package task

import (
	"context"
	"fmt"
	"time"

	"gpt-plus/pkg/auth"
	"gpt-plus/pkg/chatgpt"
)

const (
	finalMembershipPolls     = 5
	finalMembershipPollDelay = 2 * time.Second
)

type finalMembershipState struct {
	Personal  *chatgpt.AccountInfo
	Workspace *chatgpt.AccountInfo
}

func (s *finalMembershipState) plusActive() bool {
	return plusMembershipActive(s.Personal)
}

func (s *finalMembershipState) teamActive() bool {
	return teamMembershipActive(s.Workspace)
}

func (s *finalMembershipState) satisfied(taskType string) bool {
	switch taskType {
	case TaskTypePlus:
		return s.plusActive()
	case TaskTypeTeam:
		return s.teamActive()
	case TaskTypeBoth:
		return s.plusActive() && s.teamActive()
	default:
		return false
	}
}

func (s *finalMembershipState) resultPlanForTask(taskType string) string {
	if s != nil && s.satisfied(taskType) {
		return taskType
	}
	return s.actualPlan()
}

func (s *finalMembershipState) actualPlan() string {
	switch {
	case s == nil:
		return "unknown"
	case s.plusActive() && s.teamActive():
		return TaskTypeBoth
	case s.teamActive():
		return "team"
	case s.plusActive():
		return "plus"
	case s.Personal != nil && s.Personal.PlanType != "":
		return s.Personal.PlanType
	case s.Workspace != nil && s.Workspace.PlanType != "":
		return s.Workspace.PlanType
	default:
		return "unknown"
	}
}

func (s *finalMembershipState) describe() string {
	return fmt.Sprintf("personal=%s workspace=%s", describeMembership(s.Personal), describeMembership(s.Workspace))
}

func plusMembershipActive(info *chatgpt.AccountInfo) bool {
	return info != nil &&
		info.Structure == "personal" &&
		info.PlanType == "plus" &&
		info.HasActiveSubscription &&
		info.SubscriptionID != ""
}

func teamMembershipActive(info *chatgpt.AccountInfo) bool {
	return info != nil &&
		info.Structure == "workspace" &&
		info.PlanType == "team"
}

func describeMembership(info *chatgpt.AccountInfo) string {
	if info == nil {
		return "none"
	}
	return fmt.Sprintf("%s/%s(active=%v sub=%t id=%s)",
		info.Structure, info.PlanType, info.HasActiveSubscription, info.SubscriptionID != "", info.AccountID)
}

func selectPersonalMembership(accounts []*chatgpt.AccountInfo) *chatgpt.AccountInfo {
	for _, acct := range accounts {
		if acct.Structure == "personal" {
			return acct
		}
	}
	return nil
}

func selectWorkspaceMembership(accounts []*chatgpt.AccountInfo, preferredID string) *chatgpt.AccountInfo {
	if preferredID != "" {
		for _, acct := range accounts {
			if acct.Structure == "workspace" && acct.AccountID == preferredID {
				return acct
			}
		}
	}
	for _, acct := range accounts {
		if acct.Structure == "workspace" && acct.PlanType == "team" {
			return acct
		}
	}
	for _, acct := range accounts {
		if acct.Structure == "workspace" {
			return acct
		}
	}
	return nil
}

func (r *TaskRunner) verifyTaskMembership(
	ctx context.Context,
	taskType string,
	session *chatgpt.Session,
	teamAccountID string,
	statusFn chatgpt.StatusFunc,
) (*finalMembershipState, error) {
	var lastState *finalMembershipState
	var lastErr error

	for attempt := 1; attempt <= finalMembershipPolls; attempt++ {
		if err := refreshVerificationTokens(ctx, session); err != nil && statusFn != nil {
			statusFn("  -> Final token refresh %d/%d failed: %v", attempt, finalMembershipPolls, err)
		}

		accounts, err := chatgpt.CheckAccountFull(session.Client, session.AccessToken, session.DeviceID)
		if err != nil {
			lastErr = fmt.Errorf("accounts/check failed: %w", err)
		} else {
			lastState = &finalMembershipState{
				Personal:  selectPersonalMembership(accounts),
				Workspace: selectWorkspaceMembership(accounts, teamAccountID),
			}
		}

		if (taskType == TaskTypeTeam || taskType == TaskTypeBoth) &&
			(lastState == nil || !lastState.teamActive()) &&
			teamAccountID != "" {
			workspaceToken, wsErr := chatgpt.GetWorkspaceAccessToken(session.Client, teamAccountID)
			if wsErr == nil {
				if wsAccounts, wsCheckErr := chatgpt.CheckAccountFull(session.Client, workspaceToken, session.DeviceID); wsCheckErr == nil {
					if lastState == nil {
						lastState = &finalMembershipState{}
					}
					lastState.Workspace = selectWorkspaceMembership(wsAccounts, teamAccountID)
				} else if lastErr == nil {
					lastErr = fmt.Errorf("workspace accounts/check failed: %w", wsCheckErr)
				}
			} else if lastErr == nil {
				lastErr = fmt.Errorf("workspace token refresh failed: %w", wsErr)
			}
		}

		if lastState != nil && statusFn != nil {
			statusFn("  -> Final membership %d/%d: %s", attempt, finalMembershipPolls, lastState.describe())
		}
		if lastState != nil && lastState.satisfied(taskType) {
			return lastState, nil
		}
		if lastState != nil {
			lastErr = fmt.Errorf("membership mismatch for %s: %s", taskType, lastState.describe())
		}

		if attempt < finalMembershipPolls {
			if err := sleepWithContext(ctx, finalMembershipPollDelay); err != nil {
				return lastState, err
			}
		}
	}

	if lastState != nil {
		return lastState, fmt.Errorf("final membership mismatch for %s: %s", taskType, lastState.describe())
	}
	if lastErr != nil {
		return nil, fmt.Errorf("final membership check failed for %s: %w", taskType, lastErr)
	}
	return nil, fmt.Errorf("final membership check failed for %s", taskType)
}

func refreshVerificationTokens(ctx context.Context, session *chatgpt.Session) error {
	if err := session.RefreshSession(); err == nil {
		return nil
	} else {
		tokens, tokenErr := auth.ObtainCodexTokens(ctx, session.Client, session.DeviceID, "")
		if tokenErr != nil {
			return fmt.Errorf("session refresh failed: %v; codex refresh failed: %w", err, tokenErr)
		}
		if tokens.AccessToken == "" {
			return fmt.Errorf("codex refresh returned empty access token")
		}
		session.AccessToken = tokens.AccessToken
		if tokens.RefreshToken != "" {
			session.RefreshToken = tokens.RefreshToken
		}
		if tokens.IDToken != "" {
			session.IDToken = tokens.IDToken
		}
		if tokens.ChatGPTAccountID != "" {
			session.AccountID = tokens.ChatGPTAccountID
		}
		return nil
	}
}

func sleepWithContext(ctx context.Context, delay time.Duration) error {
	timer := time.NewTimer(delay)
	defer timer.Stop()

	select {
	case <-ctx.Done():
		return ctx.Err()
	case <-timer.C:
		return nil
	}
}