package openngvfs

import (
	"context"
	"fmt"
	"git.swzry.com/ProjectNagae/FsUtils/amntfs"
	"git.swzry.com/zry/GoHiedaLogger/hiedalog"
	"git.swzry.com/zry/go-int32-handle"
	"github.com/spf13/afero"
	"github.com/tetratelabs/wazero"
	wa_api "github.com/tetratelabs/wazero/api"
	"os"
)

const API_VERSION_MAJOR = 1
const API_VERSION_MINOR = 1
const API_VERSION_PATCH = 0

type AferoFsInstance struct {
	Fs              afero.Fs
	TypeDescription string
}

type InitWAVMHostAPI struct {
	Root                *amntfs.AMNTFS
	AferoFsInstancesMgr *go_int32_handle.HandleManager[*AferoFsInstance]
}

func NewWAVMHostAPI(root *amntfs.AMNTFS) *InitWAVMHostAPI {
	return &InitWAVMHostAPI{
		Root:                root,
		AferoFsInstancesMgr: go_int32_handle.New[*AferoFsInstance](),
	}
}

type InitWAVMHostModuleAdapter struct {
	api            *InitWAVMHostAPI
	builder        wazero.HostModuleBuilder
	rawFsTab       *RawFsTab
	processedFsTab *ProcessedFsTab
	logger         *hiedalog.HiedaLogger
}

func NewInitWAVMHostModuleAdapter(builder wazero.HostModuleBuilder, api *InitWAVMHostAPI, fstab *RawFsTab, logger *hiedalog.HiedaLogger, appName string) *InitWAVMHostModuleAdapter {
	localKV := make(map[string]string)
	for k, v := range fstab.ExKV.Default {
		localKV[k] = v
	}
	appKV, ok := fstab.ExKV.App[appName]
	if ok {
		for k, v := range appKV {
			localKV[k] = v
		}
	}
	processedFsTab := &ProcessedFsTab{
		ExKV: localKV,
	}
	return &InitWAVMHostModuleAdapter{
		api:            api,
		builder:        builder,
		rawFsTab:       fstab,
		processedFsTab: processedFsTab,
		logger:         logger,
	}
}

func (a *InitWAVMHostModuleAdapter) addFunc(
	name string, f func(ctx context.Context, mod wa_api.Module, params []uint64),
	param []wa_api.ValueType, result []wa_api.ValueType,
) {
	a.builder = a.builder.NewFunctionBuilder().
		WithGoModuleFunction(wa_api.GoModuleFunc(f), param, result).Export(name)
}

func (a *InitWAVMHostModuleAdapter) Instantiate(ctx context.Context) (wa_api.Module, error) {
	a.addFunc("api_ver_get", a.efnApiVerGet,
		[]wa_api.ValueType{
			wa_api.ValueTypeI32, wa_api.ValueTypeI32, wa_api.ValueTypeI32,
		}, []wa_api.ValueType{})
	a.addFunc("exkv_get_len", a.efnExkvGetLen,
		[]wa_api.ValueType{wa_api.ValueTypeI32, wa_api.ValueTypeI32},
		[]wa_api.ValueType{wa_api.ValueTypeI32})
	a.addFunc("exkv_get_val", a.efnExkvGetVal,
		[]wa_api.ValueType{
			wa_api.ValueTypeI32, wa_api.ValueTypeI32,
			wa_api.ValueTypeI32, wa_api.ValueTypeI32,
		},
		[]wa_api.ValueType{wa_api.ValueTypeI32})
	a.addFunc("vfs_mount", a.efnVfsMount,
		[]wa_api.ValueType{
			wa_api.ValueTypeI32, wa_api.ValueTypeI32, wa_api.ValueTypeI32,
		},
		[]wa_api.ValueType{wa_api.ValueTypeI32})
	a.addFunc("vfs_mkdir", a.efnVfsMkdir,
		[]wa_api.ValueType{
			wa_api.ValueTypeI32, wa_api.ValueTypeI32, wa_api.ValueTypeI32,
		},
		[]wa_api.ValueType{wa_api.ValueTypeI32})
	a.mfaAddAfs()
	return a.builder.Instantiate(ctx)
}

func (a *InitWAVMHostModuleAdapter) efnApiVerGet(_ context.Context, mod wa_api.Module, stack []uint64) {
	ptrMaj := uint32(stack[0])
	ptrMin := uint32(stack[1])
	ptrPat := uint32(stack[2])
	mod.Memory().WriteUint32Le(ptrMaj, API_VERSION_MAJOR)
	mod.Memory().WriteUint32Le(ptrMin, API_VERSION_MINOR)
	mod.Memory().WriteUint32Le(ptrPat, API_VERSION_PATCH)
}

func (a *InitWAVMHostModuleAdapter) efnExkvGetLen(_ context.Context, mod wa_api.Module, stack []uint64) {
	ptrKey := uint32(stack[0])
	lenKey := uint32(stack[1])
	key, ok := mod.Memory().Read(ptrKey, lenKey)
	if !ok {
		var neg1 int32 = -1
		stack[0] = uint64(neg1)
		return
	}
	v, ok := a.processedFsTab.ExKV[string(key)]
	if !ok {
		var neg2 int32 = -2
		stack[0] = uint64(neg2)
	} else {
		stack[0] = uint64(len([]byte(v)))
	}
}

func (a *InitWAVMHostModuleAdapter) efnExkvGetVal(_ context.Context, mod wa_api.Module, stack []uint64) {
	ptrKey := uint32(stack[0])
	lenKey := uint32(stack[1])
	ptrBuf := uint32(stack[2])
	lenBuf := uint32(stack[3])
	if lenBuf <= 0 {
		stack[0] = 0
		return
	}
	key, ok := mod.Memory().Read(ptrKey, lenKey)
	if !ok {
		var neg1 int32 = -1
		stack[0] = uint64(neg1)
		return
	}
	v, ok := a.processedFsTab.ExKV[string(key)]
	if !ok {
		var neg2 int32 = -2
		stack[0] = uint64(neg2)
		return
	}
	vb := []byte(v)
	ok = mod.Memory().Write(ptrBuf, vb[:lenBuf])
	if !ok {
		var neg3 int32 = -3
		stack[0] = uint64(neg3)
		return
	}
	stack[0] = uint64(lenBuf)
	return
}

func (a *InitWAVMHostModuleAdapter) efnVfsMount(_ context.Context, mod wa_api.Module, stack []uint64) {
	hAfs := int32(stack[0])
	ptrMntPath := uint32(stack[1])
	lenMntPath := uint32(stack[2])
	mntPath, ok := mod.Memory().Read(ptrMntPath, lenMntPath)
	if !ok {
		var neg2 int32 = -2
		stack[0] = uint64(neg2)
		return
	}
	if hAfs <= 0 {
		var neg1 int32 = -1
		stack[0] = uint64(neg1)
		return
	}
	objAfs, ok := a.api.AferoFsInstancesMgr.Get(hAfs)
	if !ok {
		var neg1 int32 = -1
		stack[0] = uint64(neg1)
		return
	}
	err := a.api.Root.Mount(string(mntPath), objAfs.Fs, false)
	if err != nil {
		if aErr, ok := err.(*amntfs.AMNTFSError); ok {
			rawErr := aErr.GetRawError()
			var rawErrStr string
			if rawErr != nil {
				rawErrStr = rawErr.Error()
			} else {
				rawErrStr = ""
			}
			if aErr.GetErrNo() == amntfs.ErrMountPointAlreadyMounted {
				a.logger.LogComplex("ngvfs", hiedalog.DLN_WARN, map[string]string{
					"type":          "mount_error",
					"sub-type":      "mount_point_already_mounted",
					"mnt-point":     string(mntPath),
					"afs-name":      objAfs.Fs.Name(),
					"afs-type-desc": objAfs.TypeDescription,
				})
				var neg3 int32 = -3
				stack[0] = uint64(neg3)
				return
			} else {
				a.logger.LogComplex("ngvfs", hiedalog.DLN_WARN, map[string]string{
					"type":          "mount_error",
					"sub-type":      "internal_error",
					"mnt-point":     string(mntPath),
					"afs-name":      objAfs.Fs.Name(),
					"afs-type-desc": objAfs.TypeDescription,
					"raw-err":       rawErrStr,
				})
				var neg4 int32 = -4
				stack[0] = uint64(neg4)
				return
			}
		} else {
			a.logger.LogComplex("ngvfs", hiedalog.DLN_WARN, map[string]string{
				"type":          "mount_error",
				"sub-type":      "internal_error",
				"mnt-point":     string(mntPath),
				"afs-name":      objAfs.Fs.Name(),
				"afs-type-desc": objAfs.TypeDescription,
				"raw-err":       err.Error(),
			})
			var neg4 int32 = -4
			stack[0] = uint64(neg4)
			return
		}
	}
	a.logger.LogComplex("ngvfs", hiedalog.DLN_VERBOSE, map[string]string{
		"type":          "mount_ok",
		"mnt-point":     string(mntPath),
		"afs-name":      objAfs.Fs.Name(),
		"afs-type-desc": objAfs.TypeDescription,
	})
	stack[0] = 0
	return
}

func (a *InitWAVMHostModuleAdapter) efnVfsMkdir(_ context.Context, mod wa_api.Module, stack []uint64) {
	ptrPath := uint32(stack[0])
	lenPath := uint32(stack[1])
	perm := uint32(stack[2])
	dirPath, ok := mod.Memory().Read(ptrPath, lenPath)
	if !ok {
		var neg2 int32 = -1
		stack[0] = uint64(neg2)
		return
	}
	err := a.api.Root.MkdirAll(string(dirPath), os.FileMode(perm))
	if err != nil {
		a.logger.LogComplex("ngvfs", hiedalog.DLN_WARN, map[string]string{
			"type":     "vfs_mkdir_error",
			"dir-path": string(dirPath),
			"perm":     fmt.Sprintf("%04o", perm),
			"raw-err":  err.Error(),
		})
		var ecode int32 = -2
		stack[0] = uint64(ecode)
		return
	}
	a.logger.LogComplex("ngvfs", hiedalog.DLN_VERBOSE, map[string]string{
		"type": "vfs_mkdir_ok",
		"path": string(dirPath),
	})
	stack[0] = 0
	return
}