package server

import (
	"errors"
	"io"
	"io/fs"
	"net/http"
	"path"
	"strings"

	"git.javil.eu/jacob1123/budgeteer"
	"git.javil.eu/jacob1123/budgeteer/bcrypt"
	"git.javil.eu/jacob1123/budgeteer/postgres"

	"github.com/labstack/echo/v4"
)

// Handler handles incoming requests.
type Handler struct {
	Service             *postgres.Database
	TokenVerifier       budgeteer.TokenVerifier
	CredentialsVerifier *bcrypt.Verifier
	StaticFS            http.FileSystem
}

// Serve starts the http server.
func (h *Handler) Serve() {
	router := echo.New()
	h.LoadRoutes(router)

	if err := router.Start(":1323"); err != nil {
		panic(err)
	}
}

// LoadRoutes initializes all the routes.
func (h *Handler) LoadRoutes(router *echo.Echo) {
	router.Use(enableCachingForStaticFiles())
	router.Use(h.ServeStatic)

	api := router.Group("/api/v1")

	anonymous := api.Group("/user")
	anonymous.POST("/login", h.loginPost)
	anonymous.POST("/register", h.registerPost)

	authenticated := api.Group("")
	{
		authenticated.Use(h.verifyLoginWithForbidden)
		authenticated.GET("/account/:accountid/transactions", h.transactionsForAccount)
		authenticated.POST("/account/:accountid/reconcile", h.reconcileTransactions)
		authenticated.POST("/account/:accountid", h.editAccount)
		authenticated.GET("/admin/clear-database", h.clearDatabase)

		budget := authenticated.Group("/budget")
		budget.POST("/new", h.newBudget)
		budget.GET("/:budgetid", h.budget)
		budget.GET("/:budgetid/:year/:month", h.budgetingForMonth)
		budget.POST("/:budgetid/category/:categoryid/:year/:month", h.setCategoryAssignment)
		budget.GET("/:budgetid/autocomplete/payees", h.autocompletePayee)
		budget.GET("/:budgetid/autocomplete/accounts", h.autocompleteAccounts)
		budget.GET("/:budgetid/autocomplete/categories", h.autocompleteCategories)
		budget.GET("/:budgetid/problematic-transactions", h.problematicTransactions)
		budget.POST("/:budgetid/filtered-transactions", h.filteredTransactions)
		budget.DELETE("/:budgetid", h.deleteBudget)
		budget.POST("/:budgetid/import/ynab", h.importYNAB)
		budget.POST("/:budgetid/export/ynab/transactions", h.exportYNABTransactions)
		budget.POST("/:budgetid/export/ynab/assignments", h.exportYNABAssignments)
		budget.POST("/:budgetid/settings/clear", h.clearBudget)

		transaction := authenticated.Group("/transaction")
		transaction.POST("/new", h.newTransaction)
		transaction.POST("/:transactionid", h.updateTransaction)
	}
}

func (h *Handler) ServeStatic(next echo.HandlerFunc) echo.HandlerFunc {
	return func(c echo.Context) error {
		h.ServeStaticFile(c, c.Path())
		return nil
	}
}

func (h *Handler) ServeStaticFile(c echo.Context, fullPath string) {
	file, err := h.StaticFS.Open(fullPath)
	if errors.Is(err, fs.ErrNotExist) {
		h.ServeStaticFile(c, path.Join("/", "/index.html"))
		return
	}

	if err != nil {
		c.Error(err)
		return
	}

	stat, err := file.Stat()
	if err != nil {
		c.Error(err)
		return
	}

	if stat.IsDir() {
		h.ServeStaticFile(c, path.Join(fullPath, "index.html"))
		return
	}

	if file, ok := file.(io.ReadSeeker); ok {
		http.ServeContent(c.Response().Writer, c.Request(), stat.Name(), stat.ModTime(), file)
	} else {
		panic("File does not implement ReadSeeker")
	}
}

func enableCachingForStaticFiles() echo.MiddlewareFunc {
	return func(next echo.HandlerFunc) echo.HandlerFunc {
		return func(c echo.Context) error {
			if strings.HasPrefix(c.Path(), "/static/") {
				c.Response().Header().Set("Cache-Control", "max-age=86400")
			}

			return next(c)
		}
	}
}