/*
*
*    Gosora Common Resources
*    Copyright Azareal 2018 - 2020
*
 */
package common // import "git.tuxpa.in/a/gosora/common"

import (
	"database/sql"
	"io"
	"log"
	"net"
	"net/http"
	"os"
	"runtime/debug"
	"strconv"
	"strings"
	"sync/atomic"
	"time"

	meta "git.tuxpa.in/a/gosora/common/meta"
	qgen "git.tuxpa.in/a/gosora/query_gen"
)

var SoftwareVersion = Version{Major: 0, Minor: 3, Patch: 0, Tag: "dev"}

var Meta meta.MetaStore

// nolint I don't want to write comments for each of these o.o
const Hour int = 60 * 60
const Day = Hour * 24
const Week = Day * 7
const Month = Day * 30
const Year = Day * 365
const Kilobyte int = 1024
const Megabyte = Kilobyte * 1024
const Gigabyte = Megabyte * 1024
const Terabyte = Gigabyte * 1024
const Petabyte = Terabyte * 1024

var StartTime time.Time
var GzipStartEtag string
var StartEtag string
var TmplPtrMap = make(map[string]interface{})

// Anti-spam token with rotated key
var JSTokenBox atomic.Value              // TODO: Move this and some of these other globals somewhere else
var SessionSigningKeyBox atomic.Value    // For MFA to avoid hitting the database unneccessarily
var OldSessionSigningKeyBox atomic.Value // Just in case we've signed with a key that's about to go stale so we don't annoy the user too much
var IsDBDown int32 = 0                   // 0 = false, 1 = true. this is value which should be manipulated with package atomic for representing whether the database is down so we don't spam the log with lots of redundant errors

// ErrNoRows is an alias of sql.ErrNoRows, just in case we end up with non-database/sql datastores
var ErrNoRows = sql.ErrNoRows

//var StrSlicePool sync.Pool

// ? - Make this more customisable?
/*var ExternalSites = map[string]string{
    "YT": "https://www.youtube.com/",
}*/

// TODO: Make this more customisable
var SpammyDomainBits = []string{"porn", "sex", "acup", "nude", "milf", "tits", "vape", "busty", "kink", "lingerie", "strapon", "problog", "fet", "xblog", "blogin", "blognetwork", "relayblog"}

var Chrome, Firefox int // ! Temporary Hack for http push
var SimpleBots []int    // ! Temporary hack to stop semrush, ahrefs, python bots and other from wasting resources

type StringList []string

// ? - Should we allow users to upload .php or .go files? It could cause security issues. We could store them with a mangled extension to render them inert
// TODO: Let admins manage this from the Control Panel
// apng is commented out for now, as we have no way of re-encoding it into a smaller file
var AllowedFileExts = StringList{
    "png", "jpg", "jpe", "jpeg", "jif", "jfi", "jfif", "svg", "bmp", "gif", "tiff", "tif", "webp", "apng", "avif", "flif", "heif", "heic", "bpg", // images (encodable) + apng (browser support) + bpg + avif + flif + heif / heic

    "txt", "xml", "json", "yaml", "toml", "ini", "md", "html", "rtf", "js", "py", "rb", "css", "scss", "less", "eqcss", "pcss", "java", "ts", "cs", "c", "cc", "cpp", "cxx", "C", "c++", "h", "hh", "hpp", "hxx", "h++", "rs", "rlib", "htaccess", "gitignore", /*"go","php",*/ // text

    "wav", "mp3", "oga", "m4a", "flac", "ac3", "aac", "opus", // audio

    "mp4", "avi", "ogg", "ogv", "ogx", "wmv", "webm", "flv", "f4v", "xvid", "mov", "movie", "qt", // video

    "otf", "woff2", "woff", "ttf", "eot", // fonts

    "bz2", "zip", "zipx", "gz", "7z", "tar", "cab", "rar", "kgb", "pea", "xz", "zz", "tgz", "xpi", // archives

    "docx", "pdf", // documents
}
var ImageFileExts = StringList{
    "png", "jpg", "jpe", "jpeg", "jif", "jfi", "jfif", "svg", "bmp", "gif", "tiff", "tif", "webp", /* "apng", "bpg", "avif", */
}
var TextFileExts = StringList{
    "txt", "xml", "json", "yaml", "toml", "ini", "md", "html", "rtf", "js", "py", "rb", "css", "scss", "less", "eqcss", "pcss", "java", "ts", "cs", "c", "cc", "cpp", "cxx", "C", "c++", "h", "hh", "hpp", "hxx", "h++", "rs", "rlib", "htaccess", "gitignore", /*"go","php",*/
}
var VideoFileExts = StringList{
    "mp4", "avi", "ogg", "ogv", "ogx", "wmv", "webm", "flv", "f4v", "xvid", "mov", "movie", "qt",
}
var WebVideoFileExts = StringList{
    "mp4", "avi", "ogg", "ogv", "webm",
}
var WebAudioFileExts = StringList{
    "wav", "mp3", "oga", "m4a", "flac",
}
var ArchiveFileExts = StringList{
    "bz2", "zip", "zipx", "gz", "7z", "tar", "cab", "rar", "kgb", "pea", "xz", "zz", "tgz", "xpi",
}
var ExecutableFileExts = StringList{
    "exe", "jar", "phar", "shar", "iso", "apk", "deb",
}

func init() {
    JSTokenBox.Store("")
    SessionSigningKeyBox.Store("")
    OldSessionSigningKeyBox.Store("")
}

// TODO: Write a test for this
func (sl StringList) Contains(needle string) bool {
    for _, it := range sl {
        if it == needle {
            return true
        }
    }
    return false
}

/*var DbTables []string
var TableToID = make(map[string]int)
var IDToTable = make(map[int]string)

func InitTables(acc *qgen.Accumulator) error {
    stmt := acc.Select("tables").Columns("id,name").Prepare()
    if e := acc.FirstError(); e != nil {
        return e
    }
    return eachall(stmt, func(r *sql.Rows) error {
        var id int
        var name string
        if e := r.Scan(&id, &name); e != nil {
            return e
        }
        TableToID[name] = id
        IDToTable[id] = name
        return nil
    })
}*/

type dbInits []func(acc *qgen.Accumulator) error

var DbInits dbInits

func (inits dbInits) Run() error {
    for _, i := range inits {
        if e := i(qgen.NewAcc()); e != nil {
            return e
        }
    }
    return nil
}

func (inits dbInits) Add(i ...func(acc *qgen.Accumulator) error) {
    DbInits = dbInits(append(DbInits, i...))
}

// TODO: Add a graceful shutdown function
func StoppedServer(msg ...interface{}) {
    //log.Print("stopped server")
    StopServerChan <- msg
}

var StopServerChan = make(chan []interface{})

var LogWriter = io.MultiWriter(os.Stdout)
var ErrLogWriter = io.MultiWriter(os.Stderr)
var ErrLogger = log.New(os.Stderr, "", log.LstdFlags)

func DebugDetail(args ...interface{}) {
    if Dev.SuperDebug {
        log.Print(args...)
    }
}

func DebugDetailf(str string, args ...interface{}) {
    if Dev.SuperDebug {
        log.Printf(str, args...)
    }
}

func DebugLog(args ...interface{}) {
    if Dev.DebugMode {
        log.Print(args...)
    }
}

func DebugLogf(str string, args ...interface{}) {
    if Dev.DebugMode {
        log.Printf(str, args...)
    }
}

func Log(args ...interface{}) {
    log.Print(args...)
}
func Logf(str string, args ...interface{}) {
    log.Printf(str, args...)
}
func Err(args ...interface{}) {
    ErrLogger.Print(args...)
}

func Count(stmt *sql.Stmt) (count int) {
    e := stmt.QueryRow().Scan(&count)
    if e != nil {
        LogError(e)
    }
    return count
}
func Countf(stmt *sql.Stmt, args ...interface{}) (count int) {
    e := stmt.QueryRow(args...).Scan(&count)
    if e != nil {
        LogError(e)
    }
    return count
}
func Createf(stmt *sql.Stmt, args ...interface{}) (id int, e error) {
    res, e := stmt.Exec(args...)
    if e != nil {
        return 0, e
    }
    id64, e := res.LastInsertId()
    return int(id64), e
}

func eachall(stmt *sql.Stmt, f func(r *sql.Rows) error) error {
    rows, e := stmt.Query()
    if e != nil {
        return e
    }
    defer rows.Close()
    for rows.Next() {
        if e := f(rows); e != nil {
            return e
        }
    }
    return rows.Err()
}

var qcache = []string{0: "?", 1: "?,?", 2: "?,?,?", 3: "?,?,?,?", 4: "?,?,?,?,?", 5: "?,?,?,?,?,?", 6: "?,?,?,?,?,?,?", 7: "?,?,?,?,?,?,?,?", 8: "?,?,?,?,?,?,?,?,?"}

func inqbuild(ids []int) ([]interface{}, string) {
    if len(ids) < 8 {
        idList := make([]interface{}, len(ids))
        for i, id := range ids {
            idList[i] = strconv.Itoa(id)
        }
        return idList, qcache[len(ids)-1]
    }

    var sb strings.Builder
    sb.Grow((len(ids) * 2) - 1)
    idList := make([]interface{}, len(ids))
    for i, id := range ids {
        idList[i] = strconv.Itoa(id)
        if i == 0 {
            sb.WriteRune('?')
        } else {
            sb.WriteString(",?")
        }
    }
    return idList, sb.String()
}

func inqbuild2(count int) string {
    if count <= 8 {
        return qcache[count-1]
    }
    var sb strings.Builder
    sb.Grow((count * 2) - 1)
    for i := 0; i < count; i++ {
        if i == 0 {
            sb.WriteRune('?')
        } else {
            sb.WriteString(",?")
        }
    }
    return sb.String()
}

func inqbuildstr(strs []string) ([]interface{}, string) {
    if len(strs) < 8 {
        idList := make([]interface{}, len(strs))
        for i, id := range strs {
            idList[i] = id
        }
        return idList, qcache[len(strs)-1]
    }

    var sb strings.Builder
    sb.Grow((len(strs) * 2) - 1)
    idList := make([]interface{}, len(strs))
    for i, id := range strs {
        idList[i] = id
        if i == 0 {
            sb.WriteRune('?')
        } else {
            sb.WriteString(",?")
        }
    }
    return idList, sb.String()
}

var ConnWatch = &ConnWatcher{}

type ConnWatcher struct {
    n int64
}

func (cw *ConnWatcher) StateChange(conn net.Conn, state http.ConnState) {
    switch state {
    case http.StateNew:
        atomic.AddInt64(&cw.n, 1)
    case http.StateHijacked, http.StateClosed:
        atomic.AddInt64(&cw.n, -1)
    }
}

func (cw *ConnWatcher) Count() int {
    return int(atomic.LoadInt64(&cw.n))
}

func EatPanics() {
    if r := recover(); r != nil {
        log.Print(r)
        debug.PrintStack()
        log.Fatal("Fatal error.")
    }
}