package ckconfig

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

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

func validationDiagnostic(message string) commandkit.Diagnostic {
	return commandkit.Diagnostic{Severity: commandkit.SeverityWarning, Write: func(w io.Writer) error { _, err := io.WriteString(w, message+"\n"); return err }}
}

func TestDetailedValidationFiltersAndRetainsFailureEvidence(t *testing.T) {
	cause := errors.New("second scope failed")
	calls := []string{}
	reader := &sourceInventory{values: []configkit.SourceInfo{{ID: "primary", Label: "main", Path: "main.yml"}, {ID: "related", Label: "included", Path: "include.yml"}, {ID: "unused", Label: "unused"}}}
	records := []configkit.Diagnostic{
		{Code: "chosen", Severity: configkit.SeverityWarning, Path: configkit.Keys("a/b"), Message: "selected warning", Primary: &configkit.Location{SourceID: "primary", Line: 2, Column: 3}, Related: []configkit.Location{{SourceID: "related", Line: 7, Column: 8}}},
		{Code: "other", Severity: configkit.SeverityWarning, Path: configkit.Keys("other"), Message: "other warning"},
	}
	scopes := []Scope[struct{}, struct{}]{
		{Name: "app", Operations: []Operation{Validate}, Acquire: func(context.Context, Request, struct{}, struct{}) (commandkit.Acquired[View], error) {
			calls = append(calls, "app")
			return commandkit.Acquired[View]{Value: View{Sources: reader, Findings: &Findings{Records: records, Messages: []commandkit.Diagnostic{validationDiagnostic("native warnings")}}}, Diagnostics: []commandkit.Diagnostic{validationDiagnostic("application warning")}}, nil
		}},
		{Name: "second", Operations: []Operation{Validate}, Acquire: func(context.Context, Request, struct{}, struct{}) (commandkit.Acquired[View], error) {
			calls = append(calls, "second")
			return commandkit.Acquired[View]{Value: View{Findings: &Findings{Records: []configkit.Diagnostic{{Code: "failed", Severity: configkit.SeverityError, Message: "failed finding"}}}}, Explanation: commandkit.Explanation{Message: "terminal failure"}}, cause
		}},
		{Name: "third", Operations: []Operation{Validate}, Acquire: func(context.Context, Request, struct{}, struct{}) (commandkit.Acquired[View], error) {
			calls = append(calls, "third")
			return commandkit.Acquired[View]{}, nil
		}},
	}
	app := newConfigTestApp(t, Command(Suite[struct{}, struct{}]{Scopes: scopes}))
	var out, diag bytes.Buffer
	result := app.Execute(context.Background(), []string{"config", "validate", "--scope=all", "--details", "--severity=warning", "--code=chosen", "--format=json", "--verbose"}, commandkit.Streams{Out: &out, Err: &diag})
	decoder := json.NewDecoder(&out)
	var report validationReport
	if err := decoder.Decode(&report); err != nil {
		t.Fatal(err)
	}
	if err := decoder.Decode(new(any)); err != io.EOF {
		t.Fatalf("extra JSON: %v", err)
	}
	if !errors.Is(result.Cause, cause) || result.Kind != commandkit.OutcomeOperational || len(calls) != 2 || calls[0] != "app" || calls[1] != "second" || len(report.Scopes) != 2 || report.Scopes[0].Outcome != "valid" || report.Scopes[1].Outcome != "failed" {
		t.Fatalf("result=%#v calls=%v report=%#v", result, calls, report)
	}
	first, second := report.Scopes[0].Details, report.Scopes[1].Details
	if first == nil || first.State != "present" || len(first.Findings) != 1 || first.Findings[0].Path != "/a~1b" || len(first.Sources) != 2 || first.Sources[0].ID != "primary" || first.Sources[1].ID != "related" || second == nil || second.State != "filtered" || len(second.Findings) != 0 {
		t.Fatalf("details=%#v %#v", first, second)
	}
	if strings.Contains(diag.String(), "native warnings") || !strings.Contains(diag.String(), "application warning") || !strings.Contains(diag.String(), "terminal failure") {
		t.Fatalf("diagnostics=%q", diag.String())
	}
	before := len(calls)
	for _, args := range [][]string{{"--severity=warning"}, {"--code=x"}, {"--details", "--severity=unknown"}} {
		result = app.Execute(context.Background(), append([]string{"config", "validate"}, args...), commandkit.Streams{Out: io.Discard, Err: io.Discard})
		if result.Kind != commandkit.OutcomeUsage || len(calls) != before {
			t.Fatalf("invalid %v: %#v", args, result)
		}
	}
}

func TestValidationCancellationAndDeliveryRetainReachedScopes(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	calls := 0
	scopes := []Scope[struct{}, struct{}]{
		{Name: "app", Operations: []Operation{Validate}, Acquire: func(context.Context, Request, struct{}, struct{}) (commandkit.Acquired[View], error) {
			calls++
			return commandkit.Acquired[View]{Value: View{Findings: &Findings{}}}, nil
		}},
		{Name: "second", Operations: []Operation{Validate}, Acquire: func(context.Context, Request, struct{}, struct{}) (commandkit.Acquired[View], error) {
			calls++
			cancel()
			return commandkit.Acquired[View]{}, nil
		}},
		{Name: "third", Operations: []Operation{Validate}, 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: scopes}))
	var out bytes.Buffer
	result := app.Execute(ctx, []string{"config", "validate", "--scope=all", "--details", "--format=json"}, commandkit.Streams{Out: &out, Err: io.Discard})
	var report validationReport
	if err := json.Unmarshal(out.Bytes(), &report); err != nil {
		t.Fatal(err)
	}
	if !errors.Is(result.Cause, context.Canceled) || calls != 2 || len(report.Scopes) != 2 || report.Scopes[0].Details.State != "empty" || report.Scopes[1].Details.State != "unavailable" || report.Scopes[1].Outcome != "canceled" {
		t.Fatalf("result=%#v calls=%d report=%#v", result, calls, report)
	}
	failure := errors.New("load failure")
	scope := Scope[struct{}, struct{}]{Name: "app", Operations: []Operation{Validate}, Acquire: func(context.Context, Request, struct{}, struct{}) (commandkit.Acquired[View], error) {
		return commandkit.Acquired[View]{}, failure
	}}
	app = newConfigTestApp(t, Command(Suite[struct{}, struct{}]{Scopes: []Scope[struct{}, struct{}]{scope}}))
	result = app.Execute(context.Background(), []string{"config", "validate", "--details"}, commandkit.Streams{Out: shortWriter{}, Err: io.Discard})
	if !errors.Is(result.Cause, failure) || result.Presentation.Output.State != commandkit.DeliveryIncomplete {
		t.Fatalf("failure and delivery: %#v", result)
	}
	out.Reset()
	result = app.Execute(context.Background(), []string{"config", "validate", "--details", "--quiet"}, commandkit.Streams{Out: &out, Err: io.Discard})
	if !errors.Is(result.Cause, failure) || out.Len() != 0 {
		t.Fatalf("quiet failure: %#v %q", result, out.String())
	}
}

func TestDetailedValidationReportsNativeLoadError(t *testing.T) {
	_, failure := configkit.Load[map[string]any](configkit.Bytes("invalid source", []byte("invalid: [")))
	var native *configkit.LoadError
	if !errors.As(failure, &native) {
		t.Fatalf("fixture: %v", failure)
	}
	scope := FromConfigKit("app", "", func(context.Context, Selection, struct{}, struct{}) (*configkit.Result[map[string]any], error) {
		return nil, failure
	})
	app := newConfigTestApp(t, Command(Suite[struct{}, struct{}]{Scopes: []Scope[struct{}, struct{}]{scope}}))
	var out bytes.Buffer
	result := app.Execute(context.Background(), []string{"config", "validate", "--details", "--format=json"}, commandkit.Streams{Out: &out, Err: io.Discard})
	var report validationReport
	if err := json.Unmarshal(out.Bytes(), &report); err != nil {
		t.Fatal(err)
	}
	if !errors.Is(result.Cause, failure) || len(report.Scopes) != 1 || report.Scopes[0].Outcome != "failed" || report.Scopes[0].Details.State != "present" || len(report.Scopes[0].Details.Findings) != len(native.Diagnostics()) {
		t.Fatalf("native failure: %#v %q", result, out.String())
	}
}