// This example only uses local HTTP and bounded streaming; it has no database.
package main

import (
	"io"
	"log"
	"net/http"
	"strings"

	omni "git.yuntuo.hk/k2safe/go-omni"
	"git.yuntuo.hk/k2safe/go-omni/contract"
	"git.yuntuo.hk/k2safe/go-omni/examples/compatibility/ids"
	"git.yuntuo.hk/k2safe/go-omni/httpx"
)

type echoRequest struct {
	ID   ids.ID `json:"id"`
	Data any    `json:"data"`
}

func main() {
	app := omni.New(omni.WithLogger(true))
	defer app.Close()
	app.Use(httpx.WrapMiddleware(func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			w.Header().Set("X-Example", "compatibility")
			next.ServeHTTP(w, r)
		})
	}))
	app.GET("/legacy", httpx.WrapHandler(http.HandlerFunc(http.NotFound)))
	binder := contract.MustNew[echoRequest](contract.ScalarOf[ids.ID]("string|int64", "string", true))
	app.POST("/echo", func(c *httpx.Context) error {
		var req echoRequest
		if err := binder.Bind(c.Request(), nil, &req); err != nil {
			return err
		}
		return c.OK(req)
	})
	app.HandleWithBodyLimit("POST", "/upload", 10<<20, nil, func(c *httpx.Context) error {
		reader, err := c.Request().MultipartReader()
		if err != nil {
			return omni.BadRequest("INVALID_MULTIPART", "multipart body required")
		}
		var total int64
		for {
			part, err := reader.NextPart()
			if err == io.EOF {
				break
			}
			if err != nil {
				return err
			}
			// Replace io.Discard with a streaming storage writer. Do not trust file names
			// as filesystem paths. io.Copy never buffers the complete uploaded file.
			n, copyErr := io.Copy(io.Discard, part)
			closeErr := part.Close()
			if copyErr != nil {
				return copyErr
			}
			if closeErr != nil {
				return closeErr
			}
			total += n
		}
		return c.OK(map[string]int64{"bytes": total})
	})
	app.GET("/download", httpx.WrapHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/octet-stream")
		w.Header().Set("Content-Disposition", `attachment; filename="example.txt"`)
		_, _ = io.Copy(w, strings.NewReader("A standard Handler keeps its original download response.\n"))
	})))
	if err := app.Run("127.0.0.1:8080"); err != nil {
		log.Fatal(err)
	}
}