package controllers

import (
	"errors"
	"net/http"
	"slices"
	"strconv"
	"strings"
	"time"

	"git.golem15.com/golem15/sm-user-plugin/classes"
	"git.golem15.com/golem15/sm-user-plugin/models"
	"git.golem15.com/golem15/summercms/modules/backpack"
	"git.golem15.com/golem15/summercms/modules/bouncer"
	"git.golem15.com/golem15/summercms/modules/wire"
	"gorm.io/gorm"
)

// APITokenStore mints one shared personal API token for the authenticated
// user. The clear-text token appears only in this response.
func APITokenStore(app *backpack.App) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		db, user, ok := apiTokenDeps(w, r, app)
		if !ok {
			return
		}
		fields, err := readFields(r)
		if err != nil {
			writeOpaque500(w)
			return
		}
		name := strings.TrimSpace(strField(fields, "name"))
		if name == "" || len(name) > 255 {
			writeValidation(w, map[string][]string{"name": {"The name field is required and may not be longer than 255 characters."}})
			return
		}
		scopes, err := apiTokenScopes(fields["scopes"])
		if err != nil {
			writeValidation(w, map[string][]string{"scopes": {err.Error()}})
			return
		}
		var expiresAt *time.Time
		if raw := strings.TrimSpace(strField(fields, "expires_at")); raw != "" {
			parsed, err := time.Parse(time.RFC3339, raw)
			if err != nil {
				writeValidation(w, map[string][]string{"expires_at": {"The expires_at field must be a valid RFC3339 date."}})
				return
			}
			expiresAt = &parsed
		}
		prefix, err := classes.APITokenPrefix(app)
		if err != nil {
			writeOpaque500(w)
			return
		}
		secret, token, err := classes.MintAPIToken(prefix, user.ID, name, scopes, expiresAt, nil)
		if err != nil || db.WithContext(r.Context()).Create(token).Error != nil {
			writeOpaque500(w)
			return
		}
		writeJSON(w, http.StatusCreated, map[string]any{"token": secret, "meta": apiTokenJSON(token)})
	}
}

// APITokenIndex lists the caller's live personal tokens without hashes.
func APITokenIndex(app *backpack.App) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		db, user, ok := apiTokenDeps(w, r, app)
		if !ok {
			return
		}
		var rows []models.APIToken
		if err := db.WithContext(r.Context()).
			Where("user_id = ? AND oauth_client_id IS NULL AND revoked_at IS NULL", user.ID).
			Order("created_at DESC").Find(&rows).Error; err != nil {
			writeOpaque500(w)
			return
		}
		data := make([]map[string]any, 0, len(rows))
		for i := range rows {
			data = append(data, apiTokenJSON(&rows[i]))
		}
		writeJSON(w, http.StatusOK, map[string]any{"data": wire.Slice(data)})
	}
}

// APITokenDestroy revokes one live personal token owned by the caller.
func APITokenDestroy(app *backpack.App) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		db, user, ok := apiTokenDeps(w, r, app)
		if !ok {
			return
		}
		id, err := strconv.ParseUint(r.PathValue("id"), 10, 64)
		if err != nil || id == 0 {
			writeJSON(w, http.StatusNotFound, map[string]any{"error": "Token not found"})
			return
		}
		var token models.APIToken
		err = db.WithContext(r.Context()).Where("user_id = ? AND oauth_client_id IS NULL", user.ID).First(&token, id).Error
		if errors.Is(err, gorm.ErrRecordNotFound) {
			writeJSON(w, http.StatusNotFound, map[string]any{"error": "Token not found"})
			return
		}
		if err != nil || classes.RevokeAPIToken(db.WithContext(r.Context()), &token) != nil {
			writeOpaque500(w)
			return
		}
		writeJSON(w, http.StatusOK, map[string]any{"data": map[string]any{"revoked": true}})
	}
}

func apiTokenDeps(w http.ResponseWriter, r *http.Request, app *backpack.App) (*gorm.DB, *bouncer.Principal, bool) {
	if app == nil {
		writeOpaque500(w)
		return nil, nil, false
	}
	db, ok := app.Lookup[*gorm.DB]()
	if !ok || db == nil {
		writeOpaque500(w)
		return nil, nil, false
	}
	user, ok := bouncer.User(r.Context())
	if !ok || user == nil || user.ID == 0 {
		writeUnauthorized(w)
		return nil, nil, false
	}
	return db, user, true
}

func apiTokenScopes(raw any) ([]string, error) {
	if raw == nil {
		return nil, nil
	}
	values, ok := raw.([]any)
	if !ok {
		return nil, errors.New("The scopes field must be an array.")
	}
	out := make([]string, 0, len(values))
	for _, rawScope := range values {
		scope, ok := rawScope.(string)
		if !ok || !slices.Contains(classes.AllowedAPITokenScopes, scope) {
			return nil, errors.New("The selected scope is invalid.")
		}
		out = append(out, scope)
	}
	return out, nil
}

func apiTokenJSON(token *models.APIToken) map[string]any {
	name := ""
	if token.Name != nil {
		name = *token.Name
	}
	return map[string]any{
		"id": token.ID, "name": name, "scopes": wire.Slice(token.Scopes.Get()),
		"last_used_at": token.LastUsedAt, "last_used_ip": token.LastUsedIP,
		"expires_at": token.ExpiresAt, "revoked_at": token.RevokedAt,
		"created_at": token.CreatedAt,
	}
}