diffview

type Analysis struct {
	Type    string          // e.g., "story", "security", "complexity"
	Payload json.RawMessage // Type-specific JSON payload
}

type AnnotatedHunk struct {
	ID   string // Unique identifier for referencing in analysis
	Hunk Hunk
}

type ClassificationInput struct {
	Repo          string        `json:"repo"`
	Branch        string        `json:"branch"`
	PRTitle       string        `json:"pr_title,omitempty"`
	PRDescription string        `json:"pr_description,omitempty"`
	Commits       []CommitBrief `json:"commits"`
	Diff          Diff          `json:"diff"`
}

type Clipboard interface {
	Copy(content string) error
}

type Color string

type ColorPair struct {
	Foreground string
	Background string
}

type CommitBrief struct {
	Hash    string `json:"hash"`
	Message string `json:"message"`
	Diff    *Diff  `json:"diff,omitempty"`
}

type DefaultFormatter struct{}

type Diff struct {
	Files []FileDiff
}

type DiffAnalysis struct {
	Version  int        // Schema version for forward compatibility
	Analyses []Analysis // Multiple analysis types can be included
}

type EvalCase struct {
	Input ClassificationInput  `json:"input"` // The input for classification
	Story *StoryClassification `json:"story"` // The LLM-generated classification (nil if not yet classified)
}

type EvalCaseLoader interface {
	Load(path string) ([]EvalCase, error)
}

type EvalCaseSaver interface {
	Save(path string, c EvalCase) error
}

type FileDiff struct {
	OldPath   string      // "a/file.go" or empty for new files
	NewPath   string      // "b/file.go" or empty for deleted files
	Operation FileOp      // Added, Deleted, Modified, Renamed, Copied
	IsBinary  bool        // Binary files have no hunks
	OldMode   fs.FileMode // 0 if unchanged
	NewMode   fs.FileMode // For permission changes
	Hunks     []Hunk
	Extended  []string // Raw extended headers for passthrough
}

type FileOp int

type GitRunner interface {
	// Log returns commit hashes from the repository at repoPath, limited to n commits.
	// Deprecated: Use MergeCommits for PR-level extraction.
	Log(ctx context.Context, repoPath string, limit int) ([]string, error)
	// Show returns the diff for a specific commit hash.
	// Deprecated: Use DiffRange for PR-level extraction.
	Show(ctx context.Context, repoPath string, hash string) (string, error)
	// Message returns the commit message for a specific commit hash.
	// Deprecated: Use CommitsInRange for PR-level extraction.
	Message(ctx context.Context, repoPath string, hash string) (string, error)

	// MergeCommits returns merge commit hashes from the repository, limited to n commits.
	// Used to find PR boundaries in git history.
	MergeCommits(ctx context.Context, repoPath string, limit int) ([]string, error)
	// CommitsInRange returns commits between base and head (base exclusive, head inclusive).
	// For a merge commit, use merge^1..merge^2 to get all PR commits.
	CommitsInRange(ctx context.Context, repoPath, base, head string) ([]CommitBrief, error)
	// DiffRange returns the combined diff between base and head.
	// Uses three-dot notation (base...head) to show changes introduced by head since common ancestor.
	DiffRange(ctx context.Context, repoPath, base, head string) (string, error)
	// Diff returns the diff for a raw range specification (e.g., "main...feature" or "HEAD~3..HEAD").
	// The rangeSpec is passed directly to git diff, supporting both two-dot and three-dot notation.
	Diff(ctx context.Context, repoPath, rangeSpec string) (string, error)
	// CurrentBranch returns the name of the currently checked out branch.
	CurrentBranch(ctx context.Context, repoPath string) (string, error)
	// MergeBase returns the best common ancestor commit between two refs.
	MergeBase(ctx context.Context, repoPath, ref1, ref2 string) (string, error)
	// DefaultBranch returns the default branch name from origin/HEAD.
	// Returns an error if no remote is configured.
	DefaultBranch(ctx context.Context, repoPath string) (string, error)
}

type Hunk struct {
	OldStart int    // From @@ -X,...
	OldCount int    // From @@ -X,Y ...
	NewStart int    // From @@ ...,+X
	NewCount int    // From @@ ...,+X,Y
	Section  string // Optional function name after @@ ... @@
	Lines    []Line
}

type HunkRef struct {
	File         string `json:"file"`
	HunkIndex    int    `json:"hunk_index"`
	Category     string `json:"category"`                // refactoring, systematic, core, noise
	Collapsed    bool   `json:"collapsed"`               // Whether to collapse in viewer
	CollapseText string `json:"collapse_text,omitempty"` // Summary when collapsed
}

type Judgment struct {
	CaseID   string    `json:"case_id"`   // Links to EvalCase.Input.CaseID() (repo/branch)
	Index    int       `json:"index"`     // Position in input file (0-based)
	Judged   bool      `json:"judged"`    // Whether pass/fail has been explicitly set
	Pass     bool      `json:"pass"`      // Whether the classification is acceptable
	Critique string    `json:"critique"`  // Explanation for failure (empty if pass)
	JudgedAt time.Time `json:"judged_at"` // When judgment was recorded
}

type JudgmentStore interface {
	Load(path string) ([]Judgment, error)
	Save(path string, judgments []Judgment) error
}

type LanguageDetector interface {
	// DetectFromPath returns the language name for the given path,
	// or an empty string if the language cannot be determined.
	// Accepts paths with or without "a/" or "b/" prefixes (common in diffs).
	DetectFromPath(path string) string
}

type Line struct {
	Type       LineType
	Content    string
	OldLineNum int  // 0 if line is Added
	NewLineNum int  // 0 if line is Deleted
	NoNewline  bool // "\ No newline at end of file" marker
}

type LineType int

type Palette struct {
	// Base colors
	Background Color // Primary background
	Foreground Color // Primary foreground/text

	// Diff colors
	Added    Color // Added lines and text
	Deleted  Color // Deleted lines and text
	Modified Color // Modified content
	Context  Color // Unchanged context lines

	// Syntax highlighting colors
	Keyword     Color // Language keywords (if, for, func, etc.)
	String      Color // String literals
	Number      Color // Numeric literals
	Comment     Color // Comments
	Operator    Color // Operators (+, -, =, etc.)
	Function    Color // Function names
	Type        Color // Type names
	Constant    Color // Constants and boolean literals
	Punctuation Color // Brackets, semicolons, etc.

	// UI colors
	UIBackground Color // Secondary background (panels, sidebars)
	UIForeground Color // Secondary foreground (dimmed text)
	UIAccent     Color // Accent color (highlights, focus)
}

type Parser interface {
	// Parse reads diff content and returns the parsed result.
	Parse(r io.Reader) (*Diff, error)
}

type PromptFormatter interface {
	Format(input ClassificationInput) string
}

type RubricJudge interface {
	// Judge evaluates whether the output satisfies the given criterion.
	Judge(ctx context.Context, criterion, output string) (*RubricResult, error)
}

type RubricResult struct {
	Passed    bool   // Whether the output satisfied the criterion
	Reasoning string // LLM's explanation for the judgment
}

type Section struct {
	Role        string    `json:"role"`        // problem, fix, test, core, supporting, etc.
	Title       string    `json:"title"`       // Human-readable section title
	Hunks       []HunkRef `json:"hunks"`       // References to hunks in this section
	Explanation string    `json:"explanation"` // Why this section matters
}

type Segment struct {
	Text    string // The text content of this segment
	Changed bool   // True if this segment differs between old/new versions
}

type StoryAnalysis struct {
	ChangeType string      `json:"change_type"` // e.g., "refactor", "feature", "bugfix"
	Summary    string      `json:"summary"`     // One-line description of what changed
	Parts      []StoryPart `json:"parts"`       // Ordered sequence of change components
}

type StoryClassification struct {
	ChangeType string    `json:"change_type"`         // bugfix, feature, refactor, chore, docs
	Narrative  string    `json:"narrative"`           // cause-effect, core-periphery, before-after, etc.
	Summary    string    `json:"summary"`             // One sentence describing the change
	Sections   []Section `json:"sections"`            // Ordered sections grouping related hunks
	Evolution  string    `json:"evolution,omitempty"` // How changes evolved across commits
}

type StoryClassifier interface {
	Classify(ctx context.Context, input ClassificationInput) (*StoryClassification, error)
}

type StoryGenerator interface {
	// Generate creates a DiffAnalysis from annotated hunks.
	Generate(ctx context.Context, hunks []AnnotatedHunk) (*DiffAnalysis, error)
}

type StoryPart struct {
	Role        string   `json:"role"`        // e.g., "setup", "core", "cleanup"
	HunkIDs     []string `json:"hunk_ids"`    // References to AnnotatedHunk IDs
	Explanation string   `json:"explanation"` // Human-readable description of this part
}

type Style struct {
	Foreground string // Hex color code (e.g., "#ff0000") or empty for default
	Bold       bool   // Whether the text should be bold
}

type Styles struct {
	Added            ColorPair // Style for added lines (+)
	Deleted          ColorPair // Style for deleted lines (-)
	Context          ColorPair // Style for context lines (unchanged)
	HunkHeader       ColorPair // Style for hunk headers (@@ ... @@)
	FileHeader       ColorPair // Style for file headers (--- a/... +++ b/...)
	FileSeparator    ColorPair // Style for separator lines between files
	LineNumber       ColorPair // Style for line numbers in the gutter (context lines)
	AddedGutter      ColorPair // Style for gutter on added lines (stronger background)
	DeletedGutter    ColorPair // Style for gutter on deleted lines (stronger background)
	AddedHighlight   ColorPair // Style for changed text within added lines (word-level diff)
	DeletedHighlight ColorPair // Style for changed text within deleted lines (word-level diff)
}

type Theme interface {
	Styles() Styles
	Palette() Palette
}

type Token struct {
	Text  string // The text content of this token
	Style Style  // Visual style to apply (colors, bold, etc.)
}

type Tokenizer interface {
	// Tokenize splits source code into syntax-highlighted tokens for the given language.
	// Returns nil if the language is not supported.
	Tokenize(language, source string) []Token

	// TokenizeLines tokenizes multi-line source code with full context,
	// returning tokens split by line. This correctly handles multi-line
	// constructs like /* */ comments and JSDoc.
	// Returns nil if the language is not supported.
	TokenizeLines(language, source string) [][]Token
}

type ValidationError struct {
	Section   int              // Index of the section containing the error
	HunkRef   HunkRef          // The problematic hunk reference
	Reason    ValidationReason // Why this reference is invalid
	HunkCount int              // Actual hunk count for the file (for invalid_index errors)
}

type ValidationReason string

type Viewer interface {
	// View displays the diff and blocks until the user exits.
	View(ctx context.Context, diff *Diff) error
}

type WordDiffer interface {
	// Diff returns segments for both the old and new strings,
	// marking which portions changed between them.
	Diff(old, new string) (oldSegs, newSegs []Segment)
}