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/gin-gonic/gin"
)

// 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 := gin.Default()
	h.LoadRoutes(router)

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

type ErrorResponse struct {
	Message string
}

// LoadRoutes initializes all the routes.
func (h *Handler) LoadRoutes(router *gin.Engine) {
	router.Use(enableCachingForStaticFiles())
	router.NoRoute(h.ServeStatic)

	withLogin := router.Group("")
	withLogin.Use(h.verifyLoginWithRedirect)

	withBudget := router.Group("")
	withBudget.Use(h.verifyLoginWithForbidden)
	withBudget.GET("/budget/:budgetid/:year/:month", h.budgeting)
	withBudget.GET("/budget/:budgetid/settings/clean-negative", h.cleanNegativeBudget)

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

	unauthenticated := api.Group("/user")
	unauthenticated.GET("/login", func(c *gin.Context) { c.Redirect(http.StatusPermanentRedirect, "/login") })
	unauthenticated.POST("/login", h.loginPost)
	unauthenticated.POST("/register", h.registerPost)

	authenticated := api.Group("")
	authenticated.Use(h.verifyLoginWithForbidden)
	authenticated.GET("/dashboard", h.dashboard)
	authenticated.GET("/account/:accountid/transactions", h.transactionsForAccount)
	authenticated.GET("/admin/clear-database", h.clearDatabase)
	authenticated.GET("/budget/:budgetid", h.budgeting)
	authenticated.GET("/budget/:budgetid/:year/:month", h.budgetingForMonth)
	authenticated.GET("/budget/:budgetid/autocomplete/payees", h.autocompletePayee)
	authenticated.GET("/budget/:budgetid/autocomplete/categories", h.autocompleteCategories)
	authenticated.DELETE("/budget/:budgetid", h.deleteBudget)
	authenticated.POST("/budget/:budgetid/import/ynab", h.importYNAB)
	authenticated.POST("/budget/:budgetid/export/ynab/transactions", h.exportYNABTransactions)
	authenticated.POST("/budget/:budgetid/export/ynab/assignments", h.exportYNABAssignments)
	authenticated.POST("/budget/:budgetid/settings/clear", h.clearBudget)

	budget := authenticated.Group("/budget")
	budget.POST("/new", h.newBudget)

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

func (h *Handler) ServeStatic(c *gin.Context) {
	h.ServeStaticFile(c, c.Request.URL.Path)
}

func (h *Handler) ServeStaticFile(c *gin.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.AbortWithError(http.StatusInternalServerError, err)
		return
	}

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

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

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

func enableCachingForStaticFiles() gin.HandlerFunc {
	return func(c *gin.Context) {
		if strings.HasPrefix(c.Request.RequestURI, "/static/") {
			c.Header("Cache-Control", "max-age=86400")
		}
	}
}