package main

import (
	"fmt"
	"net/http"
	"strconv"

	"github.com/gofrs/uuid"
	"github.com/knadh/listmonk/models"
	"github.com/lib/pq"

	"github.com/labstack/echo"
)

type listsWrap struct {
	Results []models.List `json:"results"`

	Total   int `json:"total"`
	PerPage int `json:"per_page"`
	Page    int `json:"page"`
}

var (
	listQuerySortFields = []string{"name", "type", "subscriber_count", "created_at", "updated_at"}
)

// handleGetLists retrieves lists with additional metadata like subscriber counts. This may be slow.
func handleGetLists(c echo.Context) error {
	var (
		app = c.Get("app").(*App)
		out listsWrap

		pg         = getPagination(c.QueryParams(), 20)
		orderBy    = c.FormValue("order_by")
		order      = c.FormValue("order")
		minimal, _ = strconv.ParseBool(c.FormValue("minimal"))
		listID, _  = strconv.Atoi(c.Param("id"))
		single     = false
	)

	// Fetch one list.
	if listID > 0 {
		single = true
	}

	if !single && minimal {
		// Minimal query simply returns the list of all lists with no additional metadata. This is fast.
		if err := app.queries.GetLists.Select(&out.Results, ""); err != nil {
			app.log.Printf("error fetching lists: %v", err)
			return echo.NewHTTPError(http.StatusInternalServerError,
				app.i18n.Ts("globals.messages.errorFetching",
					"name", "{globals.terms.lists}", "error", pqErrMsg(err)))
		}
		if len(out.Results) == 0 {
			return c.JSON(http.StatusOK, okResp{[]struct{}{}})
		}

		// Meta.
		out.Total = out.Results[0].Total
		out.Page = 1
		out.PerPage = out.Total
		if out.PerPage == 0 {
			out.PerPage = out.Total
		}
		return c.JSON(http.StatusOK, okResp{out})
	}

	// Sort params.
	if !strSliceContains(orderBy, listQuerySortFields) {
		orderBy = "created_at"
	}
	if order != sortAsc && order != sortDesc {
		order = sortAsc
	}

	if err := db.Select(&out.Results, fmt.Sprintf(app.queries.QueryLists, orderBy, order), listID, pg.Offset, pg.Limit); err != nil {
		app.log.Printf("error fetching lists: %v", err)
		return echo.NewHTTPError(http.StatusInternalServerError,
			app.i18n.Ts("globals.messages.errorFetching",
				"name", "{globals.terms.lists}", "error", pqErrMsg(err)))
	}
	if single && len(out.Results) == 0 {
		return echo.NewHTTPError(http.StatusBadRequest,
			app.i18n.Ts("globals.messages.notFound", "name", "{globals.terms.list}"))
	}
	if len(out.Results) == 0 {
		return c.JSON(http.StatusOK, okResp{[]struct{}{}})
	}

	// Replace null tags.
	for i, v := range out.Results {
		if v.Tags == nil {
			out.Results[i].Tags = make(pq.StringArray, 0)
		}
	}

	if single {
		return c.JSON(http.StatusOK, okResp{out.Results[0]})
	}

	// Meta.
	out.Total = out.Results[0].Total
	out.Page = pg.Page
	out.PerPage = pg.PerPage
	if out.PerPage == 0 {
		out.PerPage = out.Total
	}

	return c.JSON(http.StatusOK, okResp{out})
}

// handleCreateList handles list creation.
func handleCreateList(c echo.Context) error {
	var (
		app = c.Get("app").(*App)
		o   = models.List{}
	)

	if err := c.Bind(&o); err != nil {
		return err
	}

	// Validate.
	if !strHasLen(o.Name, 1, stdInputMaxLen) {
		return echo.NewHTTPError(http.StatusBadRequest, app.i18n.T("lists.invalidName"))
	}

	uu, err := uuid.NewV4()
	if err != nil {
		app.log.Printf("error generating UUID: %v", err)
		return echo.NewHTTPError(http.StatusInternalServerError,
			app.i18n.Ts("globals.messages.errorUUID", "error", err.Error()))
	}

	// Insert and read ID.
	var newID int
	o.UUID = uu.String()
	if err := app.queries.CreateList.Get(&newID,
		o.UUID,
		o.Name,
		o.Type,
		o.Optin,
		pq.StringArray(normalizeTags(o.Tags))); err != nil {
		app.log.Printf("error creating list: %v", err)
		return echo.NewHTTPError(http.StatusInternalServerError,
			app.i18n.Ts("globals.messages.errorCreating",
				"name", "{globals.terms.list}", "error", pqErrMsg(err)))
	}

	// Hand over to the GET handler to return the last insertion.
	return handleGetLists(copyEchoCtx(c, map[string]string{
		"id": fmt.Sprintf("%d", newID),
	}))
}

// handleUpdateList handles list modification.
func handleUpdateList(c echo.Context) error {
	var (
		app   = c.Get("app").(*App)
		id, _ = strconv.Atoi(c.Param("id"))
	)

	if id < 1 {
		return echo.NewHTTPError(http.StatusBadRequest, app.i18n.T("globals.messages.invalidID"))
	}

	// Incoming params.
	var o models.List
	if err := c.Bind(&o); err != nil {
		return err
	}

	res, err := app.queries.UpdateList.Exec(id,
		o.Name, o.Type, o.Optin, pq.StringArray(normalizeTags(o.Tags)))
	if err != nil {
		app.log.Printf("error updating list: %v", err)
		return echo.NewHTTPError(http.StatusInternalServerError,
			app.i18n.Ts("globals.messages.errorUpdating",
				"name", "{globals.terms.list}", "error", pqErrMsg(err)))
	}

	if n, _ := res.RowsAffected(); n == 0 {
		return echo.NewHTTPError(http.StatusBadRequest,
			app.i18n.Ts("globals.messages.notFound", "name", "{globals.terms.list}"))
	}

	return handleGetLists(c)
}

// handleDeleteLists handles list deletion, either a single one (ID in the URI), or a list.
func handleDeleteLists(c echo.Context) error {
	var (
		app   = c.Get("app").(*App)
		id, _ = strconv.ParseInt(c.Param("id"), 10, 64)
		ids   pq.Int64Array
	)

	if id < 1 && len(ids) == 0 {
		return echo.NewHTTPError(http.StatusBadRequest, app.i18n.T("globals.messages.invalidID"))
	}

	if id > 0 {
		ids = append(ids, id)
	}

	if _, err := app.queries.DeleteLists.Exec(ids); err != nil {
		app.log.Printf("error deleting lists: %v", err)
		return echo.NewHTTPError(http.StatusInternalServerError,
			app.i18n.Ts("globals.messages.errorDeleting",
				"name", "{globals.terms.list}", "error", pqErrMsg(err)))
	}

	return c.JSON(http.StatusOK, okResp{true})
}