package ckconfig

import (
	"bytes"
	"context"
	"encoding/json"
	"io"
	"strings"
	"testing"

	commandkit "go.maximumdirect.net/commandkit"
	configkit "go.maximumdirect.net/configkit"
)

func TestExplainDiscoveryModesAndMetadata(t *testing.T) {
	loads, inputs, states := 0, 0, 0
	scope := FromConfigKit("app", "", func(_ context.Context, selection Selection, _, _ struct{}) (*configkit.Result[map[string]any], error) {
		loads++
		return configkit.Load(configkit.Mapping("fixture", map[string]any{"a/b": map[string]any{"x": 1}, "ab": 2, "abacus": 3, "gone": map[string]any{"x": 1}}), configkit.Options[map[string]any]{Overrides: selection.Overrides})
	})
	scope.Features.Overrides = true
	app := newConfigTestApp(t, Command(Suite[struct{}, struct{}]{NewInput: func() struct{} { inputs++; return struct{}{} }, NewState: func() struct{} { states++; return struct{}{} }, Scopes: []Scope[struct{}, struct{}]{scope}}))
	run := func(args ...string) (commandkit.Outcome, string) {
		var out bytes.Buffer
		result := app.Execute(context.Background(), append([]string{"config", "explain"}, args...), commandkit.Streams{Out: &out, Err: io.Discard})
		return result, out.String()
	}
	result, out := run()
	if result.Kind != commandkit.OutcomeSuccess || !strings.Contains(out, "--list") || !strings.Contains(out, "--path") || loads != 0 || inputs != 0 || states != 0 {
		t.Fatalf("bare help: %#v %q, %d/%d/%d", result, out, loads, inputs, states)
	}
	for _, args := range [][]string{{"--list", "--path=/ab"}, {"--historical"}, {"--under=/ab"}, {"--explicit=false"}, {"--path=/ab", "--under=/ab"}, {"--list", "--under=bad"}} {
		result, _ := run(args...)
		if result.Kind != commandkit.OutcomeUsage || loads != 0 || inputs != 0 || states != 0 {
			t.Fatalf("invalid %v: %#v, %d/%d/%d", args, result, loads, inputs, states)
		}
	}
	result, out = run("--list", "--under=/a~1b", "--format=json")
	var report pathDiscoveryReport
	if result.Kind != commandkit.OutcomeSuccess || json.Unmarshal([]byte(out), &report) != nil || len(report.Paths) != 2 {
		t.Fatalf("escaped subtree: %#v %q", result, out)
	}
	seen := map[string]bool{}
	for _, entry := range report.Paths {
		seen[entry.Path] = true
	}
	if !seen["/a~1b"] || !seen["/a~1b/x"] {
		t.Fatalf("escaped paths: %#v", report.Paths)
	}
	result, out = run("--list", "--under=/ab", "--format=json")
	if result.Kind != commandkit.OutcomeSuccess || json.Unmarshal([]byte(out), &report) != nil || len(report.Paths) != 1 || report.Paths[0].Path != "/ab" {
		t.Fatalf("token boundary: %#v %q", result, out)
	}
	result, out = run("--list", "--historical", "--set=/gone=null", "--format=json")
	if result.Kind != commandkit.OutcomeSuccess || json.Unmarshal([]byte(out), &report) != nil {
		t.Fatalf("historical: %#v %q", result, out)
	}
	removed := false
	for _, entry := range report.Paths {
		if entry.Path == "/gone/x" && !entry.Present && entry.Metadata == nil {
			removed = true
		}
	}
	if !removed {
		t.Fatalf("missing historical entry: %q", out)
	}
	result, out = run("--list", "--historical", "--explicit=false", "--set=/gone=null", "--format=json")
	if result.Kind != commandkit.OutcomeSuccess || json.Unmarshal([]byte(out), &report) != nil {
		t.Fatalf("explicit filter: %#v %q", result, out)
	}
	for _, entry := range report.Paths {
		if !entry.Present || entry.Metadata == nil || entry.Metadata.Explicit {
			t.Fatalf("invalid filtered entry: %#v", entry)
		}
	}
	result, out = run("--path=", "--format=json")
	if result.Kind != commandkit.OutcomeSuccess || !strings.Contains(out, `"path": ""`) || !strings.Contains(out, `"metadata"`) {
		t.Fatalf("root explanation: %#v %q", result, out)
	}
	result, out = run("--path=/gone/x", "--set=/gone=null", "--format=json")
	if result.Kind != commandkit.OutcomeSuccess || !strings.Contains(out, `"metadata"`) || !strings.Contains(out, `"history"`) {
		t.Fatalf("historical explanation: %#v %q", result, out)
	}
}

func TestExplainDiscoveryCapabilityBeforeAcquisition(t *testing.T) {
	calls := 0
	scope := Scope[struct{}, struct{}]{Name: "app", Operations: []Operation{Explain}, Acquire: func(context.Context, Request, struct{}, struct{}) (commandkit.Acquired[View], error) {
		calls++
		return commandkit.Acquired[View]{}, nil
	}}
	app := newConfigTestApp(t, Command(Suite[struct{}, struct{}]{Scopes: []Scope[struct{}, struct{}]{scope}}))
	result := app.Execute(context.Background(), []string{"config", "explain", "--list"}, commandkit.Streams{Out: io.Discard, Err: io.Discard})
	if result.Kind != commandkit.OutcomeUsage || calls != 0 {
		t.Fatalf("unsupported discovery: %#v calls=%d", result, calls)
	}
	scope.Features.PathDiscovery = true
	app = newConfigTestApp(t, Command(Suite[struct{}, struct{}]{Scopes: []Scope[struct{}, struct{}]{scope}}))
	result = app.Execute(context.Background(), []string{"config", "explain", "--list"}, commandkit.Streams{Out: io.Discard, Err: io.Discard})
	if result.Kind != commandkit.OutcomeOperational || calls != 1 {
		t.Fatalf("missing metadata: %#v calls=%d", result, calls)
	}
}

func TestExplainBareHelpRecordsDeliveryFailure(t *testing.T) {
	inputs, states, calls := 0, 0, 0
	scope := Scope[struct{}, struct{}]{Name: "app", Operations: []Operation{Explain}, Acquire: func(context.Context, Request, struct{}, struct{}) (commandkit.Acquired[View], error) {
		calls++
		return commandkit.Acquired[View]{}, nil
	}}
	app := newConfigTestApp(t, Command(Suite[struct{}, struct{}]{NewInput: func() struct{} { inputs++; return struct{}{} }, NewState: func() struct{} { states++; return struct{}{} }, Scopes: []Scope[struct{}, struct{}]{scope}}))
	result := app.Execute(context.Background(), []string{"config", "explain"}, commandkit.Streams{Out: shortWriter{}, Err: io.Discard})
	if result.Presentation.Output.State != commandkit.DeliveryIncomplete || inputs != 0 || states != 0 || calls != 0 {
		t.Fatalf("help delivery = %#v, input/state/acquire=%d/%d/%d", result, inputs, states, calls)
	}
}