package handlers

import (
	"encoding/json"
	"net/http"

	"github.com/andyleap/hnh-map/internal/app"
	"github.com/andyleap/hnh-map/internal/app/services"
)

type loginRequest struct {
	User string `json:"user"`
	Pass string `json:"pass"`
}

type meResponse struct {
	Username string   `json:"username"`
	Auths    []string `json:"auths"`
	Tokens   []string `json:"tokens,omitempty"`
	Prefix   string   `json:"prefix,omitempty"`
	Email    string   `json:"email,omitempty"`
}

type passwordRequest struct {
	Pass string `json:"pass"`
}

type meUpdateRequest struct {
	Email string `json:"email"`
}

// APILogin handles POST /map/api/login.
func (h *Handlers) APILogin(rw http.ResponseWriter, req *http.Request) {
	if !h.requireMethod(rw, req, http.MethodPost) {
		return
	}
	ctx := req.Context()
	var body loginRequest
	if err := json.NewDecoder(req.Body).Decode(&body); err != nil {
		JSONError(rw, http.StatusBadRequest, "bad request", "BAD_REQUEST")
		return
	}
	if u := h.Auth.GetUserByUsername(ctx, body.User); u != nil && u.Pass == nil {
		JSONError(rw, http.StatusUnauthorized, "Use OAuth to sign in", "OAUTH_ONLY")
		return
	}
	u := h.Auth.GetUser(ctx, body.User, body.Pass)
	if u == nil {
		if boot := h.Auth.BootstrapAdmin(ctx, body.User, body.Pass, services.GetBootstrapPassword()); boot != nil {
			u = boot
		} else {
			JSONError(rw, http.StatusUnauthorized, "Unauthorized", "UNAUTHORIZED")
			return
		}
	}
	sessionID := h.Auth.CreateSession(ctx, body.User, u.Auths.Has("tempadmin"))
	if sessionID == "" {
		JSONError(rw, http.StatusInternalServerError, "internal error", "INTERNAL_ERROR")
		return
	}
	http.SetCookie(rw, &http.Cookie{
		Name:     "session",
		Value:    sessionID,
		Path:     "/",
		MaxAge:   app.SessionMaxAge,
		HttpOnly: true,
		Secure:   req.TLS != nil,
		SameSite: http.SameSiteLaxMode,
	})
	JSON(rw, http.StatusOK, meResponse{Username: body.User, Auths: u.Auths})
}

// APISetup handles GET /map/api/setup.
func (h *Handlers) APISetup(rw http.ResponseWriter, req *http.Request) {
	if !h.requireMethod(rw, req, http.MethodGet) {
		return
	}
	JSON(rw, http.StatusOK, struct {
		SetupRequired bool `json:"setupRequired"`
	}{SetupRequired: h.Auth.SetupRequired(req.Context())})
}

// APILogout handles POST /map/api/logout.
func (h *Handlers) APILogout(rw http.ResponseWriter, req *http.Request) {
	if !h.requireMethod(rw, req, http.MethodPost) {
		return
	}
	ctx := req.Context()
	s := h.Auth.GetSession(ctx, req)
	if s != nil {
		h.Auth.DeleteSession(ctx, s)
	}
	rw.WriteHeader(http.StatusOK)
}

// APIMe handles GET /map/api/me.
func (h *Handlers) APIMe(rw http.ResponseWriter, req *http.Request) {
	if !h.requireMethod(rw, req, http.MethodGet) {
		return
	}
	ctx := req.Context()
	s := h.requireSession(rw, req)
	if s == nil {
		return
	}
	out := meResponse{Username: s.Username, Auths: s.Auths}
	out.Tokens, out.Prefix = h.Auth.GetUserTokensAndPrefix(ctx, s.Username)
	if u := h.Auth.GetUserByUsername(ctx, s.Username); u != nil {
		out.Email = u.Email
	}
	JSON(rw, http.StatusOK, out)
}

// APIMeUpdate handles PATCH /map/api/me (update current user email).
func (h *Handlers) APIMeUpdate(rw http.ResponseWriter, req *http.Request) {
	if !h.requireMethod(rw, req, http.MethodPatch) {
		return
	}
	s := h.requireSession(rw, req)
	if s == nil {
		return
	}
	ctx := req.Context()
	var body meUpdateRequest
	if err := json.NewDecoder(req.Body).Decode(&body); err != nil {
		JSONError(rw, http.StatusBadRequest, "bad request", "BAD_REQUEST")
		return
	}
	if err := h.Auth.SetUserEmail(ctx, s.Username, body.Email); err != nil {
		JSONError(rw, http.StatusInternalServerError, "internal error", "INTERNAL_ERROR")
		return
	}
	rw.WriteHeader(http.StatusOK)
}

// APIMeTokens handles POST /map/api/me/tokens.
func (h *Handlers) APIMeTokens(rw http.ResponseWriter, req *http.Request) {
	if !h.requireMethod(rw, req, http.MethodPost) {
		return
	}
	s := h.requireSession(rw, req)
	if s == nil {
		return
	}
	ctx := req.Context()
	if !s.Auths.Has(app.AUTH_UPLOAD) {
		JSONError(rw, http.StatusForbidden, "Forbidden", "FORBIDDEN")
		return
	}
	tokens := h.Auth.GenerateTokenForUser(ctx, s.Username)
	if tokens == nil {
		JSONError(rw, http.StatusInternalServerError, "internal error", "INTERNAL_ERROR")
		return
	}
	JSON(rw, http.StatusOK, map[string][]string{"tokens": tokens})
}

// APIMePassword handles POST /map/api/me/password.
func (h *Handlers) APIMePassword(rw http.ResponseWriter, req *http.Request) {
	if !h.requireMethod(rw, req, http.MethodPost) {
		return
	}
	s := h.requireSession(rw, req)
	if s == nil {
		return
	}
	ctx := req.Context()
	var body passwordRequest
	if err := json.NewDecoder(req.Body).Decode(&body); err != nil {
		JSONError(rw, http.StatusBadRequest, "bad request", "BAD_REQUEST")
		return
	}
	if err := h.Auth.SetUserPassword(ctx, s.Username, body.Pass); err != nil {
		JSONError(rw, http.StatusBadRequest, "bad request", "BAD_REQUEST")
		return
	}
	rw.WriteHeader(http.StatusOK)
}

// APIOAuthProviders handles GET /map/api/oauth/providers.
func (h *Handlers) APIOAuthProviders(rw http.ResponseWriter, req *http.Request) {
	if !h.requireMethod(rw, req, http.MethodGet) {
		return
	}
	JSON(rw, http.StatusOK, services.OAuthProviders())
}

// APIOAuthLogin handles GET /map/api/oauth/:provider/login.
func (h *Handlers) APIOAuthLogin(rw http.ResponseWriter, req *http.Request, provider string) {
	if !h.requireMethod(rw, req, http.MethodGet) {
		return
	}
	redirect := req.URL.Query().Get("redirect")
	authURL, err := h.Auth.OAuthInitLogin(req.Context(), provider, redirect, req)
	if err != nil {
		HandleServiceError(rw, err)
		return
	}
	http.Redirect(rw, req, authURL, http.StatusFound)
}

// APIOAuthCallback handles GET /map/api/oauth/:provider/callback.
func (h *Handlers) APIOAuthCallback(rw http.ResponseWriter, req *http.Request, provider string) {
	if !h.requireMethod(rw, req, http.MethodGet) {
		return
	}
	code := req.URL.Query().Get("code")
	state := req.URL.Query().Get("state")
	if code == "" || state == "" {
		JSONError(rw, http.StatusBadRequest, "missing code or state", "BAD_REQUEST")
		return
	}
	sessionID, redirectTo, err := h.Auth.OAuthHandleCallback(req.Context(), provider, code, state, req)
	if err != nil {
		HandleServiceError(rw, err)
		return
	}
	http.SetCookie(rw, &http.Cookie{
		Name:     "session",
		Value:    sessionID,
		Path:     "/",
		MaxAge:   app.SessionMaxAge,
		HttpOnly: true,
		Secure:   req.TLS != nil,
		SameSite: http.SameSiteLaxMode,
	})
	http.Redirect(rw, req, redirectTo, http.StatusFound)
}

// RedirectLogout handles GET /logout.
func (h *Handlers) RedirectLogout(rw http.ResponseWriter, req *http.Request) {
	if req.URL.Path != "/logout" {
		http.NotFound(rw, req)
		return
	}
	ctx := req.Context()
	s := h.Auth.GetSession(ctx, req)
	if s != nil {
		h.Auth.DeleteSession(ctx, s)
	}
	http.Redirect(rw, req, "/login", http.StatusFound)
}