package main

import (
	"encoding/json"
	"errors"
	"io"
	"net/http"
	"os"
	"path"
	"strings"

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

// GET /
func MainHandle(c echo.Context) error {
	m := map[string]any{
		"cod":     200,
		"id":      "JGoServer",
		"version": "1.0-dev",
	}
	ents, err := os.ReadDir("storage")
	if errors.Is(err, os.ErrNotExist) {
		err2 := os.Mkdir("storage", 0775)
		if err2 != nil {
			m["cod"] = 500
			m["dirs"] = nil // This is what we were trying to populate
			m["err"] = err2.Error()
			m["cause"] = err.Error()
			return c.JSON(m["cod"].(int), m)
		}
	} else if err != nil {
		m["cod"] = 500
		m["dirs"] = nil // This is what we were trying to populate
		m["err"] = err.Error()
		return c.JSON(m["cod"].(int), m)
	}
	dirs := []string{}
	for _, e := range ents {
		if e.IsDir() {
			dirs = append(dirs, e.Name())
		}
	}
	m["dirs"] = dirs
	return c.JSON(m["cod"].(int), m)
}

// Sanitizes directory name so it's a little safe
func CleanDirName(raw string) string {
	return strings.ToLower(strings.Trim(raw, " .\r\n\t"))
}

// GET /dir?q=<dir>
func GetDirHandle(c echo.Context) error {
	m := map[string]any{
		"cod": 200,
	}
	target := CleanDirName(c.QueryParam("q")) // Directory to list
	if len(target) == 0 || target == "" {
		// Nothing todo?
		m["cod"] = http.StatusBadRequest
		m["q"] = c.QueryParam("q")
		return c.JSON(m["cod"].(int), m)
	}
	// Verify the directory at least exists
	_, err := os.Stat(path.Join("storage", target))
	if errors.Is(err, os.ErrNotExist) {
		err2 := os.MkdirAll(path.Join("storage", target), 0775)
		if err2 != nil {
			m["cod"] = 500
			m["files"] = nil
			m["dirs"] = nil
			m["err"] = err2.Error()
			m["cause"] = err.Error()
			return c.JSON(m["cod"].(int), m)
		}
	} else if err != nil {
		m["cod"] = 500
		m["files"] = nil
		m["dirs"] = nil
		m["err"] = err.Error()
		return c.JSON(m["cod"].(int), m)
	}
	// Scan the dirs looking for files (won't include ones that start with .)
	var scanDir func(string) ([]string, []string, error)
	scanDir = func(dir string) ([]string, []string, error) {
		ents, err := os.ReadDir(dir)
		if err != nil {
			return nil, nil, err
		}
		fs := []string{}
		ds := []string{}
		for _, e := range ents {
			if strings.HasPrefix(e.Name(), ".") { // Keep hidden files/dirs hidden
				continue
			}
			if e.IsDir() {
				ds = append(ds, path.Join(dir, e.Name()))
				f, d, err := scanDir(path.Join(dir, e.Name()))
				if err != nil {
					return nil, nil, err
				}
				fs = append(fs, f...)
				ds = append(ds, d...)
			} else {
				fs = append(fs, path.Join(dir, e.Name()))
			}
		}
		return fs, ds, nil
	}
	files, dirs, err2 := scanDir(path.Join("storage", target))
	if err2 != nil {
		m["cod"] = 500
		m["files"] = nil
		m["dirs"] = nil
		m["err"] = err.Error()
		return c.JSON(m["cod"].(int), m)
	}
	m["files"] = files
	m["dirs"] = dirs
	return c.JSON(m["cod"].(int), m)
}

// POST/PUT /up?q=<filepath>
func UploadJData(c echo.Context) error {
	// e.g. test/dir1/pkt001.json
	targetDir := CleanDirName(path.Dir(c.QueryParam("q"))) // e.g. test/dir1
	targetName := path.Base(c.QueryParam("q"))             // e.g. pkt001.json
	_, err := os.Stat(path.Join("storage", targetDir))
	if errors.Is(err, os.ErrNotExist) {
		err2 := os.MkdirAll(path.Join("storage", targetDir), 0775)
		if err2 != nil {
			return c.JSON(500, map[string]any{
				"cod":   500,
				"err":   err2.Error(),
				"cause": err.Error(),
			})
		}
	} else if err != nil {
		return c.JSON(500, map[string]any{
			"cod": 500,
			"err": err.Error(),
		})
	}
	fh, err := os.Create(path.Join("storage", targetDir, targetName))
	if err != nil {
		return c.JSON(500, map[string]any{
			"cod": 500,
			"err": err.Error(),
		})
	}
	body := c.Request().Body
	defer body.Close()
	written, err := io.Copy(fh, body)
	fh.Close()
	if err != nil {
		return c.JSON(500, map[string]any{
			"cod": 500,
			"err": err.Error(),
		})
	}
	// Check that it is in fact really JSON
	data, err := os.ReadFile(path.Join("storage", targetDir, targetName))
	if err != nil {
		return c.JSON(500, map[string]any{
			"cod": 500,
			"err": err.Error(),
		})
	}
	var test any
	err = json.Unmarshal(data, &test)
	if err != nil {
		// Not json!
		err2 := os.Remove(path.Join("storage", targetDir, targetName))
		if err2 != nil {
			return c.JSON(500, map[string]any{
				"cod":   500,
				"err":   err2.Error(),
				"cause": err.Error(),
			})
		}
		return c.JSON(500, map[string]any{
			"cod": 500,
			"err": err.Error(),
		})
	}
	// Ok we're good
	return c.JSON(200, map[string]any{
		"cod":  200,
		"size": bytemath.ConvertBytesToHumanReadable(written),
	})
}

// GET /down?q=<filepath>
func DownloadJData(c echo.Context) error {
	// e.g. test/dir1/pkt001.json
	targetDir := CleanDirName(path.Dir(c.QueryParam("q"))) // e.g. test/dir1
	targetName := path.Base(c.QueryParam("q"))             // e.g. pkt001.json
	_, err := os.ReadDir(path.Join("storage", targetDir))
	if errors.Is(err, os.ErrNotExist) {
		err2 := os.MkdirAll(path.Join("storage", targetDir), 0775)
		if err2 != nil {
			return c.JSON(500, map[string]any{
				"cod":   500,
				"err":   err2.Error(),
				"cause": err.Error(),
			})
		}
	} else if err != nil {
		return c.JSON(500, map[string]any{
			"cod": 500,
			"err": err.Error(),
		})
	}
	// File contents must be JSON, we live in JSON so it must be JSON data
	fh, err := os.ReadFile(path.Join("storage", targetDir, targetName))
	if err != nil {
		return c.JSON(500, map[string]any{
			"cod":  500,
			"err":  "ReadFile: " + err.Error(),
			"data": nil,
		})
	}
	var data any
	err = json.Unmarshal(fh, &data)
	if err != nil {
		return c.JSON(500, map[string]any{
			"cod":  500,
			"err":  "json.Unmarshal: " + err.Error(),
			"data": nil,
		})
	}
	return c.JSON(200, map[string]any{
		"cod":  200,
		"data": data,
		"size": bytemath.ConvertBytesToHumanReadable(int64(len(fh))),
	})
}