package main

import (
	"bytes"
	"encoding/json"
	"os"
	"strings"
	"testing"

	"mxl-pattern-generator/internal/flowdef"
)

func TestParseArgsHelpStopsBeforeValidation(t *testing.T) {
	var stdout, stderr bytes.Buffer

	result, err := parseArgs([]string{"--help"}, &stdout, &stderr)
	if err != nil {
		t.Fatalf("parseArgs: %v", err)
	}
	if result.shouldRun {
		t.Fatal("shouldRun = true, want false")
	}
	if !result.args.showHelp {
		t.Fatal("showHelp = false, want true")
	}
	if !strings.Contains(stdout.String(), "Usage: mxl-gen") {
		t.Fatalf("help output does not contain usage: %q", stdout.String())
	}
	if stderr.Len() != 0 {
		t.Fatalf("stderr = %q, want empty", stderr.String())
	}
}

func TestParseArgsListPatternsStopsBeforeValidation(t *testing.T) {
	var stdout, stderr bytes.Buffer

	result, err := parseArgs([]string{"--list-patterns"}, &stdout, &stderr)
	if err != nil {
		t.Fatalf("parseArgs: %v", err)
	}
	if result.shouldRun {
		t.Fatal("shouldRun = true, want false")
	}
	if !result.args.listPatterns {
		t.Fatal("listPatterns = false, want true")
	}
	if !strings.Contains(stdout.String(), "ebu75") {
		t.Fatalf("pattern output does not contain ebu75: %q", stdout.String())
	}
	if stderr.Len() != 0 {
		t.Fatalf("stderr = %q, want empty", stderr.String())
	}
}

func TestParseArgsRejectsUnexpectedPositionalArguments(t *testing.T) {
	var stdout, stderr bytes.Buffer

	result, err := parseArgs([]string{"unexpected"}, &stdout, &stderr)
	if err == nil {
		t.Fatal("parseArgs returned nil error")
	}
	if result.shouldRun {
		t.Fatal("shouldRun = true, want false")
	}
	if !strings.Contains(err.Error(), "unexpected positional arguments") {
		t.Fatalf("error = %q", err)
	}
}

func TestParseArgsRejectsUnknownFlag(t *testing.T) {
	var stdout, stderr bytes.Buffer

	result, err := parseArgs([]string{"--not-a-flag"}, &stdout, &stderr)
	if err == nil {
		t.Fatal("parseArgs returned nil error")
	}
	if result.shouldRun {
		t.Fatal("shouldRun = true, want false")
	}
}

func TestValidateAudioArgsSkipsDisabledAudio(t *testing.T) {
	args := appArgs{
		audioChannels:     0,
		audioSamplingFreq: "unsupported",
		audioUUID:         "not-a-uuid",
	}

	if err := validateAudioArgs(&args); err != nil {
		t.Fatalf("validateAudioArgs: %v", err)
	}
	if args.audioUUID != "not-a-uuid" {
		t.Fatalf("audio UUID changed while audio is disabled: %q", args.audioUUID)
	}
}

func TestListPatternsIsSorted(t *testing.T) {
	var output bytes.Buffer
	listPatterns(&output)

	text := output.String()
	if strings.Index(text, "ebu100") > strings.Index(text, "ebu75") {
		t.Fatalf("patterns are not sorted: %q", text)
	}
}

func TestBuildVideoConfigFromArgs(t *testing.T) {
	args := appArgs{
		videoUUID:   "5fbec3b1-1b0f-417d-9059-8b94a47197ed",
		videoWidth:  1920,
		videoHeight: 1080,
		videoFPS:    "29.97",
		pattern:     "ebu75",
	}

	cfg, err := buildVideoConfig(args)
	if err != nil {
		t.Fatalf("buildVideoConfig: %v", err)
	}
	if cfg.Width() != 1920 || cfg.Height() != 1080 {
		t.Fatalf("dimensions = %dx%d, want 1920x1080", cfg.Width(), cfg.Height())
	}
	if cfg.Rate().Num != 30000 || cfg.Rate().Den != 1001 {
		t.Fatalf("rate = %d/%d, want 30000/1001", cfg.Rate().Num, cfg.Rate().Den)
	}
}

func TestBuildVideoConfigFromFile(t *testing.T) {
	definition, err := flowdef.NewV210Video(
		"5fbec3b1-1b0f-417d-9059-8b94a47197ed",
		3840,
		2160,
		flowdef.Rational{Numerator: 60000, Denominator: 1001},
	)
	if err != nil {
		t.Fatalf("NewV210Video: %v", err)
	}
	data, err := json.Marshal(definition)
	if err != nil {
		t.Fatalf("json.Marshal: %v", err)
	}
	path := t.TempDir() + "/video.json"
	if err := os.WriteFile(path, data, 0o600); err != nil {
		t.Fatalf("os.WriteFile: %v", err)
	}

	cfg, err := buildVideoConfig(appArgs{
		videoFlowDefFile: path,
		pattern:          "smpte",
		// These values must be ignored when a definition file is supplied.
		videoWidth:  1920,
		videoHeight: 1080,
		videoFPS:    "25",
	})
	if err != nil {
		t.Fatalf("buildVideoConfig: %v", err)
	}
	if cfg.Width() != 3840 || cfg.Height() != 2160 {
		t.Fatalf("dimensions = %dx%d, want file values 3840x2160", cfg.Width(), cfg.Height())
	}
	if cfg.Rate().Num != 60000 || cfg.Rate().Den != 1001 {
		t.Fatalf("rate = %d/%d, want file value 60000/1001", cfg.Rate().Num, cfg.Rate().Den)
	}
}