package scanner

import (
	"context"
	"encoding/json"

	"s1d3sw1ped/robinhood-agentic-mcp/client"
	"s1d3sw1ped/robinhood-agentic-mcp/internal/wire"
)

const (
	toolFilterSpecs   = "get_scanner_filter_specs"
	toolDatapoints    = "get_scanner_datapoints"
	toolScans         = "get_scans"
	toolCreate        = "create_scan"
	toolPreview       = "preview_scan"
	toolRun           = "run_scan"
	toolUpdateFilters = "update_scan_filters"
	toolUpdateConfig  = "update_scan_config"
)

// Filter is one scanner filter (enum-based or expression-based).
type Filter struct {
	FilterType   string
	Predicate    string
	Values       []string
	Interval     string
	Length       int
	Plot         string
	Expression   string
	DisplayTitle string
}

// Column is one extra result column on a scan.
type Column struct {
	DisplayName string
	Expression  string
	Visible     *bool
	Order       *int
}

// FilterSpecsRequest is the argument set for get_scanner_filter_specs (none).
type FilterSpecsRequest struct{}

// FilterSpec is one filter type from get_scanner_filter_specs.
type FilterSpec struct {
	FilterType string `json:"filter_type"`
	Name       string `json:"name"`
}

// FilterSpecsResult is the parsed get_scanner_filter_specs payload.
type FilterSpecsResult struct {
	Specs []FilterSpec
}

// DatapointsRequest is the argument set for get_scanner_datapoints (none).
type DatapointsRequest struct{}

// Datapoint is one expression token from get_scanner_datapoints.
type Datapoint struct {
	Name string `json:"name"`
}

// DatapointsResult is the parsed get_scanner_datapoints payload.
type DatapointsResult struct {
	Datapoints []Datapoint
}

// ScansRequest is the argument set for get_scans (none).
type ScansRequest struct{}

// Scan is one saved scanner from get_scans.
type Scan struct {
	ID    string `json:"id"`
	Title string `json:"title"`
}

// ScansResult is the parsed get_scans payload.
type ScansResult struct {
	Scans []Scan `json:"scans"`
}

// CreateRequest is the argument set for create_scan.
type CreateRequest struct {
	ScanID  string
	Preset  string
	Filters []Filter
	Columns []Column
	Title   string
}

// ScanResult is a saved scan plus optional live rows.
type ScanResult struct {
	ID    string
	Title string
	Rows  []ScanRow
	Total int
}

// ScanRow is one live scanner match.
type ScanRow struct {
	Symbol       string
	InstrumentID string
}

// CreateResult is the parsed create_scan payload.
type CreateResult struct {
	ScanResult
}

// PreviewRequest is the argument set for preview_scan.
type PreviewRequest struct {
	Filters []Filter
	Columns []Column
}

// PreviewResult is the parsed preview_scan payload.
type PreviewResult struct {
	ScanResult
}

// RunRequest is the argument set for run_scan.
type RunRequest struct {
	ScanID string
}

// RunResult is the parsed run_scan payload.
type RunResult struct {
	ScanResult
}

// UpdateFiltersRequest is the argument set for update_scan_filters.
type UpdateFiltersRequest struct {
	ScanID  string
	Filters []Filter
}

// UpdateFiltersResult is the parsed update_scan_filters payload.
type UpdateFiltersResult struct {
	ScanResult
}

// UpdateConfigRequest is the argument set for update_scan_config.
type UpdateConfigRequest struct {
	ScanID           string
	SortingColumn    string
	SortingDirection string
	Columns          []Column
}

// UpdateConfigResult is the parsed update_scan_config payload.
type UpdateConfigResult struct {
	ScanResult
}

// FilterSpecs calls get_scanner_filter_specs.
func (c *Client) FilterSpecs(ctx context.Context, req FilterSpecsRequest) (FilterSpecsResult, error) {
	var out FilterSpecsResult
	if err := c.parse(ctx, toolFilterSpecs, map[string]any{}, &out); err != nil {
		return FilterSpecsResult{}, err
	}
	return out, nil
}

// Datapoints calls get_scanner_datapoints.
func (c *Client) Datapoints(ctx context.Context, req DatapointsRequest) (DatapointsResult, error) {
	var out DatapointsResult
	if err := c.parse(ctx, toolDatapoints, map[string]any{}, &out); err != nil {
		return DatapointsResult{}, err
	}
	return out, nil
}

// Scans calls get_scans.
func (c *Client) Scans(ctx context.Context, req ScansRequest) (ScansResult, error) {
	var out ScansResult
	if err := c.parse(ctx, toolScans, map[string]any{}, &out); err != nil {
		return ScansResult{}, err
	}
	return out, nil
}

// Create calls create_scan.
func (c *Client) Create(ctx context.Context, req CreateRequest) (CreateResult, error) {
	args := map[string]any{}
	if req.ScanID != "" {
		args["scan_id"] = req.ScanID
	}
	if req.Preset != "" {
		args["preset"] = req.Preset
	}
	if len(req.Filters) > 0 {
		args["filters"] = encodeFilters(req.Filters)
	}
	if len(req.Columns) > 0 {
		args["columns"] = encodeColumns(req.Columns)
	}
	if req.Title != "" {
		args["title"] = req.Title
	}
	var out CreateResult
	if err := c.parse(ctx, toolCreate, args, &out); err != nil {
		return CreateResult{}, err
	}
	return out, nil
}

// Preview calls preview_scan.
func (c *Client) Preview(ctx context.Context, req PreviewRequest) (PreviewResult, error) {
	args := map[string]any{}
	if len(req.Filters) > 0 {
		args["filters"] = encodeFilters(req.Filters)
	}
	if len(req.Columns) > 0 {
		args["columns"] = encodeColumns(req.Columns)
	}
	var out PreviewResult
	if err := c.parse(ctx, toolPreview, args, &out); err != nil {
		return PreviewResult{}, err
	}
	return out, nil
}

// Run calls run_scan. scan_id is always sent (required).
func (c *Client) Run(ctx context.Context, req RunRequest) (RunResult, error) {
	var out RunResult
	if err := c.parse(ctx, toolRun, map[string]any{"scan_id": req.ScanID}, &out); err != nil {
		return RunResult{}, err
	}
	return out, nil
}

// UpdateFilters calls update_scan_filters. scan_id and filters are always sent (required; empty filters clears).
func (c *Client) UpdateFilters(ctx context.Context, req UpdateFiltersRequest) (UpdateFiltersResult, error) {
	filters := req.Filters
	if filters == nil {
		filters = []Filter{}
	}
	args := map[string]any{
		"scan_id": req.ScanID,
		"filters": encodeFilters(filters),
	}
	var out UpdateFiltersResult
	if err := c.parse(ctx, toolUpdateFilters, args, &out); err != nil {
		return UpdateFiltersResult{}, err
	}
	return out, nil
}

// UpdateConfig calls update_scan_config. scan_id is always sent (required).
func (c *Client) UpdateConfig(ctx context.Context, req UpdateConfigRequest) (UpdateConfigResult, error) {
	args := map[string]any{"scan_id": req.ScanID}
	if req.SortingColumn != "" {
		args["sorting_column"] = req.SortingColumn
	}
	if req.SortingDirection != "" {
		args["sorting_direction"] = req.SortingDirection
	}
	if len(req.Columns) > 0 {
		args["columns"] = encodeColumns(req.Columns)
	}
	var out UpdateConfigResult
	if err := c.parse(ctx, toolUpdateConfig, args, &out); err != nil {
		return UpdateConfigResult{}, err
	}
	return out, nil
}

func encodeFilters(filters []Filter) []map[string]any {
	out := make([]map[string]any, len(filters))
	for i, f := range filters {
		m := map[string]any{}
		if f.FilterType != "" {
			m["filter_type"] = f.FilterType
		}
		if f.Predicate != "" {
			m["predicate"] = f.Predicate
		}
		if len(f.Values) > 0 {
			m["values"] = f.Values
		}
		if f.Interval != "" {
			m["interval"] = f.Interval
		}
		if f.Length != 0 {
			m["length"] = f.Length
		}
		if f.Plot != "" {
			m["plot"] = f.Plot
		}
		if f.Expression != "" {
			m["expression"] = f.Expression
		}
		if f.DisplayTitle != "" {
			m["display_title"] = f.DisplayTitle
		}
		out[i] = m
	}
	return out
}

func encodeColumns(cols []Column) []map[string]any {
	out := make([]map[string]any, len(cols))
	for i, col := range cols {
		m := map[string]any{}
		if col.DisplayName != "" {
			m["display_name"] = col.DisplayName
		}
		if col.Expression != "" {
			m["expression"] = col.Expression
		}
		if col.Visible != nil {
			m["visible"] = *col.Visible
		}
		if col.Order != nil {
			m["order"] = *col.Order
		}
		out[i] = m
	}
	return out
}

func (c *Client) parse(ctx context.Context, tool string, args map[string]any, dest any) error {
	raw, err := c.c.Call(ctx, tool, args)
	if err != nil {
		return err
	}
	if err := json.Unmarshal(wire.Unwrap(raw), dest); err != nil {
		return client.ToolErrorf(tool, "parse: %w", err)
	}
	return nil
}