// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: MIT

package main

import (
	"bytes"
	"encoding/json"
	"errors"
	"strings"
	"testing"
	"time"

	"sourcedock.dev/petrbalvin/interpres"
)

func TestRunParsesValidTOML(t *testing.T) {
	var stdout, stderr bytes.Buffer
	in := bytes.NewReader([]byte(`name = "x"
port = 8080
enabled = true
`))
	if code := Run(in, &stdout, &stderr); code != 0 {
		t.Fatalf("Run returned %d, stderr = %q", code, stderr.String())
	}
	var got map[string]any
	if err := json.Unmarshal(stdout.Bytes(), &got); err != nil {
		t.Fatalf("invalid JSON output: %v\n%s", err, stdout.String())
	}
	if name := got["name"].(map[string]any); name["type"] != "string" || name["value"] != "x" {
		t.Errorf("name = %#v", got["name"])
	}
	if port := got["port"].(map[string]any); port["type"] != "integer" || port["value"] != "8080" {
		t.Errorf("port = %#v", got["port"])
	}
	if en := got["enabled"].(map[string]any); en["type"] != "bool" || en["value"] != "true" {
		t.Errorf("enabled = %#v", got["enabled"])
	}
}

func TestRunRejectsInvalidInput(t *testing.T) {
	var stdout, stderr bytes.Buffer
	in := bytes.NewReader([]byte("v = \n"))
	code := Run(in, &stdout, &stderr)
	if code != 1 {
		t.Errorf("Run returned %d, want 1 (parse error); stderr = %q", code, stderr.String())
	}
	if stdout.Len() != 0 {
		t.Errorf("stdout should be empty on parse error, got %q", stdout.String())
	}
}

func TestRunReadErrorReturnsTwo(t *testing.T) {
	var stdout, stderr bytes.Buffer
	code := Run(errorReader{}, &stdout, &stderr)
	if code != 2 {
		t.Errorf("Run returned %d, want 2 (read error); stderr = %q", code, stderr.String())
	}
	if !strings.Contains(stderr.String(), "read stdin") {
		t.Errorf("stderr = %q, want it to mention 'read stdin'", stderr.String())
	}
}

// errorReader is an io.Reader that always reports an error.
type errorReader struct{}

func (errorReader) Read(_ []byte) (int, error) { return 0, errors.New("boom") }

func TestRunEncodeErrorReturnsTwo(t *testing.T) {
	var stderr bytes.Buffer
	w := errorWriter{}
	in := bytes.NewReader([]byte(`k = "v"` + "\n"))
	code := Run(in, w, &stderr)
	if code != 2 {
		t.Errorf("Run returned %d, want 2 (encode error); stderr = %q", code, stderr.String())
	}
	if !strings.Contains(stderr.String(), "encode") {
		t.Errorf("stderr = %q, want it to mention 'encode'", stderr.String())
	}
}

// errorWriter is an io.Writer that always reports an error.
type errorWriter struct{}

func (errorWriter) Write(_ []byte) (int, error) { return 0, errors.New("boom") }

func TestTagHandlesAllScalarTypes(t *testing.T) {
	now := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
	ldt := interpres.LocalDateTime{Time: now}
	ld := interpres.LocalDate{Time: time.Date(2026, 1, 2, 0, 0, 0, 0, time.UTC)}
	lt := interpres.LocalTime{Time: time.Date(0, 1, 1, 3, 4, 5, 0, time.UTC)}

	cases := []struct {
		name string
		in   any
		want map[string]string
	}{
		{"string", "x", map[string]string{"type": "string", "value": "x"}},
		{"bool", true, map[string]string{"type": "bool", "value": "true"}},
		{"bool-false", false, map[string]string{"type": "bool", "value": "false"}},
		{"int64", int64(42), map[string]string{"type": "integer", "value": "42"}},
		{"float", 1.5, map[string]string{"type": "float", "value": "1.5"}},
		{"time", now, map[string]string{"type": "datetime", "value": "2026-01-02T03:04:05Z"}},
		{"ldt", ldt, map[string]string{"type": "datetime-local", "value": "2026-01-02T03:04:05"}},
		{"ld", ld, map[string]string{"type": "date-local", "value": "2026-01-02"}},
		{"lt", lt, map[string]string{"type": "time-local", "value": "03:04:05"}},
	}
	for _, c := range cases {
		got, err := tag(c.in)
		if err != nil {
			t.Errorf("%s: tag returned error %v", c.name, err)
			continue
		}
		m, ok := got.(map[string]string)
		if !ok {
			t.Errorf("%s: tag returned %T, want map[string]string", c.name, got)
			continue
		}
		if m["type"] != c.want["type"] || m["value"] != c.want["value"] {
			t.Errorf("%s: tag = %#v, want %#v", c.name, m, c.want)
		}
	}
}

func TestTagRejectsUnsupportedType(t *testing.T) {
	// Channels are not produced by the parser; tag must reject them explicitly.
	var ch chan int
	got, err := tag(ch)
	if err == nil {
		t.Fatalf("expected error for chan int, got value %#v", got)
	}
	if !strings.Contains(err.Error(), "unsupported") {
		t.Errorf("err = %v, want substring 'unsupported'", err)
	}
	if got != nil {
		t.Errorf("got = %#v, want nil", got)
	}

	// The same applies when an unsupported type is nested inside a table.
	got, err = tag(map[string]any{"x": ch})
	if err == nil {
		t.Fatalf("expected error for nested chan int, got %#v", got)
	}
}

// Exercise the table, array-of-tables, and array shapes so all of tag's
// switch arms are visited.
func TestTagHandlesContainers(t *testing.T) {
	tbl := map[string]any{
		"name": "x",
		"items": []any{
			int64(1), int64(2),
		},
	}
	got, err := tag(tbl)
	if err != nil {
		t.Fatalf("tag(tbl) returned error: %v", err)
	}
	m, ok := got.(map[string]any)
	if !ok {
		t.Fatalf("tag returned %T, want map", got)
	}
	name, ok := m["name"].(map[string]string)
	if !ok || name["value"] != "x" {
		t.Errorf("name = %#v", m["name"])
	}
	items, ok := m["items"].([]any)
	if !ok {
		t.Fatalf("items = %T, want []any", m["items"])
	}
	if len(items) != 2 {
		t.Fatalf("len(items) = %d, want 2", len(items))
	}
	for _, raw := range items {
		if _, ok := raw.(map[string]string); !ok {
			t.Errorf("item = %T, want map[string]string", raw)
		}
	}

	// Direct tests of the array branches.
	if got, err := tag([]any{int64(1)}); err != nil {
		t.Errorf("tag([]any) returned error: %v", err)
	} else if len(got.([]any)) != 1 {
		t.Errorf("[]any tag = %#v", got)
	}
	if got, err := tag([]map[string]any{{"k": "v"}}); err != nil {
		t.Errorf("tag([]map) returned error: %v", err)
	} else if len(got.([]any)) != 1 {
		t.Errorf("[]map[string]any tag = %#v", got)
	}
}

func TestFormatFloatAllBranches(t *testing.T) {
	cases := map[float64]string{
		1.5:     "1.5",
		0:       "0",
		1e10:    "1e+10",
		-2.5e-3: "-0.0025",
	}
	for in, want := range cases {
		if got := formatFloat(in); got != want {
			t.Errorf("formatFloat(%v) = %q, want %q", in, got, want)
		}
	}
}

func TestTaggedHelper(t *testing.T) {
	got := tagged("string", "x")
	if got["type"] != "string" || got["value"] != "x" {
		t.Errorf("tagged = %#v", got)
	}
}