
	file := os.Getenv("STATSDB")
	if file == "" {
		log.Println("Defaulting to STATSDB=./stats.db")
		file = "./stats.db"
	}
	var err error
	db, err = sqlx.Connect("sqlite3", file)
	if err != nil {
		log.Fatalln(err)
	}
	_, err = db.Exec(schema)
	if err != nil {
		log.Fatalln("Could not initialize schema")
		log.Fatalln(err)
	}
}

func CloseEntries() {
	db.Close()
}

func InsertEntry(entry *Entry) error {
	const query = `
	INSERT INTO entries (location, referrer, started_at, time_spent, scrolled_to)
	VALUES (:location, :referrer, :started_at, :time_spent, :scrolled_to);`
	_, err := db.NamedExec(query, entry)
	log.Println("Entry recorded:", entry.Location)
	return err
}

func CountEntries() (count uint, err error) {
	err = db.Get(&count, "SELECT COUNT(*) FROM entries;")
	return
}

func AllEntries() (entries []Entry, err error) {
	err = db.Select(&entries, "SELECT * FROM entries;")
	return
}

func ListEntries(from, count uint) (entries []Entry, err error) {
	err = db.Select(&entries, "SELECT * FROM entries LIMIT ? OFFSET ?;", count, from)
	return
}

func EntriesSince(since time.Time) (entries []Entry, err error) {
	err = db.Select(&entries, "SELECT * FROM entries WHERE started_at > ?;", since)
	return
}

func FirstEntry() (entry Entry, err error) {
	err = db.Get(&entry, "SELECT * FROM entries ORDER BY started_at ASC LIMIT 1;")
	return
}