package gherkin

import (
	"reflect"
	"strings"
)

// Feature represents the top-most construct in a Gherkin document. A feature
// contains one or more scenarios, which in turn contains multiple steps.
type Feature struct {
	// The filename where the feature was defined
	Filename string

	// The line number where the feature was defined
	Line int

	// The feature's title.
	Title string

	// A longer description of the feature. This is not used during runtime.
	Description string

	// Any tags associated with this feature.
	Tags []string

	// Any background scenario data that is executed prior to scenarios.
	Background Scenario

	// The scenarios associated with this feature.
	Scenarios []Scenario

	// The longest line length in the feature (including title)
	longestLine int
}

// Scenario represents a scenario (or background) of a given feature.
type Scenario struct {
	// The filename where the scenario was defined
	Filename string

	// The line number where the scenario was defined
	Line int

	// The scenario's title. For backgrounds, this is the empty string.
	Title string

	// Any tags associated with this scenario.
	Tags []string

	// All steps associated with the scenario.
	Steps []Step

	// Contains all scenario outline example data, if provided.
	Examples StringData

	// The longest line length in the scenario (including title)
	longestLine int
}

// Step represents an individual step making up a gucumber scenario.
type Step struct {
	// The filename where the step was defined
	Filename string

	// The line number where the step was defined
	Line int

	// The step's "type" (Given, When, Then, And, ...)
	//
	// Note that this field is normalized to the English form (e.g., "Given").
	Type StepType

	// The text contained in the step (minus the "Type" prefix).
	Text string

	// Argument represents multi-line argument data attached to a step.
	Argument StringData
}

// StringData is multi-line docstring text attached to a step.
type StringData string

// TabularData is tabular text data attached to a step.
type TabularData [][]string

// TabularDataMap is tabular text data attached to a step organized in map
// form of the header name and its associated row data.
type TabularDataMap map[string][]string

// StepType represents a given step type.
type StepType string

// ToTable turns StringData type into a TabularData type
func (s StringData) ToTable() TabularData {
	var tabData TabularData
	lines := strings.Split(string(s), "\n")
	for _, line := range lines {
		row := strings.Split(line, "|")
		row = row[1 : len(row)-1]
		for i, c := range row {
			row[i] = strings.TrimSpace(c)
		}
		tabData = append(tabData, row)
	}
	return tabData
}

// IsTabular returns whether the argument data is a table
func (s StringData) IsTabular() bool {
	return len(s) > 0 && s[0] == '|'
}

// ToMap converts a regular table to a map of header names to their row data.
// For example:
//
//     t := TabularData{[]string{"header1", "header2"}, []string{"col1", "col2"}}
//     t.ToMap()
//     // Output:
//     //   map[string][]string{
//     //     "header1": []string{"col1"},
//     //     "header2": []string{"col2"},
//     //   }
func (t TabularData) ToMap() TabularDataMap {
	m := TabularDataMap{}
	if len(t) > 1 {
		for _, th := range t[0] {
			m[th] = []string{}
		}
		for _, tr := range t[1:] {
			for c, td := range tr {
				m[t[0][c]] = append(m[t[0][c]], td)
			}
		}
	}
	return m
}

// NumRows returns the number of rows in a table map
func (t TabularDataMap) NumRows() int {
	if len(t) == 0 {
		return 0
	}
	return len(t[reflect.ValueOf(t).MapKeys()[0].String()])
}

// LongestLine returns the longest step line in a scenario.
func (s *Scenario) LongestLine() int {
	if s.longestLine == 0 {
		s.longestLine = len("Scenario: " + s.Title)
		for _, step := range s.Steps {
			if l := len(string(step.Type) + " " + step.Text); l > s.longestLine {
				s.longestLine = l
			}
		}
	}
	return s.longestLine
}

// LongestLine returns the longest step line in a feature.
func (f *Feature) LongestLine() int {
	if f.longestLine == 0 {
		f.longestLine = len("Feature: " + f.Title)
		for _, s := range f.Scenarios {
			if l := s.LongestLine(); l > f.longestLine {
				f.longestLine = l
			}
		}
	}
	return f.longestLine
}

// FilterMatched returns true if the set of input filters match the feature's tags.
func (f *Feature) FilterMatched(filters ...string) bool {
	return matchTags(f.Tags, filters)
}

// FilterMatched returns true if the set of input filters match the feature's tags.
func (s *Scenario) FilterMatched(f *Feature, filters ...string) bool {
	t := []string{}
	t = append(t, f.Tags...)
	t = append(t, s.Tags...)
	return matchTags(t, filters)
}

func matchTags(tags []string, filters []string) bool {
	if len(filters) == 0 { // no filters means everything passes
		return true
	}
	for _, f := range filters {
		if matchFilter(f, tags) {
			return true // if any filter matches we succeed
		}
	}
	return false
}

func matchFilter(filter string, tags []string) bool {
	parts := strings.Split(filter, ",")
	for _, part := range parts { // all parts must match
		part = strings.TrimSpace(part)
		if part == "" {
			continue
		}

		if part[0] == '~' { // filter has to NOT match any tags
			for _, t := range tags {
				if part[1:] == string(t) { // tag matched, this should not happen
					return false
				}
			}
			// nothing matched, we can continue on
		} else {
			result := false
			for _, t := range tags {
				if part == string(t) { // found a match in a tag
					result = true
					break
				}
			}
			if !result { // no matches, this filter failed
				return false
			}
		}
	}
	return true
}