package mysql

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	"git.warky.dev/wdevs/relspecgo/pkg/models"
	"git.warky.dev/wdevs/relspecgo/pkg/writers"
)

func shopDB() *models.Database {
	s := models.InitSchema("shop")
	t := models.InitTable("users", "shop")
	add := func(name, typ string, mod func(*models.Column)) {
		c := models.InitColumn(name, "users", "shop")
		c.Type = typ
		if mod != nil {
			mod(c)
		}
		t.Columns[name] = c
	}
	add("id", "int", func(c *models.Column) { c.IsPrimaryKey, c.NotNull, c.AutoIncrement = true, true, true })
	add("email", "string", func(c *models.Column) { c.Length, c.NotNull = 255, true })
	add("nick", "string", nil)
	add("age", "int", func(c *models.Column) { c.Default = 18 })
	add("active", "boolean", func(c *models.Column) { c.Default = true })
	add("zeta", "string", nil)
	add("alpha", "string", nil)
	for _, name := range []string{"uq_b", "uq_a", "uq_c"} {
		u := models.InitConstraint(name, models.UniqueConstraint)
		u.Columns = []string{"email"}
		t.Constraints[name] = u
	}
	s.Tables = append(s.Tables, t)
	db := models.InitDatabase("shop")
	db.Schemas = append(db.Schemas, s)
	return db
}

func writeFile(t *testing.T, db *models.Database) string {
	t.Helper()
	out := filepath.Join(t.TempDir(), "out.sql")
	if err := NewWriter(&writers.WriterOptions{OutputPath: out}).WriteDatabase(db); err != nil {
		t.Fatal(err)
	}
	b, err := os.ReadFile(out)
	if err != nil {
		t.Fatal(err)
	}
	return string(b)
}

func TestWriteDatabase_ToFile(t *testing.T) {
	got := writeFile(t, shopDB())
	for _, want := range []string{
		"-- Database: shop", "CREATE TABLE IF NOT EXISTS `shop`.`users`",
		"`id` ", "AUTO_INCREMENT", "`email` VARCHAR(255) NOT NULL", "DEFAULT 18",
		"PRIMARY KEY (`id`)", "CONSTRAINT `uq_a` UNIQUE (`email`)", "ENGINE=InnoDB",
	} {
		if !strings.Contains(got, want) {
			t.Errorf("missing %q\n%s", want, got)
		}
	}
}

func TestWriteDatabase_Deterministic(t *testing.T) {
	first := writeFile(t, shopDB())
	for i := 0; i < 30; i++ {
		if got := writeFile(t, shopDB()); got != first {
			t.Fatalf("output differs on run %d:\n--- first\n%s\n--- got\n%s", i, first, got)
		}
	}
}

func TestWriteDatabase_UniqueConstraintsSorted(t *testing.T) {
	got := writeFile(t, shopDB())
	a, b, c := strings.Index(got, "`uq_a`"), strings.Index(got, "`uq_b`"), strings.Index(got, "`uq_c`")
	if !(a < b && b < c) {
		t.Errorf("unique constraints must be sorted by name: %d %d %d", a, b, c)
	}
}

func TestWriteSchemaAndTable_UseOutputPath(t *testing.T) {
	db := shopDB()
	dir := t.TempDir()

	sOut := filepath.Join(dir, "s.sql")
	if err := NewWriter(&writers.WriterOptions{OutputPath: sOut}).WriteSchema(db.Schemas[0]); err != nil {
		t.Fatal(err)
	}
	if b, _ := os.ReadFile(sOut); !strings.Contains(string(b), "CREATE TABLE IF NOT EXISTS `shop`.`users`") {
		t.Errorf("schema output:\n%s", b)
	}

	tOut := filepath.Join(dir, "t.sql")
	if err := NewWriter(&writers.WriterOptions{OutputPath: tOut}).WriteTable(db.Schemas[0].Tables[0]); err != nil {
		t.Fatal(err)
	}
	if b, _ := os.ReadFile(tOut); !strings.Contains(string(b), "CREATE TABLE IF NOT EXISTS `users`") {
		t.Errorf("table output (unqualified name):\n%s", b)
	}
}

func TestWriteSchema_WithoutWriterDoesNotPanic(t *testing.T) {
	defer func() {
		if r := recover(); r != nil {
			t.Fatalf("panic: %v", r)
		}
	}()
	s := shopDB().Schemas[0]
	s.Tables = nil // nothing to print to stdout
	if err := NewWriter(&writers.WriterOptions{}).WriteSchema(s); err != nil {
		t.Fatal(err)
	}
}

func TestWriteDatabase_Errors(t *testing.T) {
	if err := NewWriter(nil).WriteDatabase(shopDB()); err == nil || !strings.Contains(err.Error(), "options are required") {
		t.Errorf("nil options: %v", err)
	}
	bad := filepath.Join(t.TempDir(), "missing", "x.sql")
	if err := NewWriter(&writers.WriterOptions{OutputPath: bad}).WriteDatabase(shopDB()); err == nil {
		t.Error("bad output path must fail")
	}
}

func TestWriteDatabase_ConnectionFailure(t *testing.T) {
	opts := &writers.WriterOptions{Metadata: map[string]any{
		"connection_string": "u:p@tcp(127.0.0.1:1)/none?timeout=1s",
	}}
	if err := NewWriter(opts).WriteDatabase(shopDB()); err == nil || !strings.Contains(err.Error(), "failed to execute SQL") {
		t.Errorf("got %v", err)
	}
}

func TestQuoteHelpers(t *testing.T) {
	if got := quote("a`b"); got != "`a``b`" {
		t.Errorf("quote: %q", got)
	}
	if got := quoted([]string{"a", "b"}); got != "`a`, `b`" {
		t.Errorf("quoted: %q", got)
	}
	if got := quoted(nil); got != "" {
		t.Errorf("quoted(nil): %q", got)
	}
}

func TestPrimaryKeyConstraintOverridesColumnFlags(t *testing.T) {
	db := shopDB()
	tbl := db.Schemas[0].Tables[0]
	pk := models.InitConstraint("pk", models.PrimaryKeyConstraint)
	pk.Columns = []string{"email", "id"}
	tbl.Constraints["pk"] = pk
	if got := writeFile(t, db); !strings.Contains(got, "PRIMARY KEY (`email`, `id`)") {
		t.Errorf("composite pk:\n%s", got)
	}
}