package servicecontext

import (
	"context"
	"errors"
	"example.com/userService/internal/middleware"
	userrepo "example.com/userService/internal/repository/user"
	"example.com/userService/internal/settings"
	"git.yuntuo.hk/k2safe/go-omni/database"
	"git.yuntuo.hk/k2safe/go-omni/health"
	"git.yuntuo.hk/k2safe/go-omni/httpx"
	"git.yuntuo.hk/k2safe/go-omni/logx"
	"git.yuntuo.hk/k2safe/go-omni/storage"
	"github.com/go-sql-driver/mysql"
	"net/http"
	"sync"
	"time"
)

// Context owns infrastructure, while Logger is borrowed from main.
// Add business repositories here; HTTP contracts do not define database tables.
type Context struct {
	Users       userrepo.UnitOfWork
	Logger      *logx.Logger
	Health      *health.Checker
	Middlewares map[string]httpx.Middleware
	DB          *database.DB

	Files        storage.Store
	Uploads      *storage.Uploader
	Downloads    storage.Presigner
	UploadLinks  storage.UploadPresigner
	FileHTTP     http.Handler
	storageClose func() error

	closeMu   sync.Mutex
	closed    bool
	closeOnce sync.Once
	closeErr  error
}

// Pass the settings loaded by main. The optional form supports lightweight
// tests without infrastructure; selected adapters still require valid settings.
func New(ctx context.Context, logger *logx.Logger, configs ...settings.Config) (result *Context, err error) {
	if ctx == nil {
		ctx = context.Background()
	}
	if err = ctx.Err(); err != nil {
		return nil, err
	}
	if len(configs) > 1 {
		return nil, errors.New("expected at most one configuration")
	}
	cfg := settings.Default()
	if len(configs) == 1 {
		cfg = configs[0]
	}
	_ = cfg
	checker, err := health.New()
	if err != nil {
		return nil, err
	}
	c := &Context{Logger: logger, Health: checker, Middlewares: middleware.Defaults()}
	defer func() {
		if err != nil {
			err = errors.Join(err, c.Close())
		}
	}()

	if err = cfg.Validate(); err != nil {
		return nil, err
	}
	dsn, parseErr := mysql.ParseDSN(cfg.Database.DSN)
	if parseErr != nil || dsn.DBName == "" {
		return nil, errors.New("GO_OMNI_DB_DSN must contain a valid MySQL database name")
	}
	dsn.ParseTime = true
	dsn.Loc = time.UTC
	cfg.Database.DSN = dsn.FormatDSN()
	c.DB, err = database.Open(ctx, cfg.Database)
	if err != nil {
		return nil, err
	}
	if err = checker.Add(health.Probe{Name: "database", Timeout: cfg.Database.PingTimeout, Check: c.DB.Health}); err != nil {
		return nil, err
	}

	if err = c.InitStorage(ctx, cfg.Storage); err != nil {
		return nil, err
	}
	c.Users = userrepo.NewStore(c.DB)
	checkCtx, cancel := context.WithTimeout(ctx, cfg.Database.PingTimeout)
	defer cancel()
	if err = userrepo.NewStore(c.DB).CheckSchema(checkCtx); err != nil {
		return nil, errors.New("user schema is missing or incompatible; apply migrations first")
	}
	authHook, authErr := middleware.NewAuthFromEnv()
	if authErr != nil {
		return nil, authErr
	}
	c.Middlewares["Auth"] = authHook
	return c, nil
}

// Close is idempotent, including startup failure and graceful shutdown.
func (c *Context) Close() error {
	if c == nil {
		return nil
	}
	c.closeMu.Lock()
	defer c.closeMu.Unlock()
	c.closed = true
	c.closeOnce.Do(func() {
		if c.storageClose != nil {
			c.closeErr = errors.Join(c.closeErr, c.storageClose())
		}
		if c.DB != nil {
			c.closeErr = errors.Join(c.closeErr, c.DB.Close())
		}
	})
	return c.closeErr
}