package controllers

import (
	"fmt"
	"io"
	"mime/multipart"
	"net/http"
	"unicode/utf8"

	"git.myrkvi.com/myrkvi/bin/global"
	"git.myrkvi.com/myrkvi/bin/models"
	"git.myrkvi.com/myrkvi/bin/utils"
	"git.myrkvi.com/myrkvi/bin/views/components"
	"git.myrkvi.com/myrkvi/bin/views/pages"
	"github.com/alecthomas/chroma/lexers"
	"github.com/labstack/echo/v4"
)

func GetNewHandler(c echo.Context) error {
	values := c.QueryParams()
	wantsText := values.Has("text")
	return utils.RenderComponents(c, http.StatusOK, pages.NewFull(wantsText))
}

func PostNewHandler(c echo.Context) error {
	file, err := c.FormFile("file")
	text := c.FormValue("text")

	name := c.FormValue("name")
	description := c.FormValue("description")
	lang := c.FormValue("lang")
	ip := c.RealIP()

	if tooMany, period := ipHasTooManyUses(ip); tooMany {
		return utils.RenderErrorToast(c,
			fmt.Sprintf("This IP address has uploaded too many files in the %s", period),
		)
	}

	if (file == nil || err != nil) && text == "" {
		return utils.RenderErrorToast(c, "file or text must be provided")
	}

	code, adminCode, err := utils.GenerateCodes()
	if err != nil {
		return utils.RenderErrorToast(c, "server-side error occurred")
	}

	if file != nil {
		// Don't bother trying to convert the contents into a string if it is too large.
		if file.Size > 1024*1024 {
			return utils.RenderErrorToast(c, "file cannot be larger than 1 MiB")
		}

		text, err = getTextFromFile(file)
		if name == "" {
			name = file.Filename
		}
		if err != nil {
			return utils.RenderErrorToast(c, "server-side error occurred")
		}
	}
	if len([]byte(text)) > 1024*1024 {
		return utils.RenderErrorToast(c, "file cannot be larger than 1 MiB")
	}

	if !utf8.ValidString(text) {
		return utils.RenderErrorToast(c, "submitted content must be utf8")
	}

	// Determine language from file extension if not set.
	if lang == "" && name != "" {
		lexer := lexers.Match(name)
		if lexer != nil {
			lang = lexer.Config().Name
		}
	}

	createdFile, err := models.CreateNewBin(global.DB, text, name, description, lang, code, adminCode, ip)
	if err != nil {
		return utils.RenderErrorToast(c, "server-side error occurred")
	}

	binPartial := pages.BinPartial(createdFile)
	setTitle := components.SetTitle(name)

	utils.SetHeader(c, "HX-Push", fmt.Sprintf("/b/%s", code))
	return utils.RenderComponents(c, http.StatusOK,
		binPartial,
		setTitle,
	)
}

func getTextFromFile(fileHeader *multipart.FileHeader) (text string, err error) {
	f, err := fileHeader.Open()
	if err != nil {
		return
	}
	b, err := io.ReadAll(f)
	if err != nil {
		return
	}

	text = string(b)
	return
}

func ipHasTooManyUses(ip string) (tooMany bool, period string) {
	file := new(models.File)
	var dayCount int64
	global.DB.Model(file).
		Where("ip = ? AND created_date >= DATETIME('now', '-1 day')", ip).
		Count(&dayCount)

	var threeDayCount int64
	global.DB.Model(file).
		Where("ip = ? AND created_date >= DATETIME('now', '-3 days')", ip).
		Count(&threeDayCount)

	var weekCount int64
	global.DB.Model(file).
		Where("ip = ? AND created_date >= DATETIME('now', '-7 days')", ip).
		Count(&weekCount)

	var monthCount int64
	global.DB.Model(file).
		Where("ip = ? AND created_date >= DATETIME('now', '-1 month')", ip).
		Count(&monthCount)

	if dayCount > 20 {
		return true, "last day"
	} else if threeDayCount > 50 {
		return true, "last three days"
	} else if weekCount > 85 {
		return true, "last week"
	} else if monthCount > 300 {
		return true, "last month"
	}

	return false, ""

}