// Copyright (c) 2026 Lark Technologies Pte. Ltd.
// SPDX-License-Identifier: MIT

package service

import (
	"context"
	"fmt"
	"io"
	"strings"

	"github.com/larksuite/cli/errs"
	"github.com/larksuite/cli/internal/auth"
	"github.com/larksuite/cli/internal/client"
	"github.com/larksuite/cli/internal/cmdutil"
	"github.com/larksuite/cli/internal/core"
	"github.com/larksuite/cli/internal/credential"
	"github.com/larksuite/cli/internal/errclass"
	"github.com/larksuite/cli/internal/output"
	"github.com/larksuite/cli/internal/registry"
	"github.com/larksuite/cli/internal/util"
	"github.com/larksuite/cli/internal/validate"
	larkcore "github.com/larksuite/oapi-sdk-go/v3/core"
	"github.com/spf13/cobra"
)

// RegisterServiceCommands registers all service commands from from_meta specs.
func RegisterServiceCommands(parent *cobra.Command, f *cmdutil.Factory) {
	RegisterServiceCommandsWithContext(context.Background(), parent, f)
}

func RegisterServiceCommandsWithContext(ctx context.Context, parent *cobra.Command, f *cmdutil.Factory) {
	for _, project := range registry.ListFromMetaProjects() {
		spec := registry.LoadFromMeta(project)
		if spec == nil {
			continue
		}
		specName := registry.GetStrFromMap(spec, "name")
		servicePath := registry.GetStrFromMap(spec, "servicePath")
		if specName == "" || servicePath == "" {
			continue
		}
		resources, _ := spec["resources"].(map[string]interface{})
		if resources == nil {
			continue
		}
		registerServiceWithContext(ctx, parent, spec, resources, f)
	}
}

func registerService(parent *cobra.Command, spec map[string]interface{}, resources map[string]interface{}, f *cmdutil.Factory) {
	registerServiceWithContext(context.Background(), parent, spec, resources, f)
}

func registerServiceWithContext(ctx context.Context, parent *cobra.Command, spec map[string]interface{}, resources map[string]interface{}, f *cmdutil.Factory) {
	specName := registry.GetStrFromMap(spec, "name")
	specDesc := registry.GetServiceDescription(specName, "en")
	if specDesc == "" {
		specDesc = registry.GetStrFromMap(spec, "description")
	}

	// Find existing service command or create one
	var svc *cobra.Command
	for _, c := range parent.Commands() {
		if c.Name() == specName {
			svc = c
			break
		}
	}
	if svc == nil {
		svc = &cobra.Command{
			Use:   specName,
			Short: specDesc,
		}
		parent.AddCommand(svc)
	}

	for resName, resource := range resources {
		resMap, _ := resource.(map[string]interface{})
		if resMap == nil {
			continue
		}
		registerResourceWithContext(ctx, svc, spec, resName, resMap, f)
	}
}

func registerResourceWithContext(ctx context.Context, parent *cobra.Command, spec map[string]interface{}, name string, resource map[string]interface{}, f *cmdutil.Factory) {
	res := &cobra.Command{
		Use:   name,
		Short: name + " operations",
	}
	parent.AddCommand(res)

	methods, _ := resource["methods"].(map[string]interface{})
	for methodName, method := range methods {
		methodMap, _ := method.(map[string]interface{})
		if methodMap == nil {
			continue
		}
		registerMethodWithContext(ctx, res, spec, methodMap, methodName, name, f)
	}
}

// ServiceMethodOptions holds all inputs for a dynamically registered service method command.
type ServiceMethodOptions struct {
	Factory    *cmdutil.Factory
	Cmd        *cobra.Command
	Ctx        context.Context
	Spec       map[string]interface{}
	Method     map[string]interface{}
	SchemaPath string

	// Flags
	Params     string
	Data       string
	As         core.Identity
	Output     string
	PageAll    bool
	PageLimit  int
	PageDelay  int
	Format     string
	JqExpr     string
	DryRun     bool
	File       string   // --file flag value
	FileFields []string // auto-detected file field names from metadata
}

// detectFileFields delegates to the shared cmdutil.DetectFileFields helper.
func detectFileFields(method map[string]interface{}) []string {
	return cmdutil.DetectFileFields(method)
}

func registerMethodWithContext(ctx context.Context, parent *cobra.Command, spec map[string]interface{}, method map[string]interface{}, name string, resName string, f *cmdutil.Factory) {
	parent.AddCommand(NewCmdServiceMethodWithContext(ctx, f, spec, method, name, resName, nil))
}

// NewCmdServiceMethod creates a command for a dynamically registered service method.
func NewCmdServiceMethod(f *cmdutil.Factory, spec, method map[string]interface{}, name, resName string, runF func(*ServiceMethodOptions) error) *cobra.Command {
	return NewCmdServiceMethodWithContext(context.Background(), f, spec, method, name, resName, runF)
}

func NewCmdServiceMethodWithContext(ctx context.Context, f *cmdutil.Factory, spec, method map[string]interface{}, name, resName string, runF func(*ServiceMethodOptions) error) *cobra.Command {
	desc := registry.GetStrFromMap(method, "description")
	httpMethod := registry.GetStrFromMap(method, "httpMethod")
	risk := registry.GetStrFromMap(method, "risk")
	specName := registry.GetStrFromMap(spec, "name")
	schemaPath := fmt.Sprintf("%s.%s.%s", specName, resName, name)

	opts := &ServiceMethodOptions{
		Factory:    f,
		Spec:       spec,
		Method:     method,
		SchemaPath: schemaPath,
	}
	var asStr string

	cmd := &cobra.Command{
		Use:   name,
		Short: desc,
		Long:  fmt.Sprintf("%s\n\nView parameter definitions before calling:\n  lark-cli schema %s", desc, schemaPath),
		RunE: func(cmd *cobra.Command, args []string) error {
			opts.Cmd = cmd
			opts.Ctx = cmd.Context()
			opts.As = core.Identity(asStr)
			if runF != nil {
				return runF(opts)
			}
			return serviceMethodRun(opts)
		},
	}

	cmd.Flags().StringVar(&opts.Params, "params", "", "URL/query parameters JSON (supports - for stdin, @file for file input)")
	switch httpMethod {
	case "POST", "PUT", "PATCH", "DELETE":
		cmd.Flags().StringVar(&opts.Data, "data", "", "request body JSON (supports - for stdin, @file for file input)")
	}
	cmdutil.AddAPIIdentityFlag(ctx, cmd, f, &asStr)
	cmd.Flags().StringVarP(&opts.Output, "output", "o", "", "output file path for binary responses")
	cmd.Flags().BoolVar(&opts.PageAll, "page-all", false, "automatically paginate through all pages")
	cmd.Flags().IntVar(&opts.PageLimit, "page-limit", 10, "max pages to fetch with --page-all (0 = unlimited)")
	cmd.Flags().IntVar(&opts.PageDelay, "page-delay", 200, "delay in ms between pages")
	cmd.Flags().StringVar(&opts.Format, "format", "json", "output format: json|ndjson|table|csv")
	cmd.Flags().StringVarP(&opts.JqExpr, "jq", "q", "", "jq expression to filter JSON output")
	cmd.Flags().BoolVar(&opts.DryRun, "dry-run", false, "print request without executing")
	if risk == "high-risk-write" {
		cmd.Flags().Bool("yes", false, "confirm high-risk operation")
	}

	// Conditionally register --file for methods with file-type fields.
	fileFields := detectFileFields(method)
	opts.FileFields = fileFields
	if len(fileFields) > 0 {
		switch httpMethod {
		case "POST", "PUT", "PATCH", "DELETE":
			cmd.Flags().StringVar(&opts.File, "file", "", "file to upload ([field=]path, supports - for stdin)")
		}
	}
	cmdutil.RegisterFlagCompletion(cmd, "format", func(_ *cobra.Command, _ []string, _ string) ([]string, cobra.ShellCompDirective) {
		return []string{"json", "ndjson", "table", "csv"}, cobra.ShellCompDirectiveNoFileComp
	})

	cmdutil.SetTips(cmd, registry.GetStrSliceFromMap(method, "tips"))
	cmdutil.SetRisk(cmd, risk)
	if tokens, ok := method["accessTokens"].([]interface{}); ok && len(tokens) > 0 {
		cmdutil.SetSupportedIdentities(cmd, cmdutil.AccessTokensToIdentities(tokens))
	}

	return cmd
}

func serviceMethodRun(opts *ServiceMethodOptions) error {
	f := opts.Factory
	opts.As = f.ResolveAs(opts.Ctx, opts.Cmd, opts.As)

	if err := f.CheckStrictMode(opts.Ctx, opts.As); err != nil {
		return err
	}

	// Check if this API method supports the resolved identity.
	if tokens, ok := opts.Method["accessTokens"].([]interface{}); ok && len(tokens) > 0 {
		if err := f.CheckIdentity(opts.As, cmdutil.AccessTokensToIdentities(tokens)); err != nil {
			return err
		}
	}

	if opts.PageAll && opts.Output != "" {
		return errs.NewValidationError(errs.SubtypeInvalidArgument, "--output and --page-all are mutually exclusive").WithParam("--output")
	}
	if err := output.ValidateJqFlags(opts.JqExpr, opts.Output, opts.Format); err != nil {
		return err
	}

	config, err := f.Config()
	if err != nil {
		return err
	}
	// Identity info is now included in the JSON envelope; skip stderr printing.
	// cmdutil.PrintIdentity(f.IOStreams.ErrOut, opts.As, config, f.IdentityAutoDetected)

	scopes, _ := opts.Method["scopes"].([]interface{})
	if !opts.As.IsBot() {
		if err := checkServiceScopes(opts.Ctx, f.Credential, opts.As, config, opts.Method, scopes); err != nil {
			return err
		}
	}

	request, fileMeta, err := buildServiceRequest(opts)
	if err != nil {
		return err
	}

	if opts.DryRun {
		if fileMeta != nil {
			return cmdutil.PrintDryRunWithFile(f.IOStreams.Out, request, config, opts.Format, fileMeta.FieldName, fileMeta.FilePath, fileMeta.FormFields)
		}
		return serviceDryRun(f, request, config, opts.Format)
	}

	if registry.GetStrFromMap(opts.Method, "risk") == "high-risk-write" {
		if yes, _ := opts.Cmd.Flags().GetBool("yes"); !yes {
			return cmdutil.RequireConfirmation(opts.SchemaPath)
		}
	}

	ac, err := f.NewAPIClientWithConfig(config)
	if err != nil {
		return err
	}

	out := f.IOStreams.Out
	format, formatOK := output.ParseFormat(opts.Format)
	if !formatOK {
		fmt.Fprintf(f.IOStreams.ErrOut, "warning: unknown format %q, falling back to json\n", opts.Format)
	}

	// Scope-insufficient (99991679) and all other Lark API codes route through
	// errclass.BuildAPIError via ac.CheckResponse, producing *errs.PermissionError
	// with MissingScopes / Identity / ConsoleURL populated from the response.
	checkErr := ac.CheckResponse

	if opts.PageAll {
		return servicePaginate(opts.Ctx, ac, request, format, opts.JqExpr, out, f.IOStreams.ErrOut,
			client.PaginationOptions{PageLimit: opts.PageLimit, PageDelay: opts.PageDelay}, checkErr)
	}

	resp, err := ac.DoAPI(opts.Ctx, request)
	if err != nil {
		return err
	}
	return client.HandleResponse(resp, client.ResponseOptions{
		OutputPath:  opts.Output,
		Format:      format,
		JqExpr:      opts.JqExpr,
		Out:         out,
		ErrOut:      f.IOStreams.ErrOut,
		FileIO:      f.ResolveFileIO(opts.Ctx),
		CommandPath: opts.Cmd.CommandPath(),
		Identity:    opts.As,
		CheckError:  checkErr,
	})
}

// checkServiceScopes pre-checks user scopes before making the API call.
func checkServiceScopes(ctx context.Context, cred *credential.CredentialProvider, identity core.Identity, config *core.CliConfig, method map[string]interface{}, scopes []interface{}) error {
	if ctx.Err() != nil {
		return ctx.Err()
	}
	result, err := cred.ResolveToken(ctx, credential.NewTokenSpec(identity, config.AppID))
	if err != nil || result == nil || result.Scopes == "" {
		return nil //nolint:nilerr // skip scope check when token resolution fails or has no scopes
	}

	requiredScopes, hasRequired := method["requiredScopes"].([]interface{})

	if hasRequired && len(requiredScopes) > 0 {
		// Strict: ALL requiredScopes must be present
		required := make([]string, 0, len(requiredScopes))
		for _, s := range requiredScopes {
			if str, ok := s.(string); ok {
				required = append(required, str)
			}
		}
		if missing := auth.MissingScopes(result.Scopes, required); len(missing) > 0 {
			return newPreflightMissingScopeError(string(config.Brand), config.AppID, string(identity), missing)
		}
		return nil
	}

	if len(scopes) == 0 {
		return nil
	}

	// Default: ANY one of the declared scopes is sufficient
	grantedSet := make(map[string]bool)
	for _, s := range strings.Fields(result.Scopes) {
		grantedSet[s] = true
	}
	for _, s := range scopes {
		if str, ok := s.(string); ok && grantedSet[str] {
			return nil
		}
	}
	recommended := registry.SelectRecommendedScope(scopes, "user")
	return newPreflightMissingScopeError(string(config.Brand), config.AppID, string(identity), []string{recommended})
}

// newPreflightMissingScopeError constructs a PermissionError for the local
// pre-flight scope check that converges byte-for-byte with the dispatcher's
// BuildAPIError path. Uses the canonical helpers in internal/errclass so
// Hint and Message stay in lock-step with the server-response classifier.
// ConsoleURL is deliberately omitted: the dispatcher only sets it for
// SubtypeAppScopeNotApplied (bot-perspective dev-action recovery), and this
// pre-flight path is user-perspective SubtypeMissingScope whose recovery is
// `lark-cli auth login --scope ...`, not a console deep-link.
func newPreflightMissingScopeError(brand, appID, identity string, missing []string) *errs.PermissionError {
	consoleURL := errclass.ConsoleURL(brand, appID, missing)
	return errs.NewPermissionError(errs.SubtypeMissingScope,
		"%s", errclass.CanonicalPermissionMessage(errs.SubtypeMissingScope, appID, missing, "")).
		WithHint("%s", errclass.PermissionHint(missing, identity, errs.SubtypeMissingScope, consoleURL)).
		WithMissingScopes(missing...).
		WithIdentity(identity)
}

// buildServiceRequest parses flags, builds the URL with path/query params, and returns a RawApiRequest.
// When dryRun is true and a file is provided, file reading is skipped and
// FileUploadMeta is returned instead so the caller can render dry-run output.
func buildServiceRequest(opts *ServiceMethodOptions) (client.RawApiRequest, *cmdutil.FileUploadMeta, error) {
	spec := opts.Spec
	method := opts.Method
	schemaPath := opts.SchemaPath
	httpMethod := registry.GetStrFromMap(method, "httpMethod")

	// stdin is an io.Reader consumed at most once. Only one of --params/--data
	// may use "-" (stdin); the conflict check below prevents silent data loss.
	stdin := opts.Factory.IOStreams.In
	fileIO := opts.Factory.ResolveFileIO(opts.Ctx)

	// Validate --file mutual exclusions.
	if err := cmdutil.ValidateFileFlag(opts.File, opts.Params, opts.Data, opts.Output, opts.PageAll, httpMethod); err != nil {
		return client.RawApiRequest{}, nil, err
	}
	if opts.Params == "-" && opts.Data == "-" {
		return client.RawApiRequest{}, nil, errs.NewValidationError(errs.SubtypeInvalidArgument, "--params and --data cannot both read from stdin (-)").WithParam("--params")
	}
	params, err := cmdutil.ParseJSONMap(opts.Params, "--params", stdin, fileIO)
	if err != nil {
		return client.RawApiRequest{}, nil, err
	}

	url := registry.GetStrFromMap(spec, "servicePath") + "/" + registry.GetStrFromMap(method, "path")

	parameters, _ := method["parameters"].(map[string]interface{})
	for name, param := range parameters {
		p, _ := param.(map[string]interface{})
		if registry.GetStrFromMap(p, "location") != "path" {
			continue
		}
		val, ok := params[name]
		if !ok || util.IsEmptyValue(val) {
			return client.RawApiRequest{}, nil, errs.NewValidationError(errs.SubtypeInvalidArgument,
				"missing required path parameter: %s", name).
				WithHint("lark-cli schema %s", schemaPath).
				WithParam(name)
		}
		valStr := fmt.Sprintf("%v", val)
		if err := validate.ResourceName(valStr, name); err != nil {
			return client.RawApiRequest{}, nil, errs.NewValidationError(errs.SubtypeInvalidArgument, "%s", err).WithParam(name).WithCause(err)
		}
		url = strings.Replace(url, "{"+name+"}", validate.EncodePathSegment(valStr), 1)
		delete(params, name)
	}

	queryParams := map[string]interface{}{}
	for name, param := range parameters {
		p, _ := param.(map[string]interface{})
		if registry.GetStrFromMap(p, "location") != "query" {
			continue
		}
		value, exists := params[name]
		required, _ := p["required"].(bool)
		isPaginationParam := opts.PageAll && (name == "page_token" || name == "page_size")
		if required && !isPaginationParam && (!exists || util.IsEmptyValue(value)) {
			return client.RawApiRequest{}, nil, errs.NewValidationError(errs.SubtypeInvalidArgument,
				"missing required query parameter: %s", name).
				WithHint("lark-cli schema %s", schemaPath).
				WithParam(name)
		}
		if exists && !util.IsEmptyValue(value) {
			queryParams[name] = value
		}
	}
	for name, value := range params {
		if _, ok := queryParams[name]; !ok {
			queryParams[name] = value
		}
	}

	request := client.RawApiRequest{
		Method: httpMethod,
		URL:    url,
		Params: queryParams,
		As:     opts.As,
	}

	if opts.File != "" {
		// File upload: determine default field name from metadata.
		defaultField := "file"
		if len(opts.FileFields) == 1 {
			defaultField = opts.FileFields[0]
		}
		fieldName, filePath, isStdin := cmdutil.ParseFileFlag(opts.File, defaultField)

		// Parse --data as form fields.
		var dataFields any
		if opts.Data != "" {
			dataFields, err = cmdutil.ParseOptionalBody(httpMethod, opts.Data, stdin, fileIO)
			if err != nil {
				return client.RawApiRequest{}, nil, err
			}
			if _, ok := dataFields.(map[string]any); !ok {
				return client.RawApiRequest{}, nil, errs.NewValidationError(errs.SubtypeInvalidArgument, "--data must be a JSON object when used with --file").WithParam("--data")
			}
		}

		if opts.DryRun {
			return request, &cmdutil.FileUploadMeta{
				FieldName: fieldName, FilePath: filePath, FormFields: dataFields,
			}, nil
		}

		fd, err := cmdutil.BuildFormdata(
			fileIO,
			fieldName, filePath, isStdin, stdin, dataFields,
		)
		if err != nil {
			return client.RawApiRequest{}, nil, err
		}
		request.Data = fd
		request.ExtraOpts = append(request.ExtraOpts, larkcore.WithFileUpload())
	} else {
		data, err := cmdutil.ParseOptionalBody(httpMethod, opts.Data, stdin, fileIO)
		if err != nil {
			return client.RawApiRequest{}, nil, err
		}
		request.Data = data
		if opts.Output != "" {
			request.ExtraOpts = append(request.ExtraOpts, larkcore.WithFileDownload())
		}
	}

	return request, nil, nil
}

func serviceDryRun(f *cmdutil.Factory, request client.RawApiRequest, config *core.CliConfig, format string) error {
	return cmdutil.PrintDryRun(f.IOStreams.Out, request, config, format)
}

func servicePaginate(ctx context.Context, ac *client.APIClient, request client.RawApiRequest, format output.Format, jqExpr string, out, errOut io.Writer, pagOpts client.PaginationOptions, checkErr func(interface{}, core.Identity) error) error {
	if pagOpts.Identity == "" {
		pagOpts.Identity = request.As
	}
	// When jq is set, always aggregate all pages then filter.
	if jqExpr != "" {
		return client.PaginateWithJq(ctx, ac, request, jqExpr, out, pagOpts, checkErr)
	}

	switch format {
	case output.FormatNDJSON, output.FormatTable, output.FormatCSV:
		pf := output.NewPaginatedFormatter(out, format)
		result, hasItems, err := ac.StreamPages(ctx, request, func(items []interface{}) {
			pf.FormatPage(items)
		}, pagOpts)
		if err != nil {
			return err
		}
		if apiErr := checkErr(result, pagOpts.Identity); apiErr != nil {
			return apiErr
		}
		if !hasItems {
			fmt.Fprintf(errOut, "warning: this API does not return a list, format %q is not supported, falling back to json\n", format)
			output.FormatValue(out, result, output.FormatJSON)
		}
		return nil
	default:
		result, err := ac.PaginateAll(ctx, request, pagOpts)
		if err != nil {
			return err
		}
		if apiErr := checkErr(result, pagOpts.Identity); apiErr != nil {
			return apiErr
		}
		output.FormatValue(out, result, format)
		return nil
	}
}