package model

import (
	"fmt"
	"net/url"
	"time"

	"git.aiterp.net/AiteRP/aitestory/formparser"
	"git.aiterp.net/gisle/wrouter/generate"
	"github.com/microcosm-cc/bluemonday"
	"github.com/russross/blackfriday"
)

// PageCategories are used by the view model and page to enforce
// a limited selection of categories. I may move it to a configuration
var PageCategories = []string{
	"OoC",
	"Story",
	"Background",
	"Document",
	"News",
	"Item",
	"Info",
}

// PageTypes describes how the source is rendered. For now it's only markdown,
// but who knows what the future holds.
var PageTypes = []string{
	"Markdown",
}

// PageMinDate is the earliest date possible. Stories from Matriarch Eriana's childhood
// are thus not going to happen.
var PageMinDate, _ = time.Parse(time.RFC3339, "1753-01-01T00:00:00Z")

// Page is the model describing the individual articles posted
// by users.
type Page struct {
	ID            string    `json:"id"`
	Name          string    `json:"name"`
	Author        string    `json:"author"`
	Category      string    `json:"category"`
	FictionalDate time.Time `json:"fictionalDate"`
	PublishDate   time.Time `json:"publishDate"`
	EditDate      time.Time `json:"editDate"`
	Dated         bool      `json:"dated"`
	Published     bool      `json:"published"`
	Unlisted      bool      `json:"unlisted"`
	Specific      bool      `json:"specific"`
	Indexed       bool      `json:"indexed"`
	BackgroundURL string    `json:"backgroundUrl"`
	Type          string    `json:"type"`
	Source        string    `json:"source"`

	cachedOutput string
}

// Defaults fills in the default details for a page, suited for populating a form
func (page *Page) Defaults() {
	page.Category = PageCategories[0]

	page.Dated = true
	page.Published = true
	page.Unlisted = false
	page.Specific = false
	page.Indexed = true

	page.BackgroundURL = ""
	page.Type = PageTypes[0]
	page.Source = ""
}

// Insert adds the page to the database
func (page *Page) Insert() error {
	page.generateID()

	return nil
}

// Content parses the content of the page
func (page *Page) Content() (string, error) {
	if page.cachedOutput != "" {
		return page.cachedOutput, nil
	}

	if page.Type == "Markdown" {
		// TODO: Convert [[Ehanis Tioran]] to [Ehanis Tioran](https://wiki.aiterp.net/index.php?title=Ehanis%20Tioran)

		unsafe := blackfriday.MarkdownCommon([]byte(page.Source))
		page.cachedOutput = string(bluemonday.UGCPolicy().SanitizeBytes(unsafe))

		return page.cachedOutput, nil
	}

	return "", fmt.Errorf("Page type '%s' is not supported", page.Type)
}

// ParseForm validates the values in a form and sets the page's values whenever possible regardless
// so that it can be pushed to the viewmodel to allow the user to correct their mistakes without fear
// of losing their hard work
func (page *Page) ParseForm(form url.Values) []error {
	errors := make([]error, 0, 4)
	page.cachedOutput = ""

	err := formparser.Select(form.Get("category"), &page.Category, PageCategories, page.Category != "")
	if err != nil {
		errors = append(errors, fmt.Errorf("Category: %s", err))
	}

	err = formparser.Date(form.Get("fictionalDate"), &page.FictionalDate, !page.FictionalDate.IsZero())
	if err != nil {
		errors = append(errors, fmt.Errorf("Fictonal Date: %s", err))
	}

	page.Dated = form.Get("dated") != ""
	page.Published = form.Get("published") != ""
	page.Unlisted = form.Get("unlisted") != ""
	page.Specific = form.Get("specific") != ""
	page.Indexed = form.Get("indexed") != ""

	err = formparser.String(form.Get("backgroundUrl"), &page.BackgroundURL, 0, 255)
	if err != nil {
		errors = append(errors, fmt.Errorf("Background URL: %s", err))
	}

	err = formparser.Select(form.Get("type"), &page.Type, PageTypes, page.Type != "")
	if err != nil {
		errors = append(errors, fmt.Errorf("Category: %s", err))
	}

	err = formparser.String(form.Get("source"), &page.Source, 0, 102400)
	if err != nil {
		errors = append(errors, fmt.Errorf("Content is too long, max: 100 KB (~17,000 words)"))
	}

	if len(errors) > 0 {
		errors = nil
	}

	return errors
}

// Standardize page ID generation
func (page *Page) generateID() {
	page.ID = generate.FriendlyID(16)
}