package configui

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
	"path/filepath"
	"strconv"
	"time"

	"kumoly.io/lib/ksrv"
)

func (cui *ConfigUI) ListFiles(w http.ResponseWriter, r *http.Request) {
	data, err := json.Marshal(cui.Files)
	if err != nil {
		panic(err)
	}
	w.Write(data)
}

func (cui *ConfigUI) GetFile(w http.ResponseWriter, r *http.Request) {
	name := r.URL.Query().Get("name")
	file, err := cui.File(name)
	if err != nil {
		ksrv.Response(w, 404, []byte("file not found"))
		return
	}
	data, err := file.Read()
	if err != nil {
		panic(err)
	}
	stat, err := os.Stat(file.Path)
	if err != nil {
		panic(err)
	}
	response, err := json.Marshal(map[string]string{
		"path":  file.Path,
		"name":  file.Name,
		"cmd":   file.Cmd,
		"data":  string(data),
		"delta": strconv.Itoa(int(stat.Size())),
	})
	if err != nil {
		panic(err)
	}
	w.Header().Set("Content-Type", "application/json")
	w.Write(response)
}

func (cui *ConfigUI) GetDelta(w http.ResponseWriter, r *http.Request) {
	name := r.URL.Query().Get("name")
	delta, err := strconv.ParseInt(r.URL.Query().Get("delta"), 10, 64)
	if err != nil {
		panic(err)
	}
	file, err := cui.File(name)
	if err != nil {
		ksrv.Response(w, 404, []byte("file not found"))
		return
	}
	f, err := os.Open(file.Path)
	if err != nil {
		panic(err)
	}
	defer f.Close()

	stat, err := os.Stat(file.Path)
	if err != nil {
		panic(err)
	}
	if delta > stat.Size() {
		panic(fmt.Errorf("delta(%d) is larger than file size(%d), the file might have been changed", delta, stat.Size()))
	}
	buf := make([]byte, stat.Size()-delta)
	_, err = f.ReadAt(buf, delta)
	if err != nil {
		panic(err)
	}

	response, err := json.Marshal(map[string]string{
		"path":  file.Path,
		"name":  file.Name,
		"cmd":   file.Cmd,
		"data":  string(buf),
		"delta": strconv.Itoa(int(stat.Size())),
	})
	if err != nil {
		panic(err)
	}
	w.Header().Set("Content-Type", "application/json")
	w.Write(response)
}

func (cui *ConfigUI) PostFile(w http.ResponseWriter, r *http.Request) {
	data, err := ioutil.ReadAll(r.Body)
	r.Body.Close()
	if err != nil {
		panic(err)
	}
	f := File{}
	if err := json.Unmarshal(data, &f); err != nil {
		panic(err)
	}
	file, err := cui.File(f.Name)
	if err != nil {
		ksrv.Response(w, 404, []byte("file not found"))
		return
	}
	if err := file.Write([]byte(f.Data)); err != nil {
		panic(err)
	}
	w.Write([]byte("ok"))
}

func (cui *ConfigUI) Apply(w http.ResponseWriter, r *http.Request) {
	name := r.URL.Query().Get("name")
	file, err := cui.File(name)
	if err != nil {
		ksrv.Response(w, 404, []byte("file not found"))
		return
	}
	result, err := file.Do(cui.cmdTimeout)
	if err != nil {
		panic(err)
	}
	w.Write([]byte(result))
}

func (cui *ConfigUI) DoAction(w http.ResponseWriter, r *http.Request) {
	name := r.URL.Query().Get("name")
	for i, v := range cui.Actions {
		if v.Name == name {

			// limit running instance to one
			if cap(cui.Actions[i].run) != 1 {
				cui.Actions[i].run = make(chan struct{}, 1)
			}
			select {
			case cui.Actions[i].run <- struct{}{}:
				defer func() { <-cui.Actions[i].run }()
			default:
				panic(fmt.Errorf("another task of %s is running with pid: %d", name, v.pid))
			}

			file := &File{Name: name, Action: v.Cmd, owner: cui}
			go func() {
				<-time.After(time.Millisecond * 10)
				cui.Actions[i].pid = file.pid
			}()
			result, err := file.Do(cui.cmdTimeout)
			if err != nil {
				panic(err)
			}
			w.Write([]byte(result))
			return
		}
	}
	panic(fmt.Errorf("no action named: %v", name))
}

func (cui *ConfigUI) DoIntegration(w http.ResponseWriter, r *http.Request) {
	name := r.URL.Query().Get("name")
	for i, v := range cui.Integrations {
		if v.Name == name {

			// limit running instance to one
			if cap(cui.Integrations[i].run) != 1 {
				cui.Integrations[i].run = make(chan struct{}, 1)
			}
			select {
			case cui.Integrations[i].run <- struct{}{}:
				defer func() { <-cui.Integrations[i].run }()
			default:
				panic(fmt.Errorf("another task of %s is running", name))
			}

			result, err := v.Cmd()
			if err != nil {
				panic(err)
			}
			w.Write([]byte(result))
			return
		}
	}
	panic(fmt.Errorf("no integration named: %v", name))
}

func (cui *ConfigUI) Download(w http.ResponseWriter, r *http.Request) {
	if name := r.URL.Query().Get("name"); name != "" {
		if name == cui.AppName {
			data, err := cui.Config()
			if err != nil {
				panic(err)
			}
			w.Header().Set(
				"Content-Disposition", `
				attachment; filename="`+cui.AppName+`.json"`,
			)
			w.Write(data)
			return
		}
		file, err := cui.File(name)
		if err != nil {
			ksrv.Response(w, 404, []byte("file not found"))
			return
		}
		data, err := file.Read()
		if err != nil {
			panic(err)
		}
		w.Header().Set("Content-Disposition", `attachment; filename="`+filepath.Base(file.Path)+`"`)
		w.Write(data)
		return
	}
	fs := []string{}
	for _, i := range cui.fileIndex {
		fs = append(fs, cui.Files[i].Path)
	}
	if cui.ConfigPath != "" {
		fs = append(fs, cui.ConfigPath)
	}
	w.Header().Set("Content-Disposition", `attachment; filename="export.tar.gz"`)
	bundle(w, fs, cui.AppName, false)
}

func (cui *ConfigUI) PostConfig(w http.ResponseWriter, r *http.Request) {
	if cui.NoReconfig {
		panic("system reconfig is disabled")
	}
	data, err := ioutil.ReadAll(r.Body)
	r.Body.Close()
	if err != nil {
		panic(err)
	}
	err = cui.LoadConfig(string(data))
	if err != nil {
		panic(err)
	}
	if cui.ConfigPath != "" {
		info, err := os.Stat(cui.ConfigPath)
		if err != nil {
			panic(err)
		}
		err = os.WriteFile(cui.ConfigPath, data, info.Mode())
		if err != nil {
			panic(err)
		}
	}
	w.Write([]byte("ok"))
}

func (cui *ConfigUI) GetConfig(w http.ResponseWriter, r *http.Request) {
	data, err := cui.Config()
	if err != nil {
		panic(err)
	}
	w.Write(data)
}