package routes

import (
	"database/sql"
	"errors"
	"net/http"

	"git.red-panda.pet/pandaware/house/backend/db"
	"git.red-panda.pet/pandaware/house/backend/middleware"
	"git.red-panda.pet/pandaware/house/backend/router"
)

func init() {
	routes["GET"]["/user/{id}/tasks"] = new(UserTasks)
}

type userTasksResponse struct {
	Tasks          []db.Task         `json:"tasks"`
	TaskCategories []db.TaskCategory `json:"task_categories"`
	Categories     []db.Category     `json:"categories"`
}

type UserTasks struct{}

// Authorize implements router.AuthorizedRoute.
func (u *UserTasks) Authorize(ctx *router.Context) error {
	return middleware.Authenticated(ctx)
}

// ValidateParams implements router.ValidatedParamRoute.
func (u *UserTasks) ValidateParams(ctx *router.Context) error {
	if ctx.Parameter("id") == "me" {
		return nil
	}
	return middleware.ValidateUUIDParam(ctx, "id")
}

// Handle implements router.Route.
func (u *UserTasks) Handle(ctx *router.Context) error {
	user := middleware.User(u, ctx)
	id := ctx.Parameter("id")

	if id == "me" {
		id = user.ID
	}

	tx, err := ctx.DB.BeginTx(ctx, &sql.TxOptions{
		ReadOnly: true,
	})

	query := ctx.Query.WithTx(tx)

	if err != nil {
		return ctx.GenericError(err, http.StatusInternalServerError)
	}

	tasks, err := query.TasksForUser(ctx, id)

	if err != nil && !errors.Is(err, sql.ErrNoRows) {
		return ctx.GenericError(err, http.StatusInternalServerError)
	}

	taskIDs := make([]int64, len(tasks))
	for i, task := range tasks {
		taskIDs[i] = task.ID
	}

	taskCategories, err := query.TaskCategoriesOf(ctx, taskIDs)
	if err != nil {
		return ctx.GenericError(err, http.StatusInternalServerError)
	}

	categories, err := query.CategoriesOf(ctx, taskIDs)
	if err != nil && !errors.Is(err, sql.ErrNoRows) {
		return ctx.GenericError(err, http.StatusInternalServerError)
	}

	err = tx.Commit()
	if err != nil {
		return ctx.GenericError(err, http.StatusInternalServerError)
	}

	return ctx.JSON(200, userTasksResponse{
		Tasks:          append([]db.Task{}, tasks...),
		TaskCategories: append([]db.TaskCategory{}, taskCategories...),
		Categories:     append([]db.Category{}, categories...),
	})
}

var _ router.AuthorizedRoute = new(UserTasks)
var _ router.ValidatedParamRoute = new(UserTasks)