package ckconfig

import (
	"bytes"
	"fmt"
	"io"

	commandkit "go.maximumdirect.net/commandkit"
)

type effectiveDocument struct {
	name string
	view View
}

func runConfigShow[I, S any](invocation commandkit.Invocation, plan *configOperationPlan[I, S], state S) commandkit.Outcome {
	documents := make([]effectiveDocument, 0, len(plan.scopes))
	reporter := invocation.Reporter()
	for _, selected := range plan.scopes {
		if err := invocation.Context.Err(); err != nil {
			return configFailure("Configuration show was canceled.", commandkit.Explanation{}, err)
		}
		if selected.scope.scope.Acquire == nil {
			return commandkit.Failure(fmt.Sprintf("Configuration scope %q has no acquisition callback.", selected.scope.scope.Name))
		}
		acquired, acquireErr := selected.scope.scope.Acquire(invocation.Context, Request{Operation: Show, Selection: plan.selection}, selected.input, state)
		if acquireErr != nil {
			return configAcquisitionFailure(reporter, "show", selected.scope.scope.Name, acquired, acquireErr)
		}
		queueConfigDiagnostics(reporter, acquired.Diagnostics)
		if err := invocation.Context.Err(); err != nil {
			return configFailure("Configuration show was canceled.", acquired.Explanation, err)
		}
		if acquired.Value.Effective == nil {
			return commandkit.Failure(fmt.Sprintf("Configuration scope %q did not provide an effective configuration writer.", selected.scope.scope.Name))
		}
		documents = append(documents, effectiveDocument{name: selected.scope.scope.Name, view: acquired.Value})
	}
	if err := invocation.Context.Err(); err != nil {
		return configFailure("Configuration show was canceled.", commandkit.Explanation{}, err)
	}
	var value any
	err := reporter.RenderOutput(func(io.Writer) error {
		values := make(map[string]any, len(documents))
		for _, document := range documents {
			if err := invocation.Context.Err(); err != nil {
				return err
			}
			var native bytes.Buffer
			if err := document.view.Effective.WriteEffective(&native); err != nil {
				return err
			}
			decoded, err := commandkit.DecodeYAMLReport(&native)
			if err != nil {
				return err
			}
			values[document.name] = decoded
		}
		if plan.scopeName == "all" {
			value = values
		} else {
			value = values[documents[0].name]
		}
		return nil
	})
	if err != nil {
		if canceled := invocation.Context.Err(); canceled != nil {
			return configFailure("Configuration show was canceled.", commandkit.Explanation{}, canceled)
		}
		return commandkit.Success()
	}
	if err := invocation.Context.Err(); err != nil {
		return configFailure("Configuration show was canceled.", commandkit.Explanation{}, err)
	}
	_ = reporter.Report(commandkit.Report{Value: value})
	return commandkit.Success()
}