package vset

import (
	"encoding/json"
	"fmt"
	"os"

	"edge-infra.dev/pkg/lib/build/bazel"
)

// The Configure interface contains Configurator(), which guides the file through the configuration functions.
// Each configuration function sets its respective field of settings.json to the desired value.
// Fields that require structs as values have struct declarations in structs.go.
type Configure interface {
	Configurator(string) error
	FileAssociations(...interface{}) map[string]interface{}
	FileWatcherExclude(...interface{}) map[string]interface{}
	GoAltTools() map[string]string
	GoLintFlags() []string
	Gopls(...interface{}) map[string]interface{}
	JSONConfig(...interface{}) map[string]interface{}
	StarlarkConfig(...interface{}) map[string]interface{}
}

func Configurator(path, goLintPath string) error {
	byteValue, err := os.ReadFile(path)
	if err != nil {
		return fmt.Errorf("failed to read existing settings.json: %w", err)
	}
	// Settings.json is Unmarshaled into settingsMap to be configured.
	var settingsMap map[string]interface{}
	if err = json.Unmarshal(byteValue, &settingsMap); err != nil {
		return fmt.Errorf("failed to unmarshal json, confirm that your settings.json is free of syntax errors: %w", err)
	}

	// Update settingsMap to reflect the correct settings for each field.
	settingsMap["[json]"] = JSONConfig(settingsMap["[json]"])
	settingsMap["[starlark]"] = StarlarkConfig(settingsMap["[starlark]"])
	settingsMap["bazel.buildifierFixOnFormat"] = true
	settingsMap["files.associations"] = FileAssociations(settingsMap["files.associations"])
	settingsMap["files.watcherExclude"] = FileWatcherExclude(settingsMap["files.watcherExclude"])
	settingsMap["go.lintFlags"] = GoLintFlags(goLintPath)
	settingsMap["go.lintOnSave"] = "package"
	settingsMap["go.lintTool"] = "golangci-lint"
	settingsMap["go.useLanguageServer"] = true
	settingsMap["gopls"] = Gopls(settingsMap["gopls"])
	settingsMap["go.alternateTools"], err = GoAltTools()
	if err != nil {
		return err
	}

	// After configuration is complete, convert settingsMap back to json and write it to settings.json.
	byteValue, err = json.MarshalIndent(settingsMap, "", "	")
	if err != nil {
		return fmt.Errorf("failed to marshal json: %w", err)
	}
	if err = os.WriteFile(path, byteValue, 0644); err != nil {
		return fmt.Errorf("failed to rewrite settings.json: %w", err)
	}
	fmt.Println("...settings.json configured successfully!")
	fmt.Println("For more customization, see https://github.com/golang/vscode-go/blob/master/docs/settings.md")
	fmt.Println("Exiting...")
	return nil
}

func FileAssociations(fileSet ...interface{}) map[string]interface{} {
	fileMap := make(map[string]interface{})
	if fileSet[0] != nil {
		fileMap = fileSet[0].(map[string]interface{})
	}
	fileMap[".warehouse-dist/**/*"] = "json"
	return fileMap
}

func FileWatcherExclude(excludeSet ...interface{}) map[string]interface{} {
	excludeMap := make(map[string]interface{})
	if excludeSet[0] != nil {
		excludeMap = excludeSet[0].(map[string]interface{})
	}
	excludeMap["**/.git/objects/**"] = true
	excludeMap["**/.git/subtree-cache/**"] = true
	excludeMap["**/.warehouse-dist/**"] = true
	excludeMap["**/node_modules/*/**"] = true
	excludeMap["**/bazel-bin/*/**"] = true
	excludeMap["**/bazel-edge-infra/*/**"] = true
	excludeMap["**/bazel-out/*/**"] = true
	excludeMap["**/bazel-testlogs/*/**"] = true
	return excludeMap
}

func GoAltTools() (map[string]string, error) {
	goPath, err := bazel.FindRepoRoot(path)
	if err != nil {
		return nil, fmt.Errorf("failed to find repo root: %w", err)
	}
	goPath += "/bazel-edge-infra/external/go_sdk/bin/go"
	return map[string]string{
		"go": goPath,
	}, nil
}

func GoLintFlags(goLintPath string) []string {
	return []string{
		"--fast",
		"-c",
		goLintPath + "hack/tools/linters/golangcilint.yaml",
	}
}

func Gopls(goplsSet ...interface{}) map[string]interface{} {
	goplsMap := make(map[string]interface{})
	if goplsSet[0] != nil {
		goplsMap = goplsSet[0].(map[string]interface{})
	}
	goplsMap["build.directoryFilters"] = []string{
		"-bazel-bin",
		"-bazel-edge-infra",
		"-bazel-out",
		"-bazel-testlogs",
	}
	goplsMap["formatting.local"] = "edge-infra.dev"
	// Delete problematic personal configs if present
	if _, exists := goplsMap["build.experimentalWorkspaceModule"]; exists {
		fmt.Println("WARNING: gopls:build.experimentalWorkspaceModule can be problematic and has been deleted.")
		delete(goplsMap, "build.experimentalWorkspaceModule")
	}
	return goplsMap
}

func JSONConfig(jsonSet ...interface{}) map[string]interface{} {
	jsonMap := make(map[string]interface{})
	if jsonSet[0] != nil {
		jsonMap = jsonSet[0].(map[string]interface{})
	}
	jsonMap["editor.formatOnSave"] = true
	jsonMap["editor.defaultFormatter"] = "vscode.json-language-features"
	return jsonMap
}

func StarlarkConfig(starlarkSet ...interface{}) map[string]interface{} {
	starlarkMap := make(map[string]interface{})
	if starlarkSet[0] != nil {
		starlarkMap = starlarkSet[0].(map[string]interface{})
	}
	starlarkMap["editor.formatOnSave"] = true
	starlarkMap["editor.tabSize"] = 4
	return starlarkMap
}