package handlers

import (
	"database/sql"
	"fmt"
	"net/http"
	"strconv"
	"time"

	"synlotto-website/helpers"
	"synlotto-website/storage"
)

func SyndicateInviteHandler(db *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		userID, ok := helpers.GetCurrentUserID(r)
		if !ok {
			helpers.RenderError(w, r, http.StatusForbidden)
			return
		}

		switch r.Method {
		case http.MethodGet:
			syndicateID := helpers.Atoi(r.URL.Query().Get("id"))
			data := BuildTemplateData(db, w, r)
			context := helpers.TemplateContext(w, r, data)
			context["SyndicateID"] = syndicateID

			tmpl := helpers.LoadTemplateFiles("invite-syndicate.html", "templates/syndicate/invite.html")
			err := tmpl.ExecuteTemplate(w, "layout", context)
			if err != nil {
				helpers.RenderError(w, r, 500)
			}
		case http.MethodPost:
			syndicateID := helpers.Atoi(r.FormValue("syndicate_id"))
			username := r.FormValue("username")

			err := storage.InviteToSyndicate(db, userID, syndicateID, username)
			if err != nil {
				helpers.SetFlash(w, r, "Failed to send invite: "+err.Error())
			} else {
				helpers.SetFlash(w, r, "Invite sent successfully.")
			}
			http.Redirect(w, r, "/syndicate/view?id="+strconv.Itoa(syndicateID), http.StatusSeeOther)

		default:
			helpers.RenderError(w, r, http.StatusMethodNotAllowed)
		}
	}
}

func ViewInvitesHandler(db *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		userID, ok := helpers.GetCurrentUserID(r)
		if !ok {
			helpers.RenderError(w, r, 403)
			return
		}

		invites := storage.GetPendingInvites(db, userID)
		data := BuildTemplateData(db, w, r)
		context := helpers.TemplateContext(w, r, data)
		context["Invites"] = invites

		tmpl := helpers.LoadTemplateFiles("invites.html", "templates/syndicate/invites.html")
		tmpl.ExecuteTemplate(w, "layout", context)
	}
}

func AcceptInviteHandler(db *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		inviteID := helpers.Atoi(r.URL.Query().Get("id"))
		userID, ok := helpers.GetCurrentUserID(r)
		if !ok {
			helpers.RenderError(w, r, 403)
			return
		}
		err := storage.AcceptInvite(db, inviteID, userID)
		if err != nil {
			helpers.SetFlash(w, r, "Failed to accept invite")
		} else {
			helpers.SetFlash(w, r, "You have joined the syndicate")
		}
		http.Redirect(w, r, "/syndicate", http.StatusSeeOther)
	}
}

func DeclineInviteHandler(db *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		inviteID := helpers.Atoi(r.URL.Query().Get("id"))
		_ = storage.UpdateInviteStatus(db, inviteID, "declined")
		http.Redirect(w, r, "/syndicate/invites", http.StatusSeeOther)
	}
}

func CreateInviteToken(db *sql.DB, syndicateID, invitedByID int, ttlHours int) (string, error) {
	token, err := helpers.GenerateSecureToken()
	if err != nil {
		return "", err
	}

	expires := time.Now().Add(time.Duration(ttlHours) * time.Hour)

	_, err = db.Exec(`
		INSERT INTO syndicate_invite_tokens (syndicate_id, token, invited_by_user_id, expires_at)
		VALUES (?, ?, ?, ?)
	`, syndicateID, token, invitedByID, expires)

	return token, err
}

func AcceptInviteToken(db *sql.DB, token string, userID int) error {
	var syndicateID int
	var expiresAt, acceptedAt sql.NullTime
	err := db.QueryRow(`
	  SELECT syndicate_id, expires_at, accepted_at
	  FROM syndicate_invite_tokens
	  WHERE token = ?
	`, token).Scan(&syndicateID, &expiresAt, &acceptedAt)
	if err != nil {
		return fmt.Errorf("invalid or expired token")
	}
	if acceptedAt.Valid || expiresAt.Time.Before(time.Now()) {
		return fmt.Errorf("token already used or expired")
	}

	_, err = db.Exec(`
	  INSERT INTO syndicate_members (syndicate_id, user_id, role, status, joined_at)
	  VALUES (?, ?, 'member', 'active', CURRENT_TIMESTAMP)
	`, syndicateID, userID)
	if err != nil {
		return err
	}

	_, err = db.Exec(`
	  UPDATE syndicate_invite_tokens
	  SET accepted_by_user_id = ?, accepted_at = CURRENT_TIMESTAMP
	  WHERE token = ?
	`, userID, token)
	return err
}

func GenerateInviteLinkHandler(db *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		userID, ok := helpers.GetCurrentUserID(r)
		if !ok {
			helpers.RenderError(w, r, http.StatusForbidden)
			return
		}

		syndicateID := helpers.Atoi(r.URL.Query().Get("id"))
		token, err := CreateInviteToken(db, syndicateID, userID, 48) // token valid for 48 hours
		if err != nil {
			helpers.SetFlash(w, r, "Failed to generate invite link.")
			http.Redirect(w, r, "/syndicate/view?id="+strconv.Itoa(syndicateID), http.StatusSeeOther)
			return
		}

		origin := r.Host
		if r.TLS != nil {
			origin = "https://" + origin
		} else {
			origin = "http://" + origin
		}
		inviteLink := fmt.Sprintf("%s/syndicate/join?token=%s", origin, token)

		helpers.SetFlash(w, r, "Invite link created: "+inviteLink)
		http.Redirect(w, r, "/syndicate/view?id="+strconv.Itoa(syndicateID), http.StatusSeeOther)
	}
}

func JoinSyndicateWithTokenHandler(db *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		userID, ok := helpers.GetCurrentUserID(r)
		if !ok {
			helpers.RenderError(w, r, http.StatusForbidden)
			return
		}

		token := r.URL.Query().Get("token")
		if token == "" {
			helpers.SetFlash(w, r, "Invalid or missing invite token.")
			http.Redirect(w, r, "/syndicate", http.StatusSeeOther)
			return
		}

		err := AcceptInviteToken(db, token, userID)
		if err != nil {
			helpers.SetFlash(w, r, "Failed to join syndicate: "+err.Error())
		} else {
			helpers.SetFlash(w, r, "You have joined the syndicate!")
		}
		http.Redirect(w, r, "/syndicate", http.StatusSeeOther)
	}
}

func ManageInviteTokensHandler(db *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		userID, ok := helpers.GetCurrentUserID(r)
		if !ok {
			helpers.RenderError(w, r, 403)
			return
		}

		syndicateID := helpers.Atoi(r.URL.Query().Get("id"))

		if !storage.IsSyndicateManager(db, syndicateID, userID) {
			helpers.RenderError(w, r, 403)
			return
		}

		tokens := storage.GetInviteTokensForSyndicate(db, syndicateID)

		data := BuildTemplateData(db, w, r)
		context := helpers.TemplateContext(w, r, data)
		context["Tokens"] = tokens
		context["SyndicateID"] = syndicateID

		tmpl := helpers.LoadTemplateFiles("invite-links.html", "templates/syndicate/invite_links.html")
		tmpl.ExecuteTemplate(w, "layout", context)
	}
}