// Cthulhu screen reader.
// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along with
// this program. If not, see <https://www.gnu.org/licenses/gpl-3.0.html>.

package app

import (
	"context"
	"errors"
	"fmt"
	"log/slog"
	"strings"

	"git.stormux.org/storm/cthulhu/internal/atspi"
	"git.stormux.org/storm/cthulhu/internal/input"
	"git.stormux.org/storm/cthulhu/internal/presentation"
	"git.stormux.org/storm/cthulhu/internal/review"
	"git.stormux.org/storm/cthulhu/internal/sound"
)

func documentReviewCommand(command input.Command) (review.DocumentTarget, int, bool) {
	switch command {
	case input.DocumentNextHeading:
		return review.DocumentHeading, 0, false
	case input.DocumentPreviousHeading:
		return review.DocumentHeading, 0, true
	case input.DocumentNextHeadingAtLevel1:
		return review.DocumentHeading, 1, false
	case input.DocumentPreviousHeadingAtLevel1:
		return review.DocumentHeading, 1, true
	case input.DocumentNextHeadingAtLevel2:
		return review.DocumentHeading, 2, false
	case input.DocumentPreviousHeadingAtLevel2:
		return review.DocumentHeading, 2, true
	case input.DocumentNextHeadingAtLevel3:
		return review.DocumentHeading, 3, false
	case input.DocumentPreviousHeadingAtLevel3:
		return review.DocumentHeading, 3, true
	case input.DocumentNextHeadingAtLevel4:
		return review.DocumentHeading, 4, false
	case input.DocumentPreviousHeadingAtLevel4:
		return review.DocumentHeading, 4, true
	case input.DocumentNextHeadingAtLevel5:
		return review.DocumentHeading, 5, false
	case input.DocumentPreviousHeadingAtLevel5:
		return review.DocumentHeading, 5, true
	case input.DocumentNextHeadingAtLevel6:
		return review.DocumentHeading, 6, false
	case input.DocumentPreviousHeadingAtLevel6:
		return review.DocumentHeading, 6, true
	case input.DocumentNextLink:
		return review.DocumentLink, 0, false
	case input.DocumentPreviousLink:
		return review.DocumentLink, 0, true
	case input.DocumentNextButton:
		return review.DocumentButton, 0, false
	case input.DocumentPreviousButton:
		return review.DocumentButton, 0, true
	case input.DocumentNextCheckBox:
		return review.DocumentCheckBox, 0, false
	case input.DocumentPreviousCheckBox:
		return review.DocumentCheckBox, 0, true
	case input.DocumentNextList:
		return review.DocumentList, 0, false
	case input.DocumentPreviousList:
		return review.DocumentList, 0, true
	case input.DocumentNextSeparator:
		return review.DocumentSeparator, 0, false
	case input.DocumentPreviousSeparator:
		return review.DocumentSeparator, 0, true
	case input.DocumentNextBlockQuote:
		return review.DocumentBlockQuote, 0, false
	case input.DocumentPreviousBlockQuote:
		return review.DocumentBlockQuote, 0, true
	case input.DocumentNextComboBox:
		return review.DocumentComboBox, 0, false
	case input.DocumentPreviousComboBox:
		return review.DocumentComboBox, 0, true
	case input.DocumentNextEntry:
		return review.DocumentEntry, 0, false
	case input.DocumentPreviousEntry:
		return review.DocumentEntry, 0, true
	case input.DocumentNextFormField:
		return review.DocumentFormField, 0, false
	case input.DocumentPreviousFormField:
		return review.DocumentFormField, 0, true
	case input.DocumentNextImage:
		return review.DocumentImage, 0, false
	case input.DocumentPreviousImage:
		return review.DocumentImage, 0, true
	case input.DocumentNextLandmark:
		return review.DocumentLandmark, 0, false
	case input.DocumentPreviousLandmark:
		return review.DocumentLandmark, 0, true
	case input.DocumentNextListItem:
		return review.DocumentListItem, 0, false
	case input.DocumentPreviousListItem:
		return review.DocumentListItem, 0, true
	case input.DocumentNextLiveRegion:
		return review.DocumentLiveRegion, 0, false
	case input.DocumentPreviousLiveRegion:
		return review.DocumentLiveRegion, 0, true
	case input.DocumentNextParagraph:
		return review.DocumentParagraph, 0, false
	case input.DocumentPreviousParagraph:
		return review.DocumentParagraph, 0, true
	case input.DocumentNextRadioButton:
		return review.DocumentRadioButton, 0, false
	case input.DocumentPreviousRadioButton:
		return review.DocumentRadioButton, 0, true
	case input.DocumentNextTable:
		return review.DocumentTable, 0, false
	case input.DocumentPreviousTable:
		return review.DocumentTable, 0, true
	case input.DocumentNextUnvisitedLink:
		return review.DocumentUnvisitedLink, 0, false
	case input.DocumentPreviousUnvisitedLink:
		return review.DocumentUnvisitedLink, 0, true
	case input.DocumentNextVisitedLink:
		return review.DocumentVisitedLink, 0, false
	case input.DocumentPreviousVisitedLink:
		return review.DocumentVisitedLink, 0, true
	case input.DocumentNextClickable:
		return review.DocumentClickable, 0, false
	case input.DocumentPreviousClickable:
		return review.DocumentClickable, 0, true
	case input.DocumentNextChunk:
		return review.DocumentChunk, 0, false
	case input.DocumentPreviousChunk:
		return review.DocumentChunk, 0, true
	}
	return 0, 0, false
}

func documentCaretCommand(command input.Command) review.DocumentCaretCommand {
	switch command {
	case input.DocumentTableLeft:
		return review.TableLeft
	case input.DocumentTableRight:
		return review.TableRight
	case input.DocumentTableUp:
		return review.TableUp
	case input.DocumentTableDown:
		return review.TableDown
	case input.DocumentTableFirst:
		return review.TableFirst
	case input.DocumentTableLast:
		return review.TableLast

	case input.DocumentCaretNextCharacter:
		return review.CaretNextCharacter
	case input.DocumentCaretPreviousCharacter:
		return review.CaretPreviousCharacter
	case input.DocumentCaretNextWord:
		return review.CaretNextWord
	case input.DocumentCaretPreviousWord:
		return review.CaretPreviousWord
	case input.DocumentCaretNextLine:
		return review.CaretNextLine
	case input.DocumentCaretPreviousLine:
		return review.CaretPreviousLine
	case input.DocumentCaretLineStart:
		return review.CaretLineStart
	case input.DocumentCaretLineEnd:
		return review.CaretLineEnd
	case input.DocumentCaretDocumentStart:
		return review.CaretDocumentStart
	case input.DocumentCaretDocumentEnd:
		return review.CaretDocumentEnd
	}
	return 0
}

func presentDocumentCaretResult(logger *slog.Logger, speech speechEnqueuer, result review.Result, options presentation.Options) {
	if logger.Enabled(context.Background(), slog.LevelDebug) {
		logger.Debug("document caret navigation completed", "elapsed", result.Elapsed,
			"capture_duration", result.CaptureDuration, "capture_reason", result.CaptureReason,
			"moved", result.Moved, "command", result.DocumentCaretCommand.String(),
			"bus", result.DocumentPosition.Object.ID().BusName,
			"source_path", result.DocumentPosition.Object.ID().Path,
			"virtual_caret_offset", result.DocumentPosition.Offset,
			"native_text_start", result.DocumentCaretStart, "native_text_end", result.DocumentCaretEnd,
			"line_fragments", document_line_ranges(result.DocumentCaretLine),
			"caret_sync_error", result.CaretErr,
			"braille_line_available", result.DocumentBrailleLine != nil || result.DocumentCaretLine != nil,
			"braille_read_error", result.DocumentBrailleErr)
	}
	if result.Err != nil {
		logger.Warn("document caret navigation failed", "error", result.Err)
		speech.Enqueue(speechRequest{Text: "Could not find current location.", Role: "system", Cause: "document-caret"})
		return
	}
	if !result.Moved && result.DocumentCaretText == "" {
		return
	}
	text := result.DocumentCaretText
	if text == " " {
		text = "space"
	}
	if text == "\n" {
		if !options.SpeakBlankLines {
			return
		}
		text = "blank"
	}
	request := speechRequest{Text: text, Role: result.DocumentPosition.Snapshot.Role, Cause: "document-caret"}
	request.Context = result.DocumentCaretContext
	if len(request.Context) > 0 && request.Context[0].ID() == result.DocumentPosition.Snapshot.ID() {
		request.Context = request.Context[1:]
	}
	if result.DocumentCaretCommand >= review.TableLeft && result.DocumentCaretCommand <= review.TableLast {
		snapshot := result.DocumentPosition.Snapshot
		prefix := result.DocumentTablePrefix
		if result.Moved && options.SpeechVerbosityLevel != 0 && prefix != "" &&
			(result.DocumentTableRowHeader != "" || result.DocumentTableColumnHeader != "") {
			parts := []string{
				presentation.TableHeaderText(result.DocumentTableRowHeader, "row header", options.SpeechVerbosityLevel),
				presentation.TableHeaderText(result.DocumentTableColumnHeader, "column header", options.SpeechVerbosityLevel),
			}
			prefix = strings.TrimSpace(strings.Join(parts, " "))
			if strings.HasPrefix(request.Text, result.DocumentTablePrefix+" ") {
				request.Text = prefix + strings.TrimPrefix(request.Text, result.DocumentTablePrefix)
			}
		}
		if result.Moved && options.Reading != nil && options.Reading.OnlySpeakDisplayedText {
			request.Text = snapshot.Name
		}
		vertical := result.DocumentCaretCommand != review.TableLeft && result.DocumentCaretCommand != review.TableRight
		if result.Moved && vertical && snapshot.TableRowText != "" && presentation.FullRowEnabled(snapshot, options) {
			if options.Reading != nil && options.Reading.OnlySpeakDisplayedText {
				request.Text = snapshot.TableRowText
			} else {
				request.Text = strings.TrimSpace(strings.Join([]string{prefix, snapshot.TableRowText, result.DocumentTableSuffix}, " "))
			}
		}
	}
	for _, ancestor := range result.DocumentCaretContext {
		if ancestor.Role == "link" {
			request.VoiceType = "hyperlink"
			break
		}
	}
	switch result.DocumentCaretCommand {
	case review.CaretNextCharacter, review.CaretPreviousCharacter, review.CaretLineStart, review.CaretLineEnd:
		request.Character = true
	case review.CaretNextLine, review.CaretPreviousLine, review.CaretDocumentStart, review.CaretDocumentEnd,
		review.CaretNextWord, review.CaretPreviousWord:
		line := atspi.DocumentLine{Contents: []atspi.DocumentContent{{Snapshot: result.DocumentPosition.Snapshot, Text: text, RawText: result.DocumentCaretRawText}}}
		if result.DocumentCaretCommand != review.CaretNextWord && result.DocumentCaretCommand != review.CaretPreviousWord {
			request.Line = document_speech_line(line)
		}
		roles := map[string]bool{result.DocumentPosition.Snapshot.Role: true}
		// Chromium commonly exposes link/heading text in static descendants.
		// Python's web _generateRoleName includes those ancestor roles. Keep
		// their identity separate from the leaf which owns the caret offset.
		for _, ancestor := range result.DocumentCaretContext {
			if (ancestor.Role != "link" && ancestor.Role != "heading") || roles[ancestor.Role] {
				continue
			}
			roles[ancestor.Role] = true
			ancestor.Name = ""
			line.Contents = append(line.Contents, atspi.DocumentContent{Snapshot: ancestor})
		}
		spoken := presentation.DocumentLineSpeechWithOptions(line, options)
		request.Text, request.Chunks = spoken.Text, spoken.Chunks
		request.Sound = presentation.DocumentLineSoundCues(line, options)
		fallback := options
		fallback.RoleSoundPresentation = "sound_and_speech"
		fallbackSpeech := presentation.DocumentLineSpeechWithOptions(line, fallback)
		request.FallbackText, request.FallbackChunks = fallbackSpeech.Text, fallbackSpeech.Chunks
	}
	speech.Interrupt()
	if request.Text == "" && len(request.Sound) == 0 {
		return
	}
	speech.Enqueue(request)
}

func document_line_ranges(line *atspi.DocumentLine) []map[string]any {
	if line == nil {
		return nil
	}
	ranges := make([]map[string]any, 0, len(line.Contents))
	for _, content := range line.Contents {
		ranges = append(ranges, map[string]any{"bus": content.Snapshot.BusName,
			"source_path": content.Snapshot.Path, "native_text_start": content.Start,
			"native_text_end": content.End, "bounds": content.Bounds})
	}
	return ranges
}

func documentResultMatchesCurrent(result review.Result, current atspi.Snapshot) bool {
	if result.DocumentFocus == current.ID() {
		return true
	}
	return result.Moved && result.Err == nil &&
		result.DocumentPosition.Snapshot.ID() == current.ID()
}

func presentDocumentResult(logger *slog.Logger, speech speechEnqueuer, result review.Result, options presentation.Options) {
	if logger.Enabled(context.Background(), slog.LevelDebug) {
		logger.Debug("document navigation completed", "elapsed", result.Elapsed,
			"capture_duration", result.CaptureDuration, "capture_reason", result.CaptureReason,
			"moved", result.Moved, "target", result.DocumentTarget,
			"level", result.DocumentLevel, "backwards", result.DocumentBackwards,
			"bus", result.DocumentPosition.Object.ID().BusName,
			"source_path", result.DocumentPosition.Object.ID().Path,
			"virtual_caret_offset", result.DocumentPosition.Offset,
			"caret_sync_error", result.CaretErr,
			"sound_geometry_error", result.DocumentSoundErr,
			"braille_line_available", result.DocumentBrailleLine != nil,
			"braille_read_error", result.DocumentBrailleErr)
	}
	text, fallbackText, role := "", "", "system"
	var spoken, fallbackSpeech presentation.Speech
	var cues []sound.Cue
	switch {
	case errors.Is(result.Err, atspi.ErrNotInDocument):
		text = "Not in web document content."
	case result.Err != nil:
		logger.Warn("document navigation failed", "error", result.Err)
		text = "Could not find current location."
	case !result.Moved:
		switch result.DocumentTarget {
		case review.DocumentHeading:
			if result.DocumentLevel == 0 {
				text = "No more headings."
			} else {
				text = fmt.Sprintf("No more headings at level %d.", result.DocumentLevel)
			}
		case review.DocumentLink:
			text = "No more links."
		case review.DocumentButton:
			text = "No more buttons."
		case review.DocumentCheckBox:
			text = "No more check boxes."
		case review.DocumentList:
			text = "No more lists."
		case review.DocumentSeparator:
			text = "No more separators."
		case review.DocumentBlockQuote:
			text = "No more blockquotes."
		case review.DocumentComboBox:
			text = "No more combo boxes."
		case review.DocumentEntry:
			text = "No more entries."
		case review.DocumentFormField:
			text = "No more form fields."
		case review.DocumentImage:
			text = "No more images."
		case review.DocumentLandmark:
			text = "No landmark found."
		case review.DocumentListItem:
			text = "No more list items."
		case review.DocumentLiveRegion:
			text = "No more live regions."
		case review.DocumentParagraph:
			text = "No more paragraphs."
		case review.DocumentRadioButton:
			text = "No more radio buttons."
		case review.DocumentTable:
			text = "No more tables."
		case review.DocumentUnvisitedLink:
			text = "No more unvisited links."
		case review.DocumentVisitedLink:
			text = "No more visited links."
		case review.DocumentClickable:
			text = "No more clickables."
		case review.DocumentChunk:
			text = "No more large objects."
		}
	default:
		if link := result.DocumentPosition.LinkedHeading; link != nil {
			roleOnly := *link
			roleOnly.Name, roleOnly.Text = "", ""
			line := atspi.DocumentLine{Contents: []atspi.DocumentContent{
				{Snapshot: result.DocumentPosition.Snapshot}, {Snapshot: roleOnly},
			}}
			spoken = presentation.DocumentLineSpeechWithOptions(line, options)
			text = spoken.Text
			cues = presentation.DocumentLineSoundCues(line, options)
			fallbackOptions := options
			fallbackOptions.RoleSoundPresentation = "sound_and_speech"
			fallbackSpeech = presentation.DocumentLineSpeechWithOptions(line, fallbackOptions)
			fallbackText = fallbackSpeech.Text
		} else {
			spoken = presentation.FocusSpeechWithOptions(result.DocumentPosition.Snapshot, options)
			text = spoken.Text
			cues = presentation.SoundCues(result.DocumentPosition.Snapshot, options)
			if options.RoleSoundPresentation == "sound_only" {
				fallbackOptions := options
				fallbackOptions.RoleSoundPresentation = "sound_and_speech"
				fallbackSpeech = presentation.FocusSpeechWithOptions(result.DocumentPosition.Snapshot, fallbackOptions)
				fallbackText = fallbackSpeech.Text
			}
		}
		if len(cues) > 0 && logger.Enabled(context.Background(), slog.LevelDebug) {
			// Record the captured geometry actually used for cue generation.
			// Linked headings use the link's geometry independently of the heading.
			attributes := []any{
				"bus", result.DocumentPosition.Snapshot.BusName,
				"source_path", result.DocumentPosition.Snapshot.Path,
				"role", result.DocumentPosition.Snapshot.Role,
				"spatialize_object_sounds", options.SpatializeObjectSounds,
				"sound_geometry", result.DocumentPosition.Snapshot.SoundGeometry,
				"cues", cues,
			}
			if link := result.DocumentPosition.LinkedHeading; link != nil {
				attributes = append(attributes,
					"linked_heading_bus", link.BusName,
					"linked_heading_path", link.Path,
					"linked_heading_sound_geometry", link.SoundGeometry)
			}
			logger.Debug("document navigation sound positioning", attributes...)
		}
		role = result.DocumentPosition.Snapshot.Role
		if result.DocumentWrapped {
			if result.DocumentBackwards {
				spoken = spoken.Append("Wrapping to bottom.", ". ")
				text = spoken.Text
				fallbackSpeech = fallbackSpeech.Append("Wrapping to bottom.", ". ")
				fallbackText = fallbackSpeech.Text
			} else {
				spoken = spoken.Append("Wrapping to top.", ". ")
				text = spoken.Text
				fallbackSpeech = fallbackSpeech.Append("Wrapping to top.", ". ")
				fallbackText = fallbackSpeech.Text
			}
		}
		if result.CaretErr != nil {
			logger.Warn("document caret synchronization failed", "error", result.CaretErr)
			spoken = spoken.Append("Could not move the browser caret.", ". ")
			text = spoken.Text
			fallbackSpeech = fallbackSpeech.Append("Could not move the browser caret.", ". ")
			fallbackText = fallbackSpeech.Text
		}
	}
	speech.Interrupt()
	voiceType := ancestor_voice(result.DocumentCaretContext)
	if result.DocumentPosition.LinkedHeading != nil {
		voiceType = "hyperlink"
	}
	ancestors := result.DocumentCaretContext
	if len(ancestors) > 0 && ancestors[0].ID() == result.DocumentPosition.Snapshot.ID() {
		ancestors = ancestors[1:]
	}
	speech.Enqueue(speechRequest{Text: text, Chunks: spoken.WithText(text).Chunks, FallbackText: fallbackText, FallbackChunks: fallbackSpeech.WithText(fallbackText).Chunks, Role: role, Sound: cues, Cause: "document-navigation", Context: ancestors, VoiceType: voiceType})
}