// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package fake

import (
	"context"

	"golang.org/x/tools/internal/lsp/protocol"
)

// Client is an adapter that converts an *Editor into an LSP Client. It mosly
// delegates functionality to hooks that can be configured by tests.
type Client struct {
	*Editor

	// Hooks for testing. Add additional hooks here as needed for testing.
	onLogMessage             func(context.Context, *protocol.LogMessageParams) error
	onDiagnostics            func(context.Context, *protocol.PublishDiagnosticsParams) error
	onWorkDoneProgressCreate func(context.Context, *protocol.WorkDoneProgressCreateParams) error
	onProgress               func(context.Context, *protocol.ProgressParams) error
}

// OnLogMessage sets the hook to run when the editor receives a log message.
func (c *Client) OnLogMessage(hook func(context.Context, *protocol.LogMessageParams) error) {
	c.mu.Lock()
	c.onLogMessage = hook
	c.mu.Unlock()
}

// OnDiagnostics sets the hook to run when the editor receives diagnostics
// published from the language server.
func (c *Client) OnDiagnostics(hook func(context.Context, *protocol.PublishDiagnosticsParams) error) {
	c.mu.Lock()
	c.onDiagnostics = hook
	c.mu.Unlock()
}

func (c *Client) OnWorkDoneProgressCreate(hook func(context.Context, *protocol.WorkDoneProgressCreateParams) error) {
	c.mu.Lock()
	c.onWorkDoneProgressCreate = hook
	c.mu.Unlock()
}

func (c *Client) OnProgress(hook func(context.Context, *protocol.ProgressParams) error) {
	c.mu.Lock()
	c.onProgress = hook
	c.mu.Unlock()
}

func (c *Client) ShowMessage(ctx context.Context, params *protocol.ShowMessageParams) error {
	c.mu.Lock()
	c.lastMessage = params
	c.mu.Unlock()
	return nil
}

func (c *Client) ShowMessageRequest(ctx context.Context, params *protocol.ShowMessageRequestParams) (*protocol.MessageActionItem, error) {
	return nil, nil
}

func (c *Client) LogMessage(ctx context.Context, params *protocol.LogMessageParams) error {
	c.mu.Lock()
	c.logs = append(c.logs, params)
	onLogMessage := c.onLogMessage
	c.mu.Unlock()
	if onLogMessage != nil {
		return onLogMessage(ctx, params)
	}
	return nil
}

func (c *Client) Event(ctx context.Context, event *interface{}) error {
	c.mu.Lock()
	c.events = append(c.events, event)
	c.mu.Unlock()
	return nil
}

func (c *Client) PublishDiagnostics(ctx context.Context, params *protocol.PublishDiagnosticsParams) error {
	c.mu.Lock()
	c.diagnostics = params
	onPublishDiagnostics := c.onDiagnostics
	c.mu.Unlock()
	if onPublishDiagnostics != nil {
		return onPublishDiagnostics(ctx, params)
	}
	return nil
}

func (c *Client) WorkspaceFolders(context.Context) ([]protocol.WorkspaceFolder, error) {
	return []protocol.WorkspaceFolder{}, nil
}

func (c *Client) Configuration(_ context.Context, p *protocol.ParamConfiguration) ([]interface{}, error) {
	results := make([]interface{}, len(p.Items))
	for i, item := range p.Items {
		if item.Section != "gopls" {
			continue
		}
		results[i] = c.configuration()
	}
	return results, nil
}

func (c *Client) RegisterCapability(context.Context, *protocol.RegistrationParams) error {
	return nil
}

func (c *Client) UnregisterCapability(context.Context, *protocol.UnregistrationParams) error {
	return nil
}

func (c *Client) Progress(ctx context.Context, params *protocol.ProgressParams) error {
	c.mu.Lock()
	onProgress := c.onProgress
	c.mu.Unlock()
	if onProgress != nil {
		return onProgress(ctx, params)
	}
	return nil
}

func (c *Client) WorkDoneProgressCreate(ctx context.Context, params *protocol.WorkDoneProgressCreateParams) error {
	c.mu.Lock()
	onCreate := c.onWorkDoneProgressCreate
	c.mu.Unlock()
	if onCreate != nil {
		return onCreate(ctx, params)
	}
	return nil
}

// ApplyEdit applies edits sent from the server. Note that as of writing gopls
// doesn't use this feature, so it is untested.
func (c *Client) ApplyEdit(ctx context.Context, params *protocol.ApplyWorkspaceEditParams) (*protocol.ApplyWorkspaceEditResponse, error) {
	if len(params.Edit.Changes) != 0 {
		return &protocol.ApplyWorkspaceEditResponse{FailureReason: "Edit.Changes is unsupported"}, nil
	}
	for _, change := range params.Edit.DocumentChanges {
		path := c.ws.URIToPath(change.TextDocument.URI)
		edits := convertEdits(change.Edits)
		c.EditBuffer(ctx, path, edits)
	}
	return &protocol.ApplyWorkspaceEditResponse{Applied: true}, nil
}