package ckconfig

import (
	"bytes"
	"fmt"
	"io"
	"strings"

	commandkit "gitea.maximumdirect.net/eric/CommandKit"
	"go.yaml.in/yaml/v4"
)

func runConfigValidation[I, S any](invocation commandkit.Invocation, plan *configOperationPlan[I, S], state S) commandkit.Outcome {
	reporter := invocation.Reporter()
	writtenRecord := false
	for _, selected := range plan.scopes {
		if err := invocation.Context.Err(); err != nil {
			return configFailure("Configuration validation was canceled.", commandkit.Explanation{}, err)
		}
		if selected.scope.scope.Acquire == nil {
			message := fmt.Sprintf("Configuration scope %q has no acquisition callback.", selected.scope.scope.Name)
			return commandkit.Failure(message)
		}
		acquired, acquireErr := selected.scope.scope.Acquire(invocation.Context, Request{
			Operation: Validate,
			Selection: plan.selection,
		}, selected.input, state)
		if acquireErr != nil {
			return configAcquisitionFailure(reporter, "validate", selected.scope.scope.Name, acquired, acquireErr)
		}
		queueConfigDiagnostics(reporter, acquired.Diagnostics)
		if err := invocation.Context.Err(); err != nil {
			return configFailure("Configuration validation was canceled.", acquired.Explanation, err)
		}

		err := reporter.RenderOutput(func(writer io.Writer) error {
			record, err := validationSuccessRecord(selected.scope.scope.Name, plan.format)
			if err != nil {
				return err
			}
			if plan.format == "yaml" && !writtenRecord {
				if _, err := io.WriteString(writer, "scopes:\n"); err != nil {
					return err
				}
			}
			_, err = writer.Write(record)
			return err
		})
		if err != nil {
			if ctxErr := invocation.Context.Err(); ctxErr != nil {
				return configFailure("Configuration validation was canceled.", acquired.Explanation, ctxErr)
			}
			return commandkit.Success()
		}
		writtenRecord = true
	}
	return commandkit.Success()
}

func validationSuccessRecord(scope, format string) ([]byte, error) {
	if format == "text" {
		return []byte(scope + ": valid\n"), nil
	}
	encoded, err := yaml.Marshal(struct {
		Name  string `yaml:"name"`
		Valid bool   `yaml:"valid"`
	}{Name: scope, Valid: true})
	if err != nil {
		return nil, err
	}
	lines := strings.Split(strings.TrimSuffix(string(encoded), "\n"), "\n")
	var record bytes.Buffer
	for index, line := range lines {
		if index == 0 {
			record.WriteString("  - ")
		} else {
			record.WriteString("    ")
		}
		record.WriteString(line)
		record.WriteByte('\n')
	}
	return record.Bytes(), nil
}