package httpapi

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

	"github.com/vasyansk/imap-copier/internal/crypto"
	"github.com/vasyansk/imap-copier/internal/imapx"
	"github.com/vasyansk/imap-copier/internal/store"
)

type AccountView struct {
	ID            int64  `json:"id"`
	SrcLogin      string `json:"src_login"`
	DstLogin      string `json:"dst_login"`
	TestSrcStatus string `json:"test_src_status"`
	TestDstStatus string `json:"test_dst_status"`
	Status        string `json:"status"`
	Copied        int64  `json:"copied"`
	Skipped       int64  `json:"skipped"`
	Errors        int64  `json:"errors"`
	LastError     string `json:"last_error,omitempty"`
}

func accountDTO(a store.Account) AccountView {
	return AccountView{
		ID: a.ID, SrcLogin: a.SrcLogin, DstLogin: a.DstLogin,
		TestSrcStatus: a.TestSrcStatus, TestDstStatus: a.TestDstStatus,
		Status: a.Status, Copied: a.Copied, Skipped: a.Skipped, Errors: a.Errors,
		LastError: a.LastError,
	}
}

// handleProbeFolders tests both logins with the given credentials and returns
// the folder list on each side, so the UI can offer a source->destination
// folder mapping before the account is created. Credentials are not stored.
func (s *Server) handleProbeFolders(w http.ResponseWriter, r *http.Request) {
	taskID, err := pathID(r, "id")
	if err != nil {
		http.Error(w, "bad id", http.StatusBadRequest)
		return
	}
	task, err := s.store.GetTask(r.Context(), taskID)
	if err != nil {
		http.Error(w, "not found", http.StatusNotFound)
		return
	}
	srcEP, err := s.store.GetEndpoint(r.Context(), task.SrcEndpointID)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	dstEP, err := s.store.GetEndpoint(r.Context(), task.DstEndpointID)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	var body struct {
		SrcLogin string `json:"src_login"`
		SrcPass  string `json:"src_pass"`
		DstLogin string `json:"dst_login"`
		DstPass  string `json:"dst_pass"`
	}
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
		http.Error(w, "bad json", http.StatusBadRequest)
		return
	}
	probe := func(ep store.Endpoint, login, pass string) map[string]any {
		folders, err := imapx.TestLogin(r.Context(),
			imapx.Endpoint{Host: ep.Host, Port: ep.Port, TLSMode: ep.TLSMode},
			strings.TrimSpace(login), strings.TrimSpace(pass))
		if err != nil {
			return map[string]any{"ok": false, "error": err.Error(), "folders": []string{}}
		}
		return map[string]any{"ok": true, "folders": folders}
	}
	writeJSON(w, http.StatusOK, map[string]any{
		"src": probe(srcEP, body.SrcLogin, body.SrcPass),
		"dst": probe(dstEP, body.DstLogin, body.DstPass),
	})
}

// handleSetFolderMapping replaces the task's src->dst folder mapping.
func (s *Server) handleSetFolderMapping(w http.ResponseWriter, r *http.Request) {
	taskID, err := pathID(r, "id")
	if err != nil {
		http.Error(w, "bad id", http.StatusBadRequest)
		return
	}
	var body struct {
		Mapping map[string]string `json:"mapping"`
	}
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
		http.Error(w, "bad json", http.StatusBadRequest)
		return
	}
	if err := s.store.SetTaskFolderMapping(r.Context(), taskID, body.Mapping); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func pathID(r *http.Request, name string) (int64, error) {
	return strconv.ParseInt(r.PathValue(name), 10, 64)
}

func (s *Server) handleCreateAccount(w http.ResponseWriter, r *http.Request) {
	taskID, err := pathID(r, "id")
	if err != nil {
		http.Error(w, "bad id", http.StatusBadRequest)
		return
	}
	var body struct {
		SrcLogin string `json:"src_login"`
		SrcPass  string `json:"src_pass"`
		DstLogin string `json:"dst_login"`
		DstPass  string `json:"dst_pass"`
	}
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
		http.Error(w, "bad json", http.StatusBadRequest)
		return
	}
	// Trim surrounding whitespace — pasted app passwords / logins often carry a
	// stray trailing space or newline that the IMAP server rejects.
	body.SrcLogin = strings.TrimSpace(body.SrcLogin)
	body.SrcPass = strings.TrimSpace(body.SrcPass)
	body.DstLogin = strings.TrimSpace(body.DstLogin)
	body.DstPass = strings.TrimSpace(body.DstPass)
	srcEnc, err := crypto.Encrypt(s.cfg.EncKey, []byte(body.SrcPass))
	if err != nil {
		http.Error(w, "encrypt", http.StatusInternalServerError)
		return
	}
	dstEnc, err := crypto.Encrypt(s.cfg.EncKey, []byte(body.DstPass))
	if err != nil {
		http.Error(w, "encrypt", http.StatusInternalServerError)
		return
	}
	id, err := s.store.CreateAccount(r.Context(), store.Account{
		TaskID: taskID, SrcLogin: body.SrcLogin, SrcPassEnc: srcEnc,
		DstLogin: body.DstLogin, DstPassEnc: dstEnc,
	})
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	writeJSON(w, http.StatusCreated, map[string]int64{"id": id})
}