package controller

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"time"

	"github.com/kandev/kandev/internal/agent/agents"
	"github.com/kandev/kandev/internal/agent/hostutility"
	"github.com/kandev/kandev/internal/agent/mcpconfig"
	"github.com/kandev/kandev/internal/agent/settings/cliflags"
	"github.com/kandev/kandev/internal/agent/settings/dto"
	"github.com/kandev/kandev/internal/agent/settings/models"
	"go.uber.org/zap"
)

type UpdateAgentProfileMcpConfigRequest struct {
	Enabled bool
	Servers map[string]mcpconfig.ServerDef
	Meta    map[string]any
}

func (c *Controller) GetAgentProfileMcpConfig(ctx context.Context, profileID string) (*dto.AgentProfileMcpConfigDTO, error) {
	config, err := c.mcpService.GetConfigByProfileID(ctx, profileID)
	if err != nil {
		if errors.Is(err, mcpconfig.ErrAgentProfileNotFound) {
			return nil, ErrAgentProfileNotFound
		}
		if errors.Is(err, mcpconfig.ErrAgentMcpUnsupported) {
			return nil, ErrAgentMcpUnsupported
		}
		return nil, err
	}
	return &dto.AgentProfileMcpConfigDTO{
		ProfileID: config.ProfileID,
		Enabled:   config.Enabled,
		Servers:   config.Servers,
		Meta:      config.Meta,
	}, nil
}

func (c *Controller) UpdateAgentProfileMcpConfig(ctx context.Context, profileID string, req UpdateAgentProfileMcpConfigRequest) (*dto.AgentProfileMcpConfigDTO, error) {
	config, err := c.mcpService.UpsertConfigByProfileID(ctx, profileID, &mcpconfig.ProfileConfig{
		Enabled: req.Enabled,
		Servers: req.Servers,
		Meta:    req.Meta,
	})
	if err != nil {
		if errors.Is(err, mcpconfig.ErrAgentProfileNotFound) {
			return nil, ErrAgentProfileNotFound
		}
		if errors.Is(err, mcpconfig.ErrAgentMcpUnsupported) {
			return nil, ErrAgentMcpUnsupported
		}
		return nil, err
	}
	return &dto.AgentProfileMcpConfigDTO{
		ProfileID: config.ProfileID,
		Enabled:   config.Enabled,
		Servers:   config.Servers,
		Meta:      config.Meta,
	}, nil
}

// EnsureDefaultMcpConfig ensures all agent profiles that support MCP have
// MCP enabled by default. The kandev MCP server is automatically injected
// by agentctl at session creation time, so profiles don't need to explicitly
// configure it.
func (c *Controller) EnsureDefaultMcpConfig(ctx context.Context) error {
	agentList, err := c.repo.ListAgents(ctx)
	if err != nil {
		return err
	}

	for _, agent := range agentList {
		if !agent.SupportsMCP {
			continue
		}

		profiles, err := c.repo.ListAgentProfiles(ctx, agent.ID)
		if err != nil {
			return err
		}

		for _, profile := range profiles {
			if err := c.ensureProfileMcpConfig(ctx, profile); err != nil {
				return err
			}
		}
	}

	return nil
}

func (c *Controller) ensureProfileMcpConfig(ctx context.Context, profile *models.AgentProfile) error {
	// Check if MCP config already exists
	existingConfig, err := c.repo.GetAgentProfileMcpConfig(ctx, profile.ID)
	if err != nil && !errors.Is(err, sql.ErrNoRows) {
		return err
	}

	// Skip if config already exists (don't overwrite user settings)
	if existingConfig != nil {
		return nil
	}

	// Create default MCP config with MCP enabled but no servers configured.
	// The kandev MCP server is automatically injected by agentctl when
	// creating a new session. Users can add additional external MCP servers.
	config := &models.AgentProfileMcpConfig{
		ProfileID: profile.ID,
		Enabled:   true,
		Servers:   map[string]interface{}{},
		Meta:      map[string]interface{}{},
		CreatedAt: time.Now().UTC(),
		UpdatedAt: time.Now().UTC(),
	}

	if err := c.repo.UpsertAgentProfileMcpConfig(ctx, config); err != nil {
		c.logger.Warn("failed to create default MCP config for profile",
			zap.String("profile_id", profile.ID),
			zap.String("profile_name", profile.Name),
			zap.Error(err))
		return nil
	}

	c.logger.Info("created default MCP config for profile",
		zap.String("profile_id", profile.ID),
		zap.String("profile_name", profile.Name))
	return nil
}

// GetAgentLogo returns the SVG logo bytes for the given agent and variant.
func (c *Controller) GetAgentLogo(ctx context.Context, agentName string, variant agents.LogoVariant) ([]byte, error) {
	ag, ok := c.agentRegistry.Get(agentName)
	if !ok {
		return nil, ErrAgentNotFound
	}
	data := ag.Logo(variant)
	if len(data) == 0 {
		return nil, ErrLogoNotAvailable
	}
	return data, nil
}

// resolvePermissionDefaults extracts the default permission values from agent settings.
func resolvePermissionDefaults(permSettings map[string]agents.PermissionSetting) (autoApprove, allowIndexing, skipPermissions bool) {
	if permSettings == nil {
		return
	}
	if s, exists := permSettings[agents.PermissionKeyAutoApprove]; exists {
		autoApprove = s.Default
	}
	if s, exists := permSettings["allow_indexing"]; exists {
		allowIndexing = s.Default
	}
	if s, exists := permSettings["dangerously_skip_permissions"]; exists {
		skipPermissions = s.Default
	}
	return
}

// CommandPreviewRequest contains the draft settings for command preview
type CommandPreviewRequest struct {
	Model              string
	PermissionSettings map[string]bool
	CLIPassthrough     bool
	CLIFlags           []dto.CLIFlagDTO
}

// PreviewAgentCommand generates a preview of the CLI command that will be executed
func (c *Controller) PreviewAgentCommand(ctx context.Context, agentName string, req CommandPreviewRequest) (*dto.CommandPreviewResponse, error) {
	agentConfig, ok := c.agentRegistry.Get(agentName)
	if !ok {
		return nil, fmt.Errorf("agent type %q not found in registry", agentName)
	}

	// Resolve the user-configured cli_flags list into argv tokens. The
	// launch path does the same via cliflags.Resolve; mirroring it here
	// keeps the preview faithful to what the agent subprocess will see.
	// Tolerate malformed entries silently — the preview is informational.
	cliFlagTokens, _ := cliflags.Resolve(cliFlagsFromDTO(req.CLIFlags))

	// Passthrough: BuildPassthroughCommand emits permission flags via Settings();
	// the launch path (manager_passthrough.go) does not append CLIFlagTokens for
	// passthrough, so the preview must match — otherwise permission flags that
	// the legacy allow_indexing backfill also pushes into CLIFlags get rendered
	// twice (e.g. Auggie's --allow-indexing).
	// ACP: mirror lifecycle.CommandBuilder.BuildCommand by appending CLIFlagTokens
	// after the agent's BuildCommand.
	var cmd agents.Command
	if ptAgent, ok := agentConfig.(agents.PassthroughAgent); ok && req.CLIPassthrough {
		cmd = ptAgent.BuildPassthroughCommand(agents.PassthroughOptions{
			Model:            req.Model,
			PermissionValues: req.PermissionSettings,
		})
	} else {
		cmd = agentConfig.BuildCommand(agents.CommandOptions{
			Model:            req.Model,
			PermissionValues: req.PermissionSettings,
			CLIFlagTokens:    cliFlagTokens,
		})
		if len(cliFlagTokens) > 0 {
			cmd = cmd.With().Flag(cliFlagTokens...).Build()
		}
	}

	return &dto.CommandPreviewResponse{
		Supported:     true,
		Command:       cmd.Args(),
		CommandString: buildCommandString(cmd.Args()),
	}, nil
}

// FetchDynamicModels returns models and modes for an agent from the host
// utility capability cache populated by the ACP probe at boot. The refresh
// flag triggers a live Refresh() call against the warm host instance.
func (c *Controller) FetchDynamicModels(ctx context.Context, agentName string, refresh bool) (*dto.DynamicModelsResponse, error) {
	if _, ok := c.agentRegistry.Get(agentName); !ok {
		return nil, fmt.Errorf("agent %q not found", agentName)
	}
	if c.hostUtility == nil {
		return &dto.DynamicModelsResponse{
			AgentName: agentName,
			Status:    "not_configured",
		}, nil
	}

	var caps hostutility.AgentCapabilities
	if refresh {
		var err error
		caps, err = c.hostUtility.Refresh(ctx, agentName)
		if err != nil {
			s := err.Error()
			return &dto.DynamicModelsResponse{
				AgentName: agentName,
				Status:    string(hostutility.StatusFailed),
				Error:     &s,
			}, nil
		}
	} else {
		var ok bool
		caps, ok = c.hostUtility.Get(agentName)
		if !ok {
			return &dto.DynamicModelsResponse{
				AgentName: agentName,
				Status:    "not_configured",
			}, nil
		}
	}

	resp := &dto.DynamicModelsResponse{
		AgentName:      agentName,
		Status:         string(caps.Status),
		CurrentModelID: caps.CurrentModelID,
		CurrentModeID:  caps.CurrentModeID,
		Models:         []dto.ModelEntryDTO{},
		Modes:          []dto.ModeEntryDTO{},
	}
	if caps.Error != "" {
		e := caps.Error
		resp.Error = &e
	}
	for _, m := range caps.Models {
		resp.Models = append(resp.Models, dto.ModelEntryDTO{
			ID:          m.ID,
			Name:        m.Name,
			Description: m.Description,
			IsDefault:   m.ID == caps.CurrentModelID,
			Meta:        m.Meta,
		})
	}
	for _, m := range caps.Modes {
		resp.Modes = append(resp.Modes, dto.ModeEntryDTO{
			ID:          m.ID,
			Name:        m.Name,
			Description: m.Description,
			Meta:        m.Meta,
		})
	}
	for _, c := range caps.Commands {
		resp.Commands = append(resp.Commands, dto.CommandEntryDTO{
			Name:        c.Name,
			Description: c.Description,
		})
	}
	return resp, nil
}