stats

type Comparison struct {
	Prompts             Delta
	Turns               Delta
	InputTokens         Delta
	CacheCreationTokens Delta
	CacheReadTokens     Delta
	OutputTokens        Delta
	TotalTokens         Delta
	CostUSD             Delta
}

type CostBreakdownReport struct {
	Overall   ModelBreakdown // Model = "overall"
	ByModel   []ModelBreakdown
	TotalCost float64
}

type CostBucket struct {
	Kind   string // "input" | "cache_write_5m" | "cache_write_1h" | "cache_read" | "output"
	Tokens int
	Rate   float64
	Cost   float64
	Pct    float64 // 0..100, share of total cost (the parent ModelBreakdown.TotalCost or overall)
}

type DayStat struct {
	Day     string
	Totals  Totals
	ByModel map[string]Totals
}

type Delta struct {
	A     float64 // value for range A
	B     float64 // value for range B
	Delta float64 // B - A (absolute; negative means B < A)
	Pct   float64 // (B - A) / A * 100; 0.0 when A == 0
	Gt    bool    // true when B > A strictly
}

type FilterPreset int

type ModelBreakdown struct {
	Model     string
	Buckets   []CostBucket
	TotalCost float64
	Pct       float64 // share of grand total across all models
}

type ModelStat struct {
	Model  string
	Totals Totals
}

type ProjectStat struct {
	Cwd    string
	Totals Totals
}

type Report struct {
	Overall       Totals
	ByDay         []DayStat
	ByModel       []ModelStat
	BySession     []SessionStat
	ByProject     []ProjectStat
	Tools         ToolStats
	Models        []string // stable list of model names seen (sorted by total usage desc)
	DateRange     [2]time.Time
	PromptsByHour [24]int // prompts per hour-of-day aggregated across all filtered data
}

type SessionDetail struct {
	SessionID string
	Cwd       string
	FirstSeen time.Time
	LastSeen  time.Time
	Models    []string      // sorted, unique
	Totals    Totals        // session totals
	Turns     []SessionTurn // chronological, oldest first
}

type SessionStat struct {
	SessionID string
	Cwd       string
	FirstSeen time.Time
	LastSeen  time.Time
	Models    map[string]struct{}
	Totals    Totals
}

type SessionTurn struct {
	Timestamp time.Time
	Model     string
	// Totals is the usage of this single Event (not cumulative).
	Totals Totals
	// Tools contains the tool_use items the assistant emitted in this turn.
	// Empty if the turn had no tool calls.
	Tools []string
}

type ToolEntry struct {
	Name  string
	Count int
}

type ToolStats struct {
	Builtins []ToolEntry
	MCPs     []ToolEntry // aggregated per tool name ("server/tool")
	Servers  []ToolEntry // aggregated per MCP server
	Skills   []ToolEntry
	Agents   []ToolEntry
	Total    int
}

type Totals struct {
	InputTokens           int
	OutputTokens          int
	CacheCreationTokens   int // total = 5m + 1h (kept for backwards compat)
	CacheCreation5mTokens int
	CacheCreation1hTokens int
	CacheReadTokens       int
	Turns                 int
	Prompts               int
	Cost                  float64 // USD, summed per-event
}