package api

import (
	"encoding/hex"
	"encoding/json"
	"fmt"

	"srs.epita.fr/fic-server/admin/sync"
	"srs.epita.fr/fic-server/libfic"

	"github.com/julienschmidt/httprouter"
)

func init() {
	router.GET("/api/files/", apiHandler(listFiles))
	router.DELETE("/api/files/", apiHandler(clearFiles))

	router.GET("/api/files/:fileid", apiHandler(fileHandler(showFile)))
	router.PUT("/api/files/:fileid", apiHandler(fileHandler(updateFile)))
	router.DELETE("/api/files/:fileid", apiHandler(fileHandler(deleteFile)))

	router.DELETE("/api/files/:fileid/dependancies/:depid", apiHandler(fileDependancyHandler(deleteFileDep)))

	router.GET("/api/exercices/:eid/files", apiHandler(exerciceHandler(listExerciceFiles)))
	router.POST("/api/exercices/:eid/files", apiHandler(exerciceHandler(createExerciceFile)))

	router.GET("/api/exercices/:eid/files/:fid", apiHandler(exerciceFileHandler(showFile)))
	router.PUT("/api/exercices/:eid/files/:fid", apiHandler(exerciceFileHandler(updateFile)))
	router.DELETE("/api/exercices/:eid/files/:fid", apiHandler(exerciceFileHandler(deleteFile)))

	// Remote
	router.GET("/api/remote/themes/:thid/exercices/:exid/files", apiHandler(sync.ApiGetRemoteExerciceFiles))

	// Check
	router.POST("/api/files/:fileid/check", apiHandler(fileHandler(checkFile)))

	// Synchronize
	router.POST("/api/sync/exercices/:eid/files", apiHandler(exerciceHandler(
		func(exercice fic.Exercice, _ []byte) (interface{}, error) {
			return sync.SyncExerciceFiles(sync.GlobalImporter, exercice), nil
		})))
}

type APIFile struct {
	fic.EFile
	Depends []fic.Flag `json:"depends,omitempty"`
}

func genFileList(in []fic.EFile, e error) (out []APIFile, err error) {
	if e != nil {
		return nil, e
	}

	for _, f := range in {
		g := APIFile{EFile: f}

		var deps []fic.Flag
		deps, err = f.GetDepends()
		if err != nil {
			return
		}

		for _, d := range deps {
			if k, ok := d.(fic.FlagKey); ok {
				k, err = fic.GetFlagKey(k.Id)
				if err != nil {
					return
				}

				g.Depends = append(g.Depends, k)
			} else if m, ok := d.(fic.MCQ); ok {
				m, err = fic.GetMCQ(m.Id)
				if err != nil {
					return
				}

				g.Depends = append(g.Depends, m)
			} else {
				err = fmt.Errorf("Unknown type %T to handle file dependancy", k)
				return
			}
		}

		out = append(out, g)
	}

	return
}

func listFiles(_ httprouter.Params, body []byte) (interface{}, error) {
	return genFileList(fic.GetFiles())
}

func listExerciceFiles(exercice fic.Exercice, body []byte) (interface{}, error) {
	return genFileList(exercice.GetFiles())
}

func clearFiles(_ httprouter.Params, _ []byte) (interface{}, error) {
	return fic.ClearFiles()
}

func showFile(file fic.EFile, _ []byte) (interface{}, error) {
	return file, nil
}

type uploadedFile struct {
	URI    string
	Digest string
}

func createExerciceFile(exercice fic.Exercice, body []byte) (interface{}, error) {
	var uf uploadedFile
	if err := json.Unmarshal(body, &uf); err != nil {
		return nil, err
	}

	return sync.ImportFile(sync.GlobalImporter, uf.URI,
		func(filePath string, origin string) (interface{}, error) {
			if digest, err := hex.DecodeString(uf.Digest); err != nil {
				return nil, err
			} else {
				return exercice.ImportFile(filePath, origin, digest)
			}
		})
}

func updateFile(file fic.EFile, body []byte) (interface{}, error) {
	var uf fic.EFile
	if err := json.Unmarshal(body, &uf); err != nil {
		return nil, err
	}

	uf.Id = file.Id

	if _, err := uf.Update(); err != nil {
		return nil, err
	} else {
		return uf, nil
	}
}

func deleteFile(file fic.EFile, _ []byte) (interface{}, error) {
	return file.Delete()
}

func deleteFileDep(file fic.EFile, depid int, _ []byte) (interface{}, error) {
	return true, file.DeleteDepend(fic.FlagKey{Id: depid})
}

func checkFile(file fic.EFile, _ []byte) (interface{}, error) {
	return true, file.CheckFileOnDisk()
}